title: How to train tactics methodically

text:
# Question
Title: How to train tactics methodically
In sports, there are often times methodical ways to practice. In tennis, for example, you don't just play matches or just practice forehands, you practice hitting forehands cross-court deep into the corner target, then to the angled target, etc.

I'm wondering, what is the equivalent method of practicing tactics methodically in chess? Would it be to practice one motif repeatedly? Or is it to practice blitz+standard?

# Answer
> 5 votes
> I'm wondering, what is the equivalent method of practicing tactics methodically in chess? Would it be to practice one motif repeatedly? Or is it to practice blitz+standard?

Neither.

In the chess world it seems to be to use some variation of "spaced repetition". There is a great answer by BlindKungFuMaster to a different question which says:

> Spaced repetition is a learning technique that repeats content after increasing time spans according to learning success, i.e. faster for stuff you haven't grasped yet, longer if you do well.
>
> In chess this is either used to learn a certain set of (easy) tactical exercises basically by heart ("woodpecker method" according to Axel Smith, Michael de la Maza, …), which is supposed to improve your tactical pattern recognition.

Since BlindKungFuMaster's excellent post Axel Smith and Hans Tikkanen have published a book expanding on the "woodpecker method" called "The Woodpecker Method" which includes some interesting history and background together with instructions and explanations of the method plus over 1100 graded exercise.

The main difference between spaced repetition and the woodpecker method is that Smith and Tikkanen emphasize increasing speed rather than time gap. Here are their instructions:

> **Step 1**
> Cycle 1: Solve as many exercises as you can manage in four weeks. These exercises are your set; and solving them brings you to the end of your first cycle. (The exact time period can be adjusted according to your lifestyle and circumstances, but try not to spend much more than four weeks. If you find yourself taking much longer than four weeks, you have probably either not been putting in sufficient time, or have included too many exercises in your set.)

> **Step 2**
> Take a break from chess for at least a clear day, and up to a week if you need it.
>
> **Step 3**
> Cycle 2: Solve the same set of exercises but faster: within two weeks is the target.
>
> **Step 4**
> Repeat steps 2 and 3, and repeat again. Aim to complete each cycle in half the number of days as the previous cycle (rounded up, when dealing with an odd number of days).
>
> **Step 5**
> The Woodpecker Method has been completed when the full set of exercises has been solved entirely in one day – or after the 7th cycle, if you are unable to solve the full set in a day. In the final two cycles, you should focus more on spotting ideas, patterns and motifs at speed, and less on the finer details of calculation.

Interesting to note that Axel Smith credits the woodpecker method (named after the translation of Tikkanen's name into English) with his achievement of the GM title. This is what he says early in the book:

> As mentioned above, I trained with the Woodpecker Method in the spring of 2010. That summer, I achieved three GM norms and surpassed the 2500 barrier, all within a seven-week period. The positive eﬀects did not stop there: the following year, my live rating brieﬂy peaked at 2601.
>
> Such quick results from any type of chess training are rare in my experience, but for me the Woodpecker Method seemed to be just what the doctor ordered! The increased tactical acuity and consistency that came from working so hard with the method significantly decreased my blunders and made me more confident at the board.
>
> Would I have made the same improvement with some other type of training? It’s not impossible – but my playing strength had not taken any significant leap in years, so I had been at a loss as to what to do diﬀerently to succeed. Although the Woodpecker Method probably wasn’t the only way for me to raise my play, it certainly proved to be a way. The intersection of my interest in the human mind and my motivation to stop blundering surely helped me to devote more time and eﬀort than I would have put into my usual training.

# Answer
> 1 votes
> *What is the equivalent method of practicing tactics methodically in chess?*
> Would it be to practice one motif repeatedly? Or is it to practice blitz+standard?

## Preface

Playing standard games goes along with tactics training, but clearly not a part of tactics training at all. Many masters use blitz games as part of tactics training; but whether you should use this practice depends on your experience.

(Quote from https://thechessworld.com/articles/training-techniques/10-little-known-chess-training-methods-that-work/)

> A moderated amount of blitz, online or over the board, can help you keep sharp. Be aware, an overdose of blitz can literally destroy your chess thinking and turn you into a superficial player with very little chances of survival in longer time controls.

If you tend to play too fast in standard games (much less aware than usual) after playing blitz games, I recommend not playing blitz games at all (see the above quote as to why).

# Tactics Training

Tactics training is not just one practice; it is rather comprised of a number closely related practices, each aiming one/more of the following:
(1) Get familiar with a theme (or a motif for that matter)
(2) Spot important themes in a given position
(3) (Tactical) alertness training

NB: I recommend doing them in the given order, that is Practice (1), followed by Practice (2) and finally Practice (3).

## Practice (1)

Practice (1) is done especially when someone learns a theme for the first time. In (1), the player practices a large number of (relatively easy) puzzles of the same theme in one stretch. This can be done with tactics books where there are exercised arranged by theme, or with websites (such as lichess.org) that allow tactics training by theme.

The aim of practice (1) is recognition of a pattern (in simplest setting, at first). Here, the focus is on recognizing the pattern in a large number of puzzles in reasonable time (rather than doing a few hard ones). The hardness level of the set of puzzles can be gradually increased, as long as the player is still able to solve a large number of puzzles in reasonable time (the principle at play here is reward).

Practice (1) can be repeated spaced out a la spaced repetition method with or without targeting to reduce the time taken to solve the problem (the latter is the focus in the woodpecker method explained in Brian Tower's answer). Both spaced repetition and the woodpecker method seem to recommend using the same set of puzzles multiple times in order to learn the set of puzzles basically by heart. I personally recommend against it. I think using a very similar set of puzzles would be more beneficial (how similar works best is a topic worth researching). This is my recommendation because the aim is to get familiar with a particular pattern, not a particular position. At the least, one can make small changes in less relevant parts of the position (relevant relative to the pattern at hand). The downside of this is that you need someone to prepare similar sets of puzzles unless
(i) you are using a website that allow practicing puzzles by theme as well as rating level, or
(ii) you have a large set of puzzles along with hardness level and splitting it up into almost equal smaller sets is easy.

## Practice (2)

Practice (2) is the most commonly available one. Some basically identify tactics training with practice (2). In (2), you are given a position where there are some tactical possibilities (opportunities or threats), and you have to find the best move. Quite often, (2) is a testing ground for familiarity with tactics and also the ability in calculation. Besides, practice (2) tests a player's ability to weight different factors based on their relative importance in the given position. Practice (2) is doable with a large number of chess books (exercises not by theme) and websites such as chess.com, lichess.org, chesstempo.com, etc.

In (2), more often than people realize, mixed tactics/themes is at play. For example, even in tactics training by theme (i.e., (1)), if two puzzles differ in hardness level, say puzzle 2 is harder than puzzle 1, then almost always puzzle 2 involves a larger number of other themes and/or themes at a higher level (different themes involved are usually missed since some themes are less appreciated than others; e.g.: gaining tempo, coercion, reloader, attack/remove the defender, opening/closing lines, trapping pieces).

## Practice (3)

Many players find it easy to solve puzzles, but unable to spot easier ones in their games (see this question for instance). Practice (3) addresses this issue. Here, a set of positions are given, and the question is "What is your move in this position?". A position in the set may or may not involve a tactic, and it may have more than one answers (e.g. depending the plan the player comes up with). This simulates the game situation more closely.

A set of positions with this idea can be found here.

Also, a set will be timed and the player is asked to solve the maximum number of puzzles within the specified time (time should not be too low). Here, not only calculation, but also judgement is tested. The player has to decide which positions require a more thorough calculation. There is no guarantee that there is tactical resource for you (e.g. no automatic sacrifices). Deciding when to calculate deeply is a crucial skill for a serious chess player.

Although there are websites that attempt to do practice (3), their success in doing so is questionable (they succeed better when the number of themes involved in the set is larger and also involve positional themes in addition to tactical themes). It seems to me that puzzles in chesstempo.com have this nature more compared to those in chess.com and lichess (note that choosing tactical positions from games does not simulate game situation). I think a coach can do the job of preparing a set of positions for practice (3) much better (for this practice, only themes the player is closely familiar with should come up in the given position).

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Tags: tactics, training, best-practice
---


title: What is a "club player"?

text:
# Question
Title: What is a "club player"?
I often see this phrase being used in chess articles, apparently used to distinguish these players from professional chess players, grandmasters, etc.

But what exactly are they?

* What Elo range?
* Only players associated with a club?
* Why not call them amateurs?

# Answer
> 14 votes
If you call somebody a club player, you not only distinguish him from professionals and masters (though those obviously play in clubs too), but also from hobbyists. And that distinction makes some sense, because hobby players usually don't reach a strength beyond 1500 Elo or so.

So a club player is somebody who is serious about chess, plays rated games regularly and knows something about the game. He is only implicitly not a master (otherwise you'd call him that). Depending on which distinction you want to stress, you might also call him a "rated player" or an "untitled player".

The term amateur is also often used, but of course, depending on context, an amateur can also be a hobbyist or even a non-professional world class player (like, Euwe, McShane, Malakhov …).

# Answer
> 1 votes
In general, the notion of a club player denotes some level of seriousness about approach to the game, including studying (at least some opening preparation, and certainly tactics practice, and possibly endgame theory), and occasional tournament play, which may or may not be limited to club tournaments. There are certainly patzers in clubs, and amateurs who don't really care about improving, but that's not what the term is intended to describe. See, for example, Kostyev's "40 Lessons for the Club Player", by which he clearly means instruction for *improving* intermediate players.

# Answer
> 1 votes
By definition, a "club player" is someone who follows "organized" chess at a club. They attend lectures by professional players, follow their games, read their books, and play (occasional) simultaneous games with the pros, and more often games with other, similarly inclined players.

While the pros are technically "club" players, the term is used to describe people who are below pro, or at least master, level; that is below ELO 2200 or so. These are "serious" players, usually intermediate to strong, because they play "organized" chess at clubs, that are "amateurs" who are not good enough to make a living at chess.

# Answer
> 0 votes
The clue is in the name - "club player" - somebody who plays chess for a chess club. I'm a member of 2 chess clubs in 2 different countries. I'm a club player as are most, if not all, the players I know. Although I recognize a few players on the congress circuit who don't play club chess and whom I wouldn't regard as club players. The lowest rated is about elo 2000.

In the smaller of the two clubs I play for, where we have 4 teams, the lowest graded player who plays bottom board for the bottom team has a grading which equates to an elo of about 1250 and board 1 on the first team has an elo of just over 2200.

The other is a much bigger club with something in the region of 15 teams. The top team has 2 GMs playing for it, round about the 2400 mark, and the weakest team starts somewhere round about the 1500 mark.

None of the players in either of my two clubs makes a living solely from playing chess. Rather several of them earn some money from coaching. In club 2 one of the GMs, an IM and a couple of players round about the 2100-2200 mark earn some money coaching. In club 1 one of the players rated about the 1950 mark coaches.

I also don't think you can limit the definition according to whether or not a player plays international chess. In club 2 I know of one player rated about 1950 who has played in the last 2 world championships for 65+. He is in his mid 80's. Good luck to him. He should continue enjoying his chess as long as he can, but at the end of the day he is a club player.

So, I don't think you can define a club player by his rating, whether he makes money from chess or whether he plays in international championships. There is enormous overlap. At the end of the day a club player is somebody who plays chess for a chess club.

# Answer
> 0 votes
My chess program (Shredder) assigns Elo levels 1600-1750 for club players and 1750-1900 for strong club players. Tournament players follow with Elo 1900-2050, then experts with Elo 2050-2250.

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Tags: terminology
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# Question
Title: Opposite side castling, pawn storm vs piece play
I used to play Sicilian Najdorf a couple of years ago and I used to get positions like this one:

```
[FEN ""]
1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 a6 6.Be3 e5 7.Nb3 Be6 8.f3 Be7 9.Qd2 Nbd7 10.O-O-O O-O 11.g4 b5

```

In this sicilian position opposite side castling happened and pawn storm is the way to go. However, nowadays, I play the Caro Kann, and when opposite side castling happen in certain lines like the one shown below, according to stockfish, pawn storm is not the way to proceed. Piece pressure and play on the queenside is the way to go

```
[FEN ""]
1.e4 c6 2.Nf3 d5 3.exd5 cxd5 4.d4 Bg4 5.h3 Bxf3 6.Qxf3 e6 7.Nc3 Nc6 8.Be3 Nf6 9.Bb5 Bd6 10.O-O-O Rc8 11.g4 Qa5 12.g5 Nd7 13.h4 O-O! 14.Kb1 Nb4! 15.Bxd7 Rxc3!

```

Or this position

```
[FEN ""]
1.e4 c6 2.Nc3 d5 3.Nf3 dxe4 4.Nxe4 Nf6 5.Nxf6+ exf6 6.d4 Bd6 7.Be3 O-O 8.Qd2 Re8 9. O-O-O Be6 10.Kb1 Na6 11.c4 Nb4 12.Rc1 Bf5+ 13.Ka1 a5 14.a3 Qe7! 15.c5 Bc7

```

My question is: If you're out of book, how do you determine if pawn storm or piece play is better in an opposite side castling position?

# Answer
> 1 votes
If unsure prefer piece play over pawn play. Pawn moves are more committal as they do not move backwards. With pieces you can probe and give your opponent problems but then move the pieces to defense if needed.

Pawn moves can mess up your pawn structure. Keep in mind who has the better ending in the pawn structure.

Pawns are great for grabbing space and threatening to advance against the castled position. Use pawns when you want to create space for freedom of movement for yourself and cramping your opponent. Use pawns to create outposts for your pieces.

---
Tags: strategy, pawn-structure
---


# Question
Title: Books that explain fundamental chess concepts
I am a recreational chess player, hoping to understand the game a little more by reading chess books. I am looking for books that explain each and every move like *Understanding Chess Move By Move* by John Nunn. The only problem with this book is that fundamental concepts like pawn structure and the importance of the center are assumed knowledge. Although I am aware of these concepts, I have no idea why the center is important or how one can take advantage of it if the opponent willingly gives it up. I also do not know why, for example, one sometimes prefer the move Bd3 over Bc4 or vice versa and this is a point which the author does not go over. Sometimes people play Bc4, then trades with the knight. My inexperience tells me that here White played two moves only to lose the bishop, which does not seem ideal in the opening.

I suppose that I am looking for a book which explains all the fundamental concepts but not for complete beginners, either. I am aware of all the basic tactics like forks, pins, etc., and things like Scholar's mate, smothered mate, etc.

What are good books to address these issues and why do you recommend them?

# Answer
> 9 votes
I've focused this answer on resources that have clear, strong writing with good explanations. Some also have puzzles that support the author's presentation of ideas.

When I first started playing chess seriously, I found Yasser Seirawan's ***Play Winning Chess*** a nice introduction to the practical considerations of

* Force (material)
* Time
* Space
* Pawn Structure

and the narrative, games, tips, puzzles, and quizzes explicitly targeting beginners.

Seirawan's ***Winning Chess Strategies*** was a useful foray into basic strategy and helped me come up with plans and evaluate candidate moves better. Very useful chapters relevant to your question such as

* Ch. 4: "Understanding Where the Pieces Go"
* Ch. 5: "Superior Minor Pieces"
* Ch. 6: "How to Use Pawns"

again with easy to follow writing and lots of puzzles and quizzes.

I found ***Best Lessons of a Chess Coach: Extended Edition*** to have useful explanations for piece placement decisions, including how to punish certain moves by the opponent where the explanation covers the "why" and not just the correct lines. This book targets a slightly stronger audience than Seirawan's books, but the narrative (words!) is pretty detailed.

Chernev's ***Logical Chess Move by Move*** is also fairly well known where "\[e\]very single move of every game will be commented on, in simple, everyday language." Games included cover

* The Kingside Attack (16 games)
* The Queen's Pawn Opening (7)
* Other Strong Master Games & Their Ideas (10).

Of course, there are many other great resources. I'm sure fellow answerers will come up with even better recommendations.

Some relevant episodes of *The Perpetual Chess Podcast* with discussions on book resources for these topics mentioned by the OP:

# Answer
> 6 votes
I think that you are looking for a kind of first book on chess strategy, that explains things in words (and not just with puzzles or analysis).

A good example would be *Chess Strategy for Club Players* by Herman Grooten (he is an IM and very experienced coach). But there are many more.

# Answer
> 2 votes
Some solid recommendations:

* *Logical Chess Move By Move* by Irving Chernev. Excellent for those with ratings \<1400.
* *Art of Attack in Chess* by Vladimir Vukovic
* *60 memorable games* by Bobby Fischer
* *How to Reassess Your Chess* by Jeremy Silman

# Answer
> 1 votes
Excellent question! Without any doubt, the most famous book about this topic is "My System," by Aron Nimzowitsch. Some people say that "My System" is difficult to understand. However, another way to view the difficulty of understanding "My System" is that chess is difficult. I discovered that the former World Chess Champion Tigran Petrosian read "My System" 10 times. "My System" was difficult for him or is it just that chess is difficult, or he thought that anybody needs to master any detail of "My System"? Two books that are easy to read and teach fantastic lessons are "Judgement and Planning in Chess", by the former World Chess Champion Max Euwe and "Chess Giants of Strategy," by grandmaster Neil McDonald.

***I want to conclude by saying that I consider it a mistake to start with chess strategy because chess strategy uses tactics and endgames. One of the most important Soviet schools suggested starting with endgames. There are several reasons behind this.*** From the mathematical perspective, you have a smaller number of pieces in the board, so it is an "easier" problem because the number of possibilities (combinations) is smaller. In addition to that, many tactical and strategical problems switch to an endgame, so if you do not master endgames is difficult to master and even understand tactics and strategy. Also, you will have a great tactical "baptism" with the study of endgames because tactics are required to master endgames. If you would like to know the best endgame books it is better that you post a new question.

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Tags: opening, learning, books, reference-request
---


# Question
Title: What determines length of stockfish 'pv'?
Normally the length (sequence of moves) of what stockfish info prints out as 'pv' matches the search depth, but sometimes it doesn't. When determines its length?

# Answer
I'm not an expert on this, but my understanding is that every now and then as Stockfish searches there will be a so-called "fail high" or "fail low" which forces a re-search. Under these situations Stockfish might not know what the best PV is, but it does know the best move it has found is. That is when it outputs a 1-move PV.

See also aspiration windows on the Chessprogramming Wiki.
> 1 votes

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Tags: stockfish
---


# Question
Title: Why does stockfish give "-28.8" as the evaluation number for this position?
```
[FEN "5K2/8/5k2/5b2/6b1/5b1b/4b1b1/7b w - - 0 1"]

```

This game is an immediate draw by insufficient material (**Doesn't Stockfish know this?**). I am wondering what the reason behind the score "-28.8" is. Even -21 makes more sense to me than -28.8 since each bishop is worth 3 points.

# Answer
> 11 votes
Computer programs are great at performing the specific tasks they've been designed for and useless for anything else. Chess engines are no different. It's just not worth it to design an engine so that it can manage these sort of edge cases.

As far as the engine can calculate, Black has a huge material advatange and after the sequences of moves it can see, if keeps that advantage. In the overwhelming majority of chess positions, the correct way to interpret this fact is that Black has a much better position.

Given enough time and computing power, Stockfish would realize there's no way to deliver checkmate within the next 50 moves, but keep in mind that computers don't have our human intuitions. All they can do is perform a search on the move tree and apply an evaluation function to each of the relevant positions. It can't think in terms of "all my bishops are on light squares, so 7 bishops are effectively the same as just 1".

As for why -28 and not -21 or any other number, well, from a certain point on all evaluations are pretty much the same. If you see -7, -15 or -60 that just means "I think Black is winning but I can't find a specific line that ends in checkmate". Evaluation functions are designed to find nouance in positions that are close to equality, but not so much when we have unbalances as big as this one. Either way a bishop being worth 3 points is just a heuristic for human beginners, not a rule engines would take seriously.

# Answer
> 4 votes
Chess engines are made for regular chess playing not for solving unexpected chess problems that have no very little relevance to chess strength. In fact, an engine that is able to understand an endgame pattern like this would play weaker chess because some CPU cycles would have been wasted on counting the number of bishops on the same colour.

There is no reason for Stockfish to incorporate an endgame knowledge like this. Stockfish could simply play until the fifty-move draw while showing "-28.8" evaluation scores. There's no harm - playing more moves is a draw, stopping immediately is also a draw.

---
Tags: engines, stockfish, draw, bishops, bishop-endgame
---


# Question
Title: Is your actual Elo rank integer-based or decimal-based?
I'm sure that the *published* rankings are reported rounded to the nearest integer!

But *for the purposes of the calculation of the next rankings* are the Elo ranks of GMs considered to *actually be* those integers, or does the managing body track their Elo score to one or more decimal places.

The answer is relevant to my next question (will link after posted)

# Answer
> 1 votes
As you can see from Nakamura's rating calculations for the 2022 GCT Saint Louis Rapid and Blitz - Rapid when he lost 47.80 rating points FIDE uses floating point arithmetic for it's calculations rather than integer. This is not because GMs are special it is because it is the obvious common-sense way of doing things and is done for *all* ratings for *all* players.

# Answer
> 1 votes
Elo ratings are calculated allowing changes with decimals to occur after each game. However at the end of the month all Elos get rounded to the nearest integer.

Imagine Player A has a rating of 2000 and plays two tournaments this month gaining 7.4 Elo points in each. On January 1st, his rating of 2014.8 will turn into 2015 (and that's the number that will be used in all future calculations)

On the contrary, if the same player with a starting Elo of 2000 played one tournament in December and the other one in January, he'd make it to 2007 by January 1st and then to 2014 by February 1st.

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Tags: rating, elo
---


title: Should I switch to a different opening?

text:
# Question
Title: Should I switch to a different opening?
I have been using the queen's pawn game, Chigorin variation ever since I started chess. I am in my school's chess club now and my teacher tells me to use the queen's gambit instead. I know that the engine does not like the Chigorin variation, but I believe I am quite good at it.

What are the arguments for and against changing my opening?

# Answer
> I am in my school's chess club now and my teacher tells me to use the queen's gambit instead

The fact that you are in your school's chess club changes the answer somewhat. It means you are young and still learning.

You have already invested work over time to get to know the Chigorin. You know the opening moves, you know the middlegame plans, you are familiar with the positions that arise. It is a sound opening (so not like the Grob). That means that you shouldn't abandon it for the Queen's Gambit.

As you are young and still learning it is worth your while to also learn the Queen's Gambit. The ideas and plans are different to the Chigorin but it is a useful opening to know and the different plans will expose you to new ideas for you which will help you improve overall.

So, don't switch completely, but do learn the new opening and play it regularly. At the same time go back some of the time to your Chigorin. It will make you a more difficult opponent. Your opponents won't know for sure what you are going to play and will find it harder to prepare against you.
> 10 votes

---
Tags: opening, learning, queens-gambit
---


# Question
Title: Why can't I move this knight on e2? Why does the engine suggest moving the knight on b1?
Why can't I move the knight on e2? Why does the engine suggest moving the knight on b1?

# Answer
The reason you cannot move the knight is because it is blocking the check from the queen on e7. This is known as a "pin". Since it is illegal to make a move that puts yourself in check, the knight cannot move.

Even if that e7 queen was not there, moving the knight would *also* allow the bishop on f3 to take your queen on d1. This would also be called a "pin", because even if the knight could *legally* move, it would lose material if it did.

The other answers are suggesting playing the b1 knight to d2. I think this would be a mistake, since that would block your queen from defending d4, allowing Black to play Nxd4 (which would win a pawn, attack the knight on e2 one more time, and also protect Black's bishop on f3.) And if you actually take the f3 bishop with that knight, you end up losing your g1 rook to a fork, as I show in the diagram. Nc3, which develops a piece and defends the e2 knight, is probably better.

Rg3 is also an interesting idea. It attacks your opponent's bishop and sets up a threat of Re3, which would turn the tables and pin your opponent's queen to their king! Black can play Be4 to block that threat, but that also blocks the pin on your knight.

```
[FEN "r3kbnr/ppp1qppp/2n5/3p4/3P1P2/5b2/PPP1N2P/RNBQKBR1 w Qkq - 0 1"]

1.Nc3 (1.Nd2 Nxd4 2.Nxf3 Nxf3+ 3.Kf2 Nxg1 4.Kxg1) (1.Rg3 Be4 (1...Bh5?? 2.Re3!) )

```
> 23 votes

# Answer
Welcome to Chess Stack Exchange! You cannot move the knight because it's currently pinned to your King. In simple words, if you move your knight on e1 then your King is in danger because of the black Queen on e7.

You are suggested to move your knight from b1 to d2 because that would help in developing your pieces and would also attack your opponent's bishop.
> 9 votes

# Answer
Moving your e2 knight is illegal because it is in a position we call a "pin" It happens when your piece(in this case, your knight) is the only piece blocking the opponent's attacking piece(in this case, the queen) from checking your king. That prevents your knight from moving it, therefore pinning it.

And you are recommended to move your b1 knight because you attack the bishop this way. At the same time, this move helps develop your pieces. Hope I was helpful!
> 0 votes

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Tags: online-chess
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# Question
Title: pgn-extract: specify variation name when using --splitvariants flag
I'm using the --splitvariants flag to generate cards for anki, my problem is, how can i identify which line i'm playing? I though pgn-extract would have something like this, what i need is some way to append the variation name at the end of the line.

Please ignore the `false` keyword, what i need is to append a `;$VariantName` at the end of each line

# Answer
> 1 votes
For @kentdjb and anyone interesed I solved my issue by doing the following:

First I downloaded an eco.pgn containing the names of openings and variations. You can find it here

Then I created an `args` file containing the following options:

```
:-C
:-e
:-w1000
:--minmoves 2
:-ofull-vienna.pgn
:--splitvariants
:--detag Event
:--detag Site
:--detag Date
:--detag White
:--detag Black
:--detag Result
:--detag ECO
:--detag Round
:--detag UTCDate
:--detag UTCTime
:--detag Annotator
:--detag Variant

```

Finally I ran the following command in my two pgn files containing vienna lines:

`$ pgn-extract {vienna-foobar1,vienna-foobar2}.pgn -Aargs` the output will throw something like this:

```
[Opening "Vienna gambit"]
[Variation "Paulsen attack"]

1. e4 e5 2. Nc3 Nf6 3. f4 d5 4. fxe5 Nxe4 5. Qf3 Nxc3 6. bxc3 Be7 7. d4 O-O 8. Bd3 Be6 9. Ne2 c5 10. O-O Nc6 11. Be3 *
1. e4 e5 2. Nc3 Nc6 3. Bc4 Bc5 4. Qg4 Qf6 5. Nd5 Qxf2+ 6. Kd1 Kf8 7. Nh3 h5 8. Qg5 f6 9. Qg6 Rh6 10. Ne7 *
1. e4 e5 2. Nc3 Nc6 3. Bc4 d6 4. d3 *
...

```

To convert this lines to anki cards I just use a vim macro to insert the `$Opening` and the `$Variation` at the end of each line.

Hope this is useful

---
Tags: pgn
---


# Question
Title: Are bishops and knights more powerful than rooks on an 8x8x8 board given these rules?
Let's say that on an 8x8x8 board rooks can move any number of spaces, only moving through one dimension at a time. Bishops move the same number of spaces in exactly 2 dimensions at a time. Knights move 2 spaces in 1 dimension and 1 space in another dimension. Kings move 1 square in any direction, meaning that in the center of the board a king controls 26 spaces.

I noticed that in 2 dimensions rooks, and bishops have the same number of directions they can move in, but in 3 dimensions with the above way to generalize the movement of the pieces to 3 dimensions, there are twice as many directions to move for the bishops as there are for the rooks. Also the ratio between the number of spaces bishops control to the number of spaces knights control is the same in 2 dimensions and 3 dimensions. A King and Rook is not enough to checkmate a king in 3 dimensions as the lone king can always use the 3rd dimension to escape any check from the rook. In 2 dimensions a knight takes 4 moves to get to the spaces that are 2 spaces diagonally away, but in 3 dimensions because of the extra degree of freedom a knight only takes 2 moves to get to the spaces 2 spaces diagonally away from it. This makes it seem like Bishops and Knights might be more powerful than rooks, and that knights might be more powerful than bishops as they don't have all the same blindspots they do in 2 dimensions.

So how powerful are Rooks, Bishops, and Knights on an 8x8x8 board compared to each other?

# Answer
I would say yes, the bishops and knights would probably be slightly stronger than the rooks.

Let's start out with a look at how many squares the pieces cover on an empty board:

Traditional chess:

* 64 squares on board
* Rook: 14 squares
* Bishop: 7-13 squares
* Knight: 2-8 squares
* King: 3-8 squares

Variant:

* 512 squares on board
* Rook: 21 squares
* Bishop: 21-39 squares
* Knight: 6-24 squares
* King: 6-26 squares

If we were to simply multiply based on square control, if knight-bishop-rook used to be 3 - 3.25 - 5, it would now be 9 - 9.75 - 7.5. If we were to then divide by 3 to take into account the increased power of the king, it would be 3 - 3.25 - 2.5. So by this metric the rook would indeed be weaker.

The knight's "blind spots" would be reduced. It would still, however, take 3 turns to get to an adjacent square. A knight in the corner could reach any square in 8 moves instead of 6 due to the bigger board; the loss of that blind spot might be offset by the increased number of squares not close to the knight. And a knight would still be unable to gain or lose a tempo.

You don't mention the pawn rules; they would probably have an impact on how easily a knight outpost could be created. Once created, it seems like it would be more difficult to keep an enemy knight out. A well-placed knight with 24 possible squares it could go to would seem fairly dangerous; a knight on the 4th level could threaten at least some squares in the 2nd through 6th levels directly, and could threaten forks in some places in *all* the levels.

The bishop would be much more difficult to trap or restrict. A bishop isn't very "bad" if it can just go over or under the pawns, after all. Visualizing their new movement might take some getting used to. They would still be restricted to one color, of course, which does limit their power just like it does in regular chess.

A bishop can't really dominate a knight on the side of the board like it can in 2d chess. The bishop *can* prevent the knight from going in a particular direction for *one* turn, but cannot maintain this.

A pair of bishops would no longer be able to keep an enemy king on the side of the board by themselves. Bishops have always, of course, had a blind spot directly in front of them, but that could be protected by the other bishop in the pair. But now they gain additional blind spots in the squares which are diagonal in all 3 dimensions. There is a 2 bishop + king helpmate available at the corner of the board, but I'm guessing it can't be forced.

Bishops would gain the ability to break a pin while still protecting the pinned piece. If, for example, a bishop was on c1 protecting a pawn on d2 from an enemy bishop on h6, the d2 pawn would be pinned - but the c1 bishop could move to d1 on an adjacent level, which still protects the pawn but breaks the pin. Rooks would not gain such an ability; a rook on d1 with a pawn on d2 and an enemy rook on d8 does not have a square it can get to in one move where it could break the pin while still protecting the pawn. (Kings and queens already have this ability in 2d chess, and it's impossible for that situation to come up with a knight in either game; there's no way for a knight to be behind a pin while directly protecting the pinned piece.)

Rooks would lose their property of being able to reach any square in two moves on an open board; now it would take three. And, of course, a rook can no longer give checkmate with only the king to help. Back rank checkmate threats would also seem to be reduced if the enemy king can escape via the other dimension. But they are still a long-range piece which can perform pins and forks.
> 3 votes

---
Tags: chess-variants, knights, bishops, rooks, point-value
---


title: Question about a chessboard's material

text:
# Question
Title: Question about a chessboard's material
https://kingchesssets.com/products/black-anigre-wooden-chess-board-24-inches

I found this chess board made of a certain type of wood. What exactly is Black Anigre?

# Answer
> 3 votes
> so what is black anigre?

If you take the trouble to read what it says at the link you gave then you get this answer:

> The chess board is made of Black Anigre. Anigre is an African hardwood commonly used for plywood, interior furniture, cabinetry, and high-end millwork applications.

---
Tags: chessboards, identify-this
---


# Question
Title: Help understanding lichess puzzle 274165037
Link to puzzle: https://lichess.org/training/274165037

I got the correct solution first try, but I don't understand what it accomplishes. Seems the king can escape via f2 and rook h1 should deal with the pawn push

```
[Title "Lichess puzzle"]
[fen "2kr3r/ppq2pp1/3b4/2p1n1P1/2P1N2p/P2P3K/1PQ1N3/R1B2R2 b - - 0 1"]

1...Qd7+ 2. Kg2 Qg4+

```

What am I missing?

# Answer
Rh1 in response to h3 by black just loses the rook after Qg2+. White has to move a knight to g3 to try and stop the pawn queening but then black starts a king hunt with Qf3+ which leads to mate.

```
[Title "Lichess puzzle"]
[fen "2kr3r/ppq2pp1/3b4/2p1n1P1/2P1N2p/P2P3K/1PQ1N3/R1B2R2 b - - 0 1"]

1...Qd7+ 2. Kg2 Qg4+ 3. Kf2 h3 4. Rh1 (4. N2g3 Qf3+ 5. Ke1 Nxd3+ 6. Kd2 Bf4+ 7. Kc3 Nf2+ 8. Be3 Qxe3 9. Qd3 Qxd3#) Qg2+

```
> 4 votes

# Answer
This is a simple puzzle that wants you to correctly steer into the most forcing line, seizing an attack. It is not a study that wants you to find a nice, unique solution down every line.

**What it does say**:

Your opponent has not realized they had to play d4 in order to open the diagonal for their queen to gain access to f5.

Do you realize you have a winning position at hand?

Do you realize you have to start with Qd7+ immediately?

**What it doesn't say**:

Can you force a way to always at least win white's queen for a knight? (Hint: white has to take black's knight with their queen to avoid checkmate!)
> 0 votes

---
Tags: puzzles
---


# Question
Title: Example of "lowerbound" and "upperbound" in the UCI protocol
I am having trouble understanding how "upperbound\` and "lowerbound" come into play in the UCI protocol.

The spec says:

> * lowerbound: the score is just a lower bound.
> * upperbound: the score is just an upper bound.

For example, I see Stockfish using it like this.

```
info depth 22 seldepth 27 multipv 1 score cp 27 upperbound nodes 2567224

```

I kind of understand that it is related to the "cp." But I don't really know how. Could someone help me clarify this? It would be best if you used an example.

# Answer
It is a type of info which an engine can produce *during* the search, mainly targeted at developers. It means that at that depth stockfish (believes to) have established, that the score it at least 27 centipawns. Stockfish uses some variation of aspiration search and this variant can produce such intermediate results. An engine like Leela Zero uses a different algorithm and therefore never bother the users with such infos.

If you are only interested in chess contents, you can completely ignore that output.
> 2 votes

# Answer
Another search algorithm that produces lower and upper bounds is MTD. It is basically a binary search that narrows in on the true value.
> 0 votes

---
Tags: engines, uci
---


# Question
Title: What is the QGD set-up with queen-side fianchetto and c4 called?
In a recent blitz game, my opponent played a setup that looked like this:

```
[fen "rnbqkbnr/pppppppp/8/8/2PP4/1P2P3/PB3PPP/RN1QKBNR b - - 0 1"]

```

I can't quite remember where the knights and light-squared bishop went, I guess Nf3, Nd2/c3 and Bd3. I played normal development with d5, e6, Nf6, Nd7, Be7.

Since it was a strong player, I'm assuming this setup or system has a name, but I've unable to find it. Unfortunately I can't recall the move order. What is it called?

# Answer
That looks very like the Colle-Zukertort except the c pawn usually doesn't go to c4 quite that early. Normally white develops the kingside pieces and castles first.

Here, for instance is part of Linqvist-Pihlajasalo, Jyvaskyla 1996

```
[Title "Linqvist-Pihlajasalo, Jyvaskyla 1996"]
[fen ""]
[Startply "15"]

1. d4 d5 2.Nf3 Nf6 3. e3 e6 4. Bd3 c5 5. b3 Be7 6. O-O O-O 7. Bb2 b6 8. c4

```
> 9 votes

---
Tags: opening
---


# Question
Title: How do you program a chess bot with specific style?
There are these cute chess.com bots against which you can play, which not only have different strengths but supposedly different playing styles.

I haven't researched exactly how "limiting engine strength" is done, but since other programs do it I can look it up.

But what is more interesting is how to program a bot that likes being aggressive or passive, that is dynamic or solid, etc.

Could you describe how to measure whether a move is to the liking of a player with a certain style? What is that measure?

# Answer
## Evaluation Function

That measure is called the **evaluation function**. Each bot can have a different evaluation function depending on how you want it to behave. Will it favour dynamic play or will it play positionally and emphasize pawn structure? If your bot uses a **classical evaluation** function, these features can be weighted/tuned according to your needs. Here are some examples of features commonly used in classical evaluation functions:

* Material
* Pawn Structure
* Evaluation of Pieces (e.g. good vs bad minor piece)
* Mobility
* Center Control
* King Safety
* Space

For example, if you want to create a bot that plays aggressively, you might try to make it value material and pawn structure less and mobility and king safety more. You can visit the Chessprogramming Wiki to see more examples and how such features could be measured and implemented. You can also come up with own features such as "trappiness", be creative! If you want it to make hyper-aggressive pawn thrusts, you could for example reward moves like g4 in the early game phase.

I suggest you use Stockfish, for anything not related to the evaluation (a chess engine also needs a search) and use your own evaluation function, which should be pretty easy to do.

This has already been done, see the SimpleEval bot. Your evaluation function does not even need to be extremely complex to reach acceptable playing strength, as you can see in that extreme example. Here is the bot's source code.

You can also try to use a **neural network evaluation** function. There is research on how to make neural network evals play "human moves" rather than "computer moves", the result being the Maia-bots. You can try a similar approach to what they write in the paper, but instead of learning on random games learn on games of specific players (e.g. attacking players). This is easier said than done, however, as your training set will probably be extremely small compared to what Maia had to train. Here are some ideas on how you might make it work:

* learn on self-play or human games, but weigh the games of the players you want to mimic much more heavily
* try transfer learning
* do some original research

That being said, I think that it should be easiest to use a classical evaluation as it is much easier and cheaper to test and tweak.

If you do not want to write your own evaluation function, you can also take an existing one and tweak it. You might already get interesting results by tweaking the parameters of existing engines, e.g. contempt (here is the wiki entry). The contempt factor will influence how much the engine tries to avoid (or seek) draws, therefore playing more riskily and aggressively (or solidly). Pair that with an opening book (see next section) - and tada - you already have a bot playing in a certain style!

## Opening book

In order to help the bot to behave the way you intend, it is very advisable to give it an opening repertoire that suits its intended play-style.

This is done on chess.com to create bots of famous players.

If you prescribe your bot to play the sharpest variations of the Sicilian, it will be forced to play aggressively.

This will be a head start for your bot and I expect the opening book to make your task much easier.
> 5 votes

---
Tags: engines, programming, style
---


# Question
Title: Could you raise your score arbitarily high by only playing against much weaker opponents?
*Obviously the community would accept or acknowledge such a hack ... but mathematically would it work, or does the Elo system have something to prevent this?*

My impression is that, very roughly speaking each time you play someone, your Elo goes up or down depending on whether you win. And how *much* it goes up or down depends on the disparity between your previous rating and your opponents.

* If you beat someone who was better than you it goes up a bunch.
* If you beat someone who was a little bit worse than you, it goes up a little.
* If you beat someone who was *very* much worse than you, it goes up a tiny amount.

But I assume that even if you play people who were ridiculously worse than you ... is still goes up *a bit*?

So could you hack your "rating" by playing tons of games against people who are much worse than you ... such that you'll *never* lose, and your rating will keep going up and up, even though you're not getting any better?

# Answer
> 2 votes
> So could you hack your "rating" by playing tons of games against people who are much worse than you ... such that you'll never lose

No. If you play enough games you will lose some and draw some and every draw will lose a ton of points and a loss will lose even more. The ratings calculation tables are based on statistics so that expected ratings gains and losses correspond to the probabilities of players with the given rating difference winning, drawing or losing.

See also this related question.

# Answer
> 1 votes
1. Rating calculations are done while keeping a few things in mind to avoid these kinds of hacks. If you play a very low-rated player for a number of games then there'll be a point there'll be no rating gain. Just zero points for a win
2. There are chances that you might end up losing/drawing a game as your opponent will understand your game plan/strategy. This will cost you a lot of ratings.
3. If you play weak players consistently then your game will not improve and may even become worse.

# Answer
> 0 votes
Yes, with a "pure" Elo system, you could, *theoretically*, increase your Elo arbitrarily large. There are three caveats:

1. Each organization uses a different versions of the Elo system, and they may very well have a modification, such as having a cutoff after which you don't receive any Elo gain.
2. While *mathematically*, there is no upper limit, in practice there's a limit to how many points a person could get before they died of old age.
3. Winning 100% of the time, not just 99.99%, isn't necessarily possible. I'm reminded of "Man from the South" by Roald Dahl https://en.wikipedia.org/wiki/Man\_from\_the\_South :

> While vacationing at a resort in Jamaica, the narrator encounters an elderly South American man named Carlos. They are soon joined by a young American naval cadet, who boasts about the reliability of his cigarette lighter. Carlos offers to bet his Cadillac against the American's left little finger that the American cannot ignite the lighter ten times in a row.

The tension comes from the fact that no matter how easy something is, can you really be sure that you won't mess it up somehow?

---
Tags: rating, elo
---


title: Where to play online Bughouse Chess

text:
# Question
Title: Where to play online Bughouse Chess
As far as I can tell the main sites I use like chess.com, lichess.com, and chess24.com do not support bughouse. Is there a popular place to play online somewhere? It would also like to have the ability to play on iOS. Thanks.

# Answer
use one of the fics interfaces. Freechess.org
> 2 votes

# Answer
Now you can play bughouse at Chess.com (for free). You can read this article to get help.
> 12 votes

# Answer
You can play on online1.eu where is possible to play slower bughouse also. There You play using web browser, so You can play from any PC, notebook, tablet, iPod etc. with any operating system like windows, linux, android, or iOS.
> 1 votes

# Answer
FICS(freechess.org) and ICC(chessclub.com)
> 1 votes

# Answer
Android mobile app for bughouse online game with your friends: https://play.google.com/store/apps/details?id=ru.mail.park.bughouse
> 0 votes

# Answer
chess.com has bughouse; it works quite well.

I know lichess is working on it.
> 0 votes

# Answer
You can use new small specialized bughouse chess server which has unique lag double board compensator options on onlinea.org , actually runned node http://onlinea.eu
> 0 votes

---
Tags: online-chess, bughouse
---


# Question
Title: When and why is it good to deny the development of White's dark squared bishop in the Caro-Kann exchange variation?
In the position after

```
[FEN ""]
[startlfipped "10"]
[Startply "10"]

1. e4 c6 2. Nf3 d5 3. exd5 cxd5 4. d4 Nc6 5. Bd3 Bg4 6. O-O? Bxf3! (6...Qc7? 7. c3) 7. Qxf3 Nxe4

```

White has played inaccurately because Black can get a better version of the mainline of the exchange variation, as White cannot easily develop the bishop to f4 after 6. c3 and 6. ..Qc7 (this is the engine recommendation and the recommendation in my book).

However, when White instead plays 6. O-O, the engine thinks that Black is already better (-0.6) after taking on f3 (6. ..Bxf3). 6. ..Qc7 however is a sizeable mistake that not only throws away the advantage but even puts Black on the backfoot who then already has a pretty worrisome position (0.8).

I don't understand why

1. 6. O-O is so bad for White and why ..Bxf3 is so strong in response
2. 6. ..Qc7 is such a massive mistake, even though it still denies the natural development of the dark-squared bishop and is the best move when White plays 6. c3.

How could this be explained?

# Answer
> 4 votes
I add another answer since the crucial point hasn't been addressed, methinks. Indeed, after 6...Qc7 7.c3 it's a simple transpose and any decent algorithm shouldn't depend on move order to the position.

But White plays 7.h3. Black now can't win d4 (d5 hangs as well) after Bxf3, so this merely cedes the bishop pair. And if 7...Bh5, 8.g4 Bg6 9.c4. (Computer are never afraid. Unsurprisingly, no human - on Lichess - ever tried this. Even I wouldn't. Evaluation is a slight advantage for White.)

# Answer
> 4 votes
The 6...Bxf3 tactic wins the d4 pawn by removing its defender. Sure, it gives up the two bishops to do so, and that's the reason why black's not a full point up in evaluation. But that's not enough compensation for even a human white, and the computer cares about it even less.

After 6... Qc7 the tactic no longer works (The d5 pawn is also hanging after ...Bxf3 Qxf3, and ...Nxc2 won't work if it doesn't come with check because the black king is exposed) and so white can forgo c3 and ends up having gained the tempo of castling in exchange, making this better than the other line.

# Answer
> 2 votes
In case anybody's wondering why after 6 0-0? Black doesn't keep the Bishop pair and play Nxd4 directly, which may seem even better: That falls into a trap familiar (with colors reversed) from the QGD, losing a piece to 7 Nxd4! because after Bxd1 8 Bb5+ Qd7 9 Bxd7+ and 10 Rxd1 (or first 9 Rxd1) White's still ahead N for P and should win the ending easily.

# Answer
> 1 votes
After 6.O-O Bxf3 7.Qxf3, Black plays Nxd4 and is up a central pawn. That's enough for the evaluations to flip that much.

---
Tags: opening, caro-kann, development, prophylaxis
---


# Question
Title: How to improve at chess by analyzing one's own games?
Analyzing one's own games can be a useful tool for improving at chess, as it allows players to identify their mistakes and learn from them. However, it can be challenging to accurately assess one's own play and find the best way to improve.

What are some effective techniques for analyzing one's own chess games? How can players avoid the pitfalls of self-analysis, such as being too harsh or lenient on oneself, or overlooking important mistakes? Is it better to analyze one's own games immediately after playing, or is it better to take some time to let the emotions of the game dissipate first?

# Answer
> How can players avoid the pitfalls of self-analysis, such as being too harsh or lenient on oneself, or overlooking important mistakes?

Those are not the major pitfalls of self-analysis. That is using a computer instead of your own brain. There *is* a place for the engine but it is right at the end of the process.

Here is the ideal, full process:

1. The day after the game start the process. This allows time for the elation/satisfaction/despair (delete as appropriate according to the result) to die down but the game and your thoughts during the game are still fresh enough to remember. If you leave it too long then narratives you tell yourself to make yourself feel better will start to displace what you were really thinking at the time. Get a clean sheet of paper and a pen/pencil because you are going to record the process. That is a lot more permanent than just taking place in your head. Start by trying to identify the key points in the game. These are the points in the game where the evaluation changed or key decisions were made. Analyse the moves around these key points, writing down your analysis, current thoughts and remembered thoughts from the game.
2. Give a copy of the game to a chess-buddy. This could be your coach, if you have one, it could be a club mate at a similar level to you. Ask them to go through the same analysis process and write their thoughts down.
3. Meet up with your chess buddy and compare and discuss your analyses. Both the stuff you agree on and the stuff you disagree on are important learning points (for both of you).
4. Almost finally run the game through an engine to see what it thinks of the game and your analysis and your chess buddy's analysis.
5. Finally reassess to see what you need to learn from the game and the different analyses of the game.
> 6 votes

# Answer
When playing in a tournament, it is generally not possible to analyse one's games immediately afterward. There simply isn't time. Still, it should be done just after the tournament, when you might still be able to remember what you were thinking. "Well, I considered Bxb5 here, but did not like ...Qe5+. Now I see I could have played...." You get the idea.

**Do not use a computer.**

I cannot stress that enough. You will not learn to look for better moves, and you will not look for your mistakes. You will just let the computer do all the work for you, and you will learn nothing. Only after you have done a *thorough* analysis yourself should you submit the game to the computer. And put your analysis in, too, to see whether you missed moves in your analysis.

Classify the moves you missed. When one is a novice, they will be simple things such as hanging pieces and missed checks. Then they will move to missed forks, undefended (vulnerable) pieces, and things of that sort. At advanced levels, it will be moves that influence center control, piece mobility, and pawn structure. And it may just be the loss of a tempo that is the difference between a win (or loss) and a draw. Finding such mistakes is, of course, more difficult. When you have a bunch of those, see what types of moves you are most likely to miss, and look for them in future games.

**Get a coach**

If you can, get a coach to review your analysis. He may or may not be of any more use than the computer, but he will provide *accountability*.
> 2 votes

---
Tags: analysis, learning
---


# Question
Title: How to effectively use the queen in chess opening strategy?
The queen is the most powerful piece in chess, with the ability to move in any direction and threaten a wide range of squares. However, it can be challenging to effectively use the queen in the opening, as it is also a target for the opponent's pieces and can be vulnerable to attack.

What are some key considerations for using the queen in chess strategy in the opening phase of the game? How can players use the queen to control the center of the board or to create weaknesses in their opponent's position? Are there any specific tactics or combinations that are especially useful for the queen, or that should be avoided in certain situations?

Any tips or examples on how to effectively use the queen in chess would be greatly appreciated. Thank you!

# Answer
> 6 votes
### Example 1: French defense: Qb6

A queen on b6 puts pressure both on the b2 pawn (sometimes threatening to take when the pawn becomes weak after the bishop develops) and more importantly, the central d4 pawn.

```
[FEN ""]
1. e4 e6 2. d4 d5 3. e5 c5 4. c3 Nc6 5. Nf3 Qb6

```

Putting pressure on White's center is a main strategy of the French and Caro-Kann advance variations, and Qb6 an important move to that end.

In the Poisoned Pawn Variation of the Najdorf Sicilian, Black often takes the "poisoned" b2 pawn. This also happens in other openings, e.g. a line in the Caro-Kann Advance, Short variation. When you take on b2, you need to make sure the queen does not get trapped!

### Example 2: Caro-Kann defense: Qa6

```
  [fen ""]
  1. e4 c6 2. d4 d5 3. e5 Bf5 4. h4 h5 5. Bg5 Qb6 6. Bd3 Bxd3 7. Qxd3 Qa6

```

In many lines of the Caro-Kann defense (and the French defense), the queen gets developed to b6 in order to put pressure on the White center. In this example however, I'd like to show you the move Qa6, which is also a very common theme (sometimes the queen also comes from a5 after giving a check). The goal of Qa6 is to trade off the queens.

### Example 3: Qa5+ tactics

Qa5+ is a common tactic/resource, often picking up something on the 5th rank. There are countless examples, take this one as an illustration. The move Qa5 is also common in a lot of other openings (e.g. Grünfeld defense).

```
 [FEN ""]
 1. e4 c5 2. Nf3 e6 3. d4 cxd4 4. Nxd4 Nf6 5. e5?? Qa5+

```

### Example 4: Taimanov Sicilian: Qc7

```
[FEN ""]
1. e4 c5 2. Nf3 e6 3. d4 cxd4 4. Nxd4 Nc6 5. Nc3 Qc7

```

Here, the queen gets developed early to c7. One idea of the move is to control the center (e5).

**While I hope that these examples show, how the queen is used in the opening, I strongly encourage you to remember that generally, you shouldn't use your queen too early in the game.**

EDIT: Of course, the same ideas apply with colours reversed, e.g. Qb3 or Qc7 in many Queen's Pawn openings. There is also Qh5 when Black has not castled, attacking on the h5-e8 diagonal (if the f-pawn has moved, with check - this is a reason why moving the f-pawn in the opening is very often a bad idea).

---
Tags: opening, strategy, queens
---


# Question
Title: Should FIDE introduce a minimum rating for arbiters?
As it stands right now, FIDE does not have any minimum Elo rating requirement for arbiters. In fact, there's no test to check whether one can play chess or not before being awarded a FIDE arbiter-related titles.

It seems clear to me that a minimum rating is required for an arbiter to do their job properly but what are the arguments for and against requiring a minimum over-the-board rating for arbiters?

# Answer
In the pre-2014 FIDE Laws of Chess article 10 said this:

> **Article 10: Quickplay Finish**
>
> 10.1 A ‘quickplay finish’ is the phase of a game when all the (remaining) moves must be made in a limited time.
>
> 10.2 If the player, having the move, has less than two minutes left on his clock, he may claim a draw before his flag falls. He shall summon the arbiter and may stop the clocks. (See Article 6.12.b)
>
> a. If the arbiter agrees the opponent is making no effort to win the game by normal means, or that it is not possible to win by normal means, then he shall declare the game drawn. Otherwise he shall postpone his decision or reject the claim.
>
> b. If the arbiter postpones his decision, the opponent may be awarded two extra minutes and the game shall continue, if possible in the presence of an arbiter. The arbiter shall declare the final result later in the game or as soon as possible after a flag has fallen. He shall declare the game drawn if he agrees that the final position cannot be won by normal means, or that the opponent was not making sufficient attempts to win by normal means.
>
> c. If the arbiter has rejected the claim, the opponent shall be awarded two extra minutes time.
>
> d. The decision of the arbiter shall be final relating to (a), (b) and (c).

In the 2014 to 2017 FIDE Laws of Chess this moved to Appendix G and was expanded.

> **Appendix G. Quickplay Finishes**
>
> G.1 A ‘quickplay finish’ is the phase of a game when all the remaining moves must be completed in a finite time.
>
> G.2 **Before the start of an event it shall be announced whether this Appendix shall apply or not.**
>
> G.3. This Appendix shall only apply to standard play and rapidplay games without increment and not to blitz games.
>
> G.4 If the player having the move has less than two minutes left on his clock, he may request that a time delay or cumulative time of an extra five seconds be introduced for both players, if possible. This constitutes the offer of a draw. If refused, and the arbiter agrees to the request, the clocks shall then be set with the extra time; the opponent shall be awarded two extra minutes and the game shall continue.
>
> G.5 If Article G.4 does not apply and the player having the move has less than two minutes left on his clock, he may claim a draw before his flag falls. He shall summon the arbiter and may stop the chessclock (see Article 6.12 b). He may claim on the basis that his opponent cannot win by normal means, and/or that his opponent has been making no effort to win by normal means
>
> If the arbiter agrees that the opponent cannot win by normal means, or that the opponent has been making no effort to win the game by normal means, he shall declare the game drawn. Otherwise he shall postpone his decision or reject the claim. If the arbiter postpones his decision, the opponent may be awarded two extra minutes and the game shall continue, if possible, in the presence of an arbiter. The arbiter shall declare the final result later in the game or as soon as possible after the flag of either player has fallen. He shall declare the game drawn if he agrees that the opponent of the player whose flag has fallen cannot win by normal means, or that he was not making sufficient attempts to win by normal means. If the arbiter has rejected the claim, the opponent shall be awarded two extra minutes.

The movement from the main articles to an appendix is significant and this trend continued in 2017 and the latest version of the rules. In the latest version of the FIDE Laws of Chess it has moved to a new section "Guidelines".

It is not too dissimilar to the 2014-2017 version so I won't repeat it.

There are two key points:

1. The arbiter requires real chess skill to fulfil his/her function. "The opponent cannot win by normal means" is not a straightforward decision to make. A minimum rating for arbiters would make a lot of sense. I believe such a suggestion has been made at the level of the Arbiters Commission and I will try and find a reference. I believe a rating somewhere in the region of 1700 to 1900 has been suggested and no doubt argued over.
2. The clear trend for this rule is deprecation and elimination. The next revision of the rules is due in 2021. I think it is a better than even money bet that this rule (along with adjournments in Guidelines 1) goes away. If this happens the argument for a minimum rating for arbiters is much diminished but currently I don't see how an arbiter with only a weak grasp of the game could adjudicate such positions.
> 7 votes

# Answer
No. A good arbiter needs to know the Laws of Chess, but that's about it. There's no need to refer to tactics or openings or strategy when you're arbitering. After all, the days of adjudication are over.

I've heard that there are a lot of arbiters with titles that aren't good arbiters, but that wouldn't be solved with imposing a minimum rating. In fact, such a minimum would end up excluding good arbiters who don't even play (my country's only active International Arbiter doesn't compete at all, she has no rating, but she does a great job at being an arbiter).
> 8 votes

# Answer
As far as I know, one of the best, Carol Jarecki, did not even play chess. https://arbiters.fide.com/news/6256
> 0 votes

---
Tags: rules, fide, rating, arbiters
---


title: Simultaneous tournament games

text:
# Question
Title: Simultaneous tournament games
The status: I just qualified for German DPEM. All "big" tournaments, since a few years, have been collected on the "Schachgipfel". Last year I played very well in the DSenEM (a win in the last round *would* have gained me the title), so I want to play it again. Both tournaments run on the same day, but time-shifted. Starting one, the game might not be ended when the other begins.

The snag: Obviously §E11.3.1 prohibits "playing" two games at the same time. But does it also prohibit that I let my clock run down if necessary in the second game (I'm a lightning fast player, one hour would still be a correspondence game to me :-), end the first and then make my move in the second? (Venue is the same, I just have to switch rooms, so that's a nonissue.) After all, if I don't make my first move, I don't play yet.

The hour I could squeeze out this way *could* make the difference of being able to play both tournaments (I'm a chess freak) - but is it allowed at all?

# Answer
> 2 votes
> But does it also prohibit that I let my clock run down if necessary in the second game (I'm a lightning fast player, one hour would still be a correspondence game to me :-), end the first and then make my move in the second?

There are three FIDE Laws which are relevant:

> 6.7.1 The regulations of an event shall specify a default time in advance. If the default time is not specified, then it is zero. **Any player who arrives at the chessboard after the default time shall lose the game *unless the arbiter decides otherwise***.

and

> 11.2.1
>
> **The ‘playing venue’ is defined as the ‘playing area’, rest rooms, toilets, refreshment area, area set aside for smoking and other places as designated by the arbiter**.
>
> 11.2.2
>
> The playing area is defined as the place where the games of a competition are played.
>
> 11.2.3
>
> **Only with the permission of the arbiter can:**
>
> 11.2.3.1
>
> **a player leave the playing venue**,

and

> 11.3.1
>
> During play the players are forbidden to use any notes, sources of information or advice, or analyse any game on another chessboard.

Your question addresses the second but not the first and third, which are also relevant.

There is no point in turning up 45 minutes late for the second tournament if you were defaulted after 30 minutes.

Solution: talk to the chief arbiter of the second tournament beforehand, explain what you want to do and ideally get their agreement. Worst case is they disagree and you know you have to get to your seat before the 30 minutes (or whatever the default time is) expires.

Ideally the two tournaments are part of some tournament umbrella and the playing areas for both tournaments are each in some joint playing venue. Again you should try and check with the chief arbiters of both tournaments beforehand.

If that is the case then you can go to the second playing area after the start of play, register your presence with the arbiter and your opponent, explain the situation to your opponent, not make a move, go back to playing area one, complete your game and then return to playing area two and start your game there.

A note on a player arriving after the expiry of the default time and the arbiter's decision. When I have been the arbiter in those situations I try and find out what is going on with the late player usually by asking the organizer to try and contact the player to find out what is going on. If the player is just delayed then I ask the present opponent what they want to do in the case that the player exceeds the default time. If they want the point regardless then I default the late player when the time is up. If they prefer to play a game (could be important for norms and tie-breaks, prize money etc.) then I allow the late player to play.

---
Tags: rules
---


# Question
Title: Why is this position -6.2 without a big material difference?
In one of my recent games, I got to the following position, Black to play:

```
[FEN "2rr2k1/1q2bppp/p3pn2/np1p4/4PQ2/P1N2P1P/BP1R2P1/2R1B1K1 b - - 1 21"]

```

While playing the game, I analyzed d4 and it looked good even after Ne2 saving the rook but I considered it to be too risky to play and decided to play a safer move, dxe4. Stockfish 14+ NNUE gives -6.2 with depth 30. I further analyzed the position with the engine like about 10 moves ahead but couldn't see a material difference other than the existent +1 pawn. I don't understand how is this a **positional** -6.2

Can someone please explain why this is such a winning position for black? Because I couldn't understand the engine moves.

# Answer
> 12 votes
It's "only" -3 with standard LiChess analysis settings, but your point remains. Thing is your "10 moves ahead" (plies or moves?) are *nothing* when it comes to calculation - White's officers are a chicken den after the fox came in, as Germans say. Even the Q is in danger after Nh5, and White either must cede another pawn, or play Bxc4 (giving two dangerous pawns instead of one, and a dead meat Pb2), or let the Pd3 run, or immediately give the exchange after Nc4 (best move, says the engine). I'm quite a strong defender, but after some few more moves I tried it becomes clear what a desaster the White position is - and that even though Black displaces the knight - Nh5 or the seemingly tame Nd7 - in some variants. To see until the inevitable crash is way beyond my horizon even if my instincts already say White is in dire straits.

Fun experiment: Kh1 Qg1 instead of Kg1 Qf4. Black's advantage reduces to -0.5 after d4! So all these random tactics are the "real" reason of White's downfall.

# Answer
> 4 votes
Black is not winning immediately but the -5 to -6 evaluation looks correct to me. Here's why:

After black gets d4-d3 and Nc4, it becomes pretty tricky for white to bring their bishop into the game; hence, they have to exchange it for the knight on c4. Now, you have two connected pawns in white's territory. The plan for black is quite simple now- just bring back the knight to an active square(eg. b3), exchange the bishops, build a queen rook battery(to put pressure on weak pawns), and promote the pawns.

Of course, it's not straightforward and black has to put in some effort to win this.

# Answer
> 2 votes
**Short answer** : passed pawn. (If white dares then his pawn might fall or black might get protected passed pawn)

Black has active position as much as white. But 1. d4 makes white passive also black has a weird knight on a5. It has no job for now, but it can be so active just after a move.

```

[FEN "2rr2k1/1q2bppp/p3pn2/np1p4/4PQ2/P1N2P1P/BP1R2P1/2R1B1K1 b - - 1 21"]

1... d4 2. Ne2 Rxc1 3. Nxc1 {The knight on c1 is passive now. He has to struggle to become active.} Nc4 {The "weird" knight on h5 is so so good now. White can't remove the knight, just by pushing pawn. Cause the rook is under attack. So it's good to trade the bishop for the knight.} 4. Bxc4 bxc4 {White has protected passed pawn now. But b pawn is disturbing a bit. But there's no way it can help to break black's structure apart immediately.}

```

**Another short answer as summary** : The advantage is for passive pieces vs active pieces. The advantage is for a pawn advantage. The advantage is for advanced pawn. The advantage is for protected passed pawn.

After Nc4 White can just place the rook to another square, but that will make the rook passive or white can win another pawn on b2. The engine saw a way to make white passive that's why the advantage is so high. Though, according to Stockfish at 39 depth the advantage is 5.78 (something around there), it doesn't matter.

# Answer
> 2 votes
First black brings his pawn to d3.

Then he plays Nc4, attacking Rd2 and b2, so Bxc4 bxc4 is forced.

```
[Title "Analysis"]
[StartFlipped "1"]
[FEN "2rr2k1/1q2bppp/p3pn2/8/2p1PQ2/P1Np1P1P/1P1R2P1/2R1B1K1 w - - 0 25"]

```

Black then is up a pawn, and b2 is backward on a half open file. It will sooner or later fall. For example, after Nd7-c5-b3-d4-c2, (Q somewhere), Rb8-b7, Rdb8.

Stockfish's modern evaluation function (NNUE) is based on AI knowledge. The AI evaluates based on remembered probabilities. This type of position happens in a lot of openings, so the AI had comparable positions on board in a lot of training games and learned over time that the probability that black wins is very high, which results in the high evaluation. BTW, Leela sometimes gives an even bigger advantage for black than Stockfish.

# Answer
> 2 votes
Without doing actual tactical reading, I see:

* White's light-square bishop is hemmed in and inactive; of 13 pawns on the board, 10 are on the same colour as that bishop, while Black's remaining bishop is on the opposite colour.
* There is an open diagonal to threaten White's king, which Black's bishop and queen can move to directly. Of course this does not accomplish anything right now, but it points to White's king being generally less safe than Black's.
* While being free to move, White's dark-square bishop can't do very much. It can form a battery with the queen, but that isn't targeting anything; it can defend the open diagonal, but being proactive is better than being reactive.
* White's knight is corralled (it can only move backwards without being taken) and also pinned. (This is where the tactical analysis with d4 starts, since the natural way to exploit a minor piece pin is by threatening with a pawn.)
* Black's knights don't look great either; but one of them can attack the queen directly (which can also be harassed with Bd6), while the other can easily maneuver back to the center (Na5-\>c6-\>e5; it's not a big issue to break the pin momentarily since the knight is still corralled and Black's rooks are connected).
* Black probably has an easier time setting up on the c file, because of the queen positioning.
* While Black's rooks are connected, White's are lined up on a diagonal (with the queen as well). This offers Black the plan of h6 - Nh7 - Bg5.

It's not hard to imagine multiple advantages like this adding up to 6 points.

---
Tags: analysis
---


# Question
Title: How many moves does it take a knight to move 1 square forward?
How many moves does it take a knight to move 1 square forward?

For example, if I wanted to move a knight from e5 to e4 what is the minimum number of moves it would take?

# Answer
Depends on whether the square is diagonal (2 moves) or not (3) as shown in the diagram below:
> 31 votes

# Answer
Not to detract from db\_max's answer with its marvellous picture, but here's another way to arrive at the answer.

When a knight moves, it moves from a white square to a black square or vice versa. You ask about how many moves it takes to move from e5 to e4. e5 is black and e4 is white, so the answer is an odd number. The squares are not a knight's-move apart, so the answer is not 1. As db\_max's picture shows, the knight can move there in 3 moves. So the answer is 3.
> 17 votes

# Answer
Assuming an unobstructed chessboard, it takes three moves to move one square horizontally or vertically and normally takes two to move one square diagonally. However moving from a corner square to the diagonally adjacent square or vice-versa requires four moves.

A knight has eight possible moves, they can be expressed in vector form as (+1,+2), (+2,+1), (-1,+2), (-2,+1), (+1,-2), (+2,-1), (-1,-2), (-2,-1). We observe that the sum of the horizontal and vertical components is always odd, or to put it in chess terms the square a knight lands on will always be a different colour from the one they started on.

This means that moving to a square of the same color will always take an even number of moves, while moving to a square of a different color will always take an odd number. This implies that a one square diagonal move will always take at least two moves, and a one square straight move at least three.

On an infinite chess board, we can build one square diagonal moves by combining two regular knight moves.

```
(+1,+1) = (+2,-1) + (-1,+2)
(-1,+1) = (-2,-1) + (+1,+2)
(+1,-1) = (+2,+1) + (-1,-2)
(-1,-1) = (-2,+1) + (+1,-2)

```

To build a straight move we can combine one of our diagonal moves with a regular knight move.

```
(+1,0) = (+2,-1) + (-1,+1) = (+2,+1) + (-1,-1)
(0,+1) = (-1,+2) + (+1,-1) = (+1,+2) + (-1,-1)
(-1,0) = (-2,+1) + (+1,-1) = (-2,-1) + (+1,+1)
(0,-1) = (+1,-2) + (-1,+1) = (-1,-2) + (+1,+1)

```

On a real chessboard not all moves are always possible. For straight moves, and most diagonal moves we can work around this by re-ordering the moves, starting with a move that moves away from the edge/corner and ending with a move that moves back towards the edge/corner.

However if we are trying to move diagonally from or to a corner, re-ordering does not help us. Whichever order we perform the two move sequence in, it will take us outside the board. Thus to move from a corner to the diagonally requires first moving to a square adjacent to our destination (since these are the only possible moves from a corner). Then using three further moves to actually reach our destination.
> 5 votes

---
Tags: knights, mathematics
---


title: How to arrange engine games?

text:
# Question
Title: How to arrange engine games?
I have heard in various places that we can make engines play against each other from a certain given position. I want to know how exactly to do that. Is there a website where I can put a position and make Leela and Stockfish (14 or 15 preferably) play a position that I want them to play, or is it something only a few people have the advantage of doing?

Please let me know whether there are ways for me to arrange for such games.

# Answer
Try:

You will see a sample usage where two engines are paired togerther:

> cutechess-cli -engine cmd=sloppy -engine cmd=sloppy -each proto=xboard tc=40/60 -rounds 10
> 3 votes

# Answer
Arena seems to be a good fit for what you want to do. You can install any engines you want, set up any position and make them play against each other using the Game-\>Demo command.
> 2 votes

---
Tags: engines, stockfish, leela
---


title: 7. ... e6 in Classical Caro-Kann

text:
# Question
Title: 7. ... e6 in Classical Caro-Kann
Where can I find information on the 7. ... e6 variation of classical Caro-Kann, preferrably a book? It was played in the Anand-Carlsen world championship match 2013.

```
[FEN ""]
1. e4 c6 2. d4 d5 3. Nc3 dxe4 4. Nxe4 Bf5 5. Ng3 Bg6 6. h4 h6 7. Nf3 e6

```

The following books do not cover the classical variation (4. ..Bf5) with 7. ..e6:

* Rambaldi's The Caro-Kann Revisited
* Schandorff's GM Repertoire
* Schandorff's Playing the Caro-Kann
* Gallagher's Starting Out
* Lifetime Repertoires: Caro-Kann by GM Erwin L'Ami
* Opening Repertoire - The Caro-Kann (Houska Jovanka, Everyman 2015)
* The Caro-Kann move by move (by Cyrus Lakdawala)
* The Modernized Caro-Kann (Daniel Fernandez)

(some of these cover the classical variation, but with 7. ..Ne7 instead)

# Answer
> 1 votes
Vidit Gujrathi - Fashionable Caro-Kann. Check his video at Bilibili. You can download the Bilibili app. It's a solid 'secretive' line (7...e6) for Caro players. I made a pgn file and will use the variation as the main line.

# Answer
> 3 votes
The move 7...e6 is mentioned briefly by Andy Soltis on p. 105 of the *Caro-Kann Defense* book in the Understanding Chess series from R.H.M. Press. He doesn't recommend it:

> But at this moment accuracy is essential. After 7...e6 White gains too much time by forcing Black's Bishop on g6 to move again; e.g., 8. Ne5 Bh7 9.Bd3 and if 9...Qxd4? 10. Nxf7! (for if 10...Kxf7 11. Bg6+! wins the Queen), or if 9...Bxd3 10. Qxd3 Nf6 11. Bd2 Nbd7 12. Ng6! (for if 12...fxg6 13. Qxg6+ Ke7 14. Bb4+ wins. Black can defend better in these lines (for example, 10...Nd7 instead of 10...Nf6), but basically he has lost a move (8...Bh7).

This is from 1980, and Soltis's 12. Ng6 may not stand up to engine analysis.

# Answer
> 2 votes
Chapter 1 of "*...c6 Playing the Caro-Kann and Slav as Black*" by Cyrus Lakdawala and Keaton Kiewra is 70 pages long and covers the Classical Variation in great detail. This is a good book which explores the ideas behind the moves as well just giving analysis. 10 games are analyzed in the chapter, 2 of which feature the black move 'e6' although on move 6 rather than move 7.

It's bizarre. As you say almost none of the books claiming to cover the Caro-Kann even mention the Classical Variation. I just checked in Volume 1 of the normally excellent John Watson's "*Mastering the Chess Openings*" to see what he covers for the Caro-Kann. Obscure (to me) lines like the "Short Variation" and "Zviagintsev Variation" get a mention but no Classical!

---
Tags: opening, books, caro-kann
---


# Question
Title: What to trade when there's one superior/inferior minor piece in the position?
Consider this position:

```
[FEN ""]
1. d4 Nf6 2. c4 c5 3. d5 e6 4.Nc3 exd5 5.cxd5 d6 6.e4 Nbd7 7.Nf3 Ne5 8.Nxe5 dxe5 9. Bb5+ Bd7 10. Bxd7+ Qxd7 11. O-O c4 12. Bg5 Be7 13. Qe2 b5 14. Rfd1 O-O 15. d6 Bd8 16. Bxf6 Bxf6 17. a4 b4 18. Nd5 Qxd6 19. Qxc4

```

This is a position where White has the superior minor piece (the knight). In such kind of positions where there is one minor piece for each player left on the board, and all the heavy pieces are there (rooks and queens) too. What trades should the player with the superior and inferior minor piece do or avoid? Or there's no such heuristic or rule of thumb here?

# Answer
In most cases, Knights are happy when the position is closed and bishops are happy when it's an open position. By *closed*, I mean pieces are not easy to move, and in *open*, pieces are free to move. In these cases, one should try to keep the piece that suits the type of position.

In the position given above, the white knight is controlling many crucial squares in black's territory. Black has a bishop blocked by its own pawn and there's really nothing that black can do to kick the knight from the d5 square. If you are black and you ever get a chance to trade then go for it. White should prevent any trades in this position or else they'll lose all their advantage.

If the major pieces are still on the board then we should try not to exchange pieces unless there's a good advantage for us. Before exchanging anything just try to think will this position be good for me in the upcoming 5-10 moves. If yes, then go for it. :)
> 3 votes

# Answer
This is an interesting position. White has a bit of an advantage, and a strong player would certainly not agree to a draw, but I don't think that the advantage is anywhere close to winning yet. White would need to force a "second weakness" and to do that they probably want to keep as much on the board as they can.

One thing that I feel fairly sure of. Black has the move and must play ..a5. Otherwise White will play a5 and artificially isolate the pb4. Maybe that it still not winning but it will give White a little more to work with. The inferiority of the Black Bishop is that it is hard to see any creative way to employ it, whereas Whites Knight should not just sit smugly on d5 and not try to do anything more, but can and must seek creative activity.

For example, it can transfer to f5, the K-side Pawns can advance, and the Rooks can shift to that side of the board. There might not be a mating attack, but there could be the possibility of that second weakness.

Another possibility, which I think may be preferable, is to put the Knight on c4 and support it with b3. Place the major pieces actively but dont exchange them yet and start moving the King into the center. Piece activity allows you to do this without Black following suit. Then you swap off the majors and you have a won endgame because of better King placement.

A grandmaster might be able to foresee an entire process, but I am not a grandmaster. I would try to keep doing good things and hope for increasing clarity. The crucial thing is that **having better pieces enables you to be more creative.** I think that this is better advice that trying to present you with a formula.
> 1 votes

---
Tags: strategy, minor-pieces
---


title: Why is Qf3 losing in this position?

text:
# Question
Title: Why is Qf3 losing in this position?
```
[FEN ""]
[startply "16"]
[StartFlipped "1"]

1. e4 d6 2. Bc4 Nf6 3. Nc3 g6 4. d3 Bg7 5. Nf3 Nc6 6. O-O e5 7. Ng5 O-O 8. Bxf7+ Rxf7 9. Qf3

```

Why does the engine go from -1.5 to -8.5 after the queen move? There isn't an opportunity to trap the queen yet and the black is only two points ahead in material. My guess is that the queen walks into a discovered attack by the rook and the queen can be immediately attacked with Nd4. I played Rf8 afterwards to keep my rook on the f file. The top engine line is just to move the queen back to where it came from and then the knight is kicked out too.

# Answer
White is a piece down for just a pawn in this position. Taking the rook would give them a reasonably balanced position, but by refusing to take they get a totally lost one.

There are also some ideas with Bg4 and Nd4 that speculate with trapping the queen or taking on c2 (potentially forking the rook and queen if she moves to the wrong square).

I wouldn't pay too much attention to the specific number. Whether it's -3 or -7 it doesn't matter much. The fact is that White should have taken the rook and any other move is a blunder.
> 9 votes

# Answer
It seems like white played Bxf7, and after Rxf7, instead of taking the rook with Nxf7, white played Qf3. Now black -among others- can play the simple Rf8 and are a piece up for a pawn.

The fact that the advantage is so large just depends on the engine and its version. For example, from Stockfish 15.1 evaluations are not that extreme (in my laptop it's "only" -5).

In any case, white position goes from -1 to completely lost not because Qf3 puts the queen in danger or anything like that, but just because they didn't play Nxf7 (winning a rook for a knight), sort of balancing the material on the board.
> 5 votes

---
Tags: engines, analysis
---


# Question
Title: Moving a piece to a square protected by 5 opponent's pieces
At the 5th round of the 2022 FIDE World Team Championship, in the game between Ivanchuk and Van Foreest, White played the following winning move:

```
[FEN "1n1q2k1/2r1rp1p/pp1b1np1/3pN3/3P4/BP4PB/P1R2P1P/2R2QK1 w - - 10 26"]
[White "Ivanchuk"]
[Black "Van Foreest"]

1. Nd7!

```

placing his knight to a square that is protected by 5 black pieces (the two rooks and knights and the queen).

Has this (perhaps with more attacking pieces) ever occurred again in a FIDE-rated game between two GMs?

# Answer
> 7 votes
Thanks to this CQL query:

```
cql(input Mega_Database_2022.pgn)

flipcolor {
    square x in [KNBRQ] attackedby a {
        move previous to x from [KNBRQ]
        not move previous capture a

        not check
        sort a attacks x >= 5
    }
}

```

I found some quite interesting examples:

7 attackers:

```
[Event "Moscow-ch 65th"]
[White "Naumkin, Igor"]
[Black "Smagin, Sergey"]
[Site "Moscow"]
[Result "1-0"]
[WhiteElo "2445"]
[BlackElo "2505"]
[FEN ""]
[StartPly "49"]

1. d4 d5 2. c4 c6 3. Nc3 Nf6 4. Nf3 dxc4 5. a4 Bf5 6. e3 e6 7. Bxc4 Bb4 8. O-O Nbd7 9. Nh4 Bg4 10. f3 Bh5 11. g4 Nd5 12. Ng2 Bg6 13. Na2 Bd6 14. e4 Ne7 15. Nc3 h5 16. g5 h4 17. f4 Qa5 18. Ne3 O-O-O 19. Be2 Nb6 20. Bd2 Bxf4 21. Rxf4 Rxd4 22. Qc1 Rhd8 23. Be1 Qxg5+ 24. Rg4 Qc5 25. Ncd5 Qxc1 26. Nxe7+ Kd7 27. Rxc1 Bh5 28. Rxg7 Bxe2 29. Ng8 Kc8 30. Bxh4 Rf8 31. a5 Nd7 32. Rc2 Bb5 33. Nf6 Nxf6 34. Bxf6 Rxe4 35. Rg3 Ra4 36. h4 Rxa5 37. h5 Ra1+ 38. Kh2 Bd3 39. Rcg2 Ra4 40. Rg4 Ra5 41. Rh4 Rb5 42. h6 Rb3 43. Nc4 Bh7 44. Rg7 Bg6 45. Rxg6 fxg6 46. h7 b5 47. h8=Q Rxh8 48. Rxh8+ Kc7 49. Be5+ Kd7 50. Rh7+ Ke8 51. Nd6+ 1-0

```

---

```
[FEN ""]
[Event "Nikaia op 19th"]
[White "Anastasopoulos, Spyros"]
[Black "Kotrotsos, Vasilios"]
[Site "Nikaia"]
[Round "3"]
[Annotator ""]
[Result "0-1"]
[Date "2011.08.27"]
[WhiteElo "2177"]
[BlackElo "2332"]
[StartPly "42"]

1. d4 g6 2. e4 Bg7 3. Nf3 d6 4. Bc4 Nf6 5. Qe2 O-O 6. h3 Nc6 7. O-O Nd7 8. c3 e5 9. Bg5 Qe8 10. Na3 a6 11. Nc2 Nb6 12. Bb3 Na5 13. dxe5 Nxb3 14. axb3 dxe5 15. Be3 Nd7 16. Qc4 c6 17. Rad1 Qe7 18. Rd2 Re8 19. Rfd1 Nf8 20. Rd6 Ne6 21. Bb6 Nd4 22. cxd4 Qxd6 23. Ne3 Be6 24. Qa4 exd4 25. e5 Qe7 26. Qxd4 Bxb3 27. Rd3 Bd5 28. Nxd5 cxd5 29. Qxd5 Qe6 30. Qa5 Rac8 31. Re3 Rc1+ 32. Kh2 Rd1 33. Qa4 Qd7 34. Qh4 h6 35. Bd4 Qd5 36. Bc3 b5 37. Qf4 Rd3 38. Re1 Re6 39. h4 Rd1 40. Re3 Qc4 41. Re4 Qd5 42. Re3 Re8 43. h5 g5 44. Nxg5 hxg5 45. Qxg5 Qd8 46. Qg4 Kh7 47. h6 Bxh6 48. Qf5+ Kg8 49. Rg3+ Kh8 50. Qh5 Re6 51. Qxf7 Qe8 52. Qf5 Rd7 53. Rh3 Rh7 54. f4 Qf7 55. Qxf7 Rxf7 56. g3 Kg7 57. Kg2 Kg6 58. Kf3 b4 59. Bxb4 Rxe5 60. Bc3 Rb5 0-1

```

---

6 attackers:

```
[Event "Odorheiu Secuiesc zt"]
[White "Dumitrache, Dragos Nicolae"]
[Black "Mrva, Martin"]
[Site "Odorheiu Secuiesc"]
[Round "8"]
[Result "0-1"]
[WhiteElo "2530"]
[BlackElo "2400"]
[FEN ""]
[StartPly "42"]

1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. Bd3 O-O 6. Nge2 e5 7. d5 a5 8. a3 Nbd7 9. O-O c6 10. b3 Nc5 11. Bc2 b5 12. cxb5 cxd5 13. exd5 Bb7 14. Rb1 Rc8 15. b4 axb4 16. Rxb4 Qa5 17. Bb2 Qa8 18. f3 Bxd5 19. Ng3 Bb7 20. Qxd6 Rfd8 21. Qxe5 Nfe4 22. Qxg7+ Kxg7 23. Ncxe4+ Kf8 24. Nf6 Rd6 25. Re1 Re6 26. Rxe6 Nxe6 27. Ra4 Rxc2 28. Rxa8+ Bxa8 29. Nxh7+ Ke7 30. Bf6+ Kd7 31. Nf1 Re2 32. Ng3 Ra2 33. Be5 Nc5 34. h4 Nd3 35. Bd4 Nf4 36. Bf2 Rxa3 37. Ne4 Ra1+ 38. Kh2 Ra2 39. Kg3 Nh5+ 40. Kh2 Bxe4 0-1

```

---

5 attackers:

```
[Event "Groningen op"]
[White "Zak, Uriel"]
[Black "Schmittdiel, Eckhard"]
[Site "Groningen"]
[Round "4"]
[Result "0-1"]
[WhiteElo "2370"]
[BlackElo "2495"]
[StartPly "34"]
[FEN ""]

1. e4 c5 2. Nf3 Nc6 3. c3 d5 4. exd5 Qxd5 5. d4 Nf6 6. Be2 e6 7. O-O Be7 8. Na3 O-O 9. Nc2 a6 10. Be3 Ng4 11. Bf4 b5 12. dxc5 Qxc5 13. Nfd4 Nge5 14. Be3 Rd8 15. Qc1 Qd5 16. Rd1 Bb7 17. Nxb5 Nd4! 0-1

```

---

```
[Event "UKR-ch sf op"]
[White "Kobylkin, Evgeni"]
[Black "Kislinsky, Alexey"]
[Site "Alushta"]
[Result "1-0"]
[WhiteElo "2315"]
[BlackElo "2412"]
[StartPly "49"]
[FEN ""]

1. d4 d5 2. c4 e5 3. dxe5 d4 4. Nf3 Nc6 5. g3 Be6 6. Nbd2 Qd7 7. Bg2 O-O-O 8. O-O Bh3 9. Bxh3 Qxh3 10. Ne4 f6 11. exf6 gxf6 12. Bf4 h5 13. Nh4 Bh6 14. Ng6 Rh7 15. Qd3 Rg7 16. Bxh6 Nxh6 17. Nf4 Qf5 18. Nd5 Ne5 19. Qxd4 c6 20. Qxa7 cxd5 21. Nc5 Nc6 22. Qa8+ Nb8 23. cxd5 Qxd5 24. e4 Qc6 25. Nd7 Rgxd7 26. Rac1 Ng4 27. Rxc6+ bxc6 28. a4 Ne5 29. b4 Rg7 30. b5 h4 31. b6 h3 32. f4 Nc4 33. Rc1 Rd4 34. a5 Rgd7 35. a6 Rd1+ 36. Rxd1 Rxd1+ 37. Kf2 Rd2+ 38. Kf3 Rd3+ 39. Kg4 Rd7 40. a7 Rg7+ 41. Kh5 1-0

```

---

Short explanation of the query:

* Find positions where *at least* one square occupied by a white piece (not a pawn) is attacked by Black and:
    + that white piece recently occupied the square,
    + without capturing a black piece,
    + without checking the black king.
    + where at least 5 black pieces attack that square. Sort by the amount of the attackers.

`flipcolor` repeats the search with colors interchanged.

---
Tags: history, records, grandmaster, master-games, patterns
---


# Question
Title: Panov-Botvinnik Attack: position analysis
I am a beginner in chess (1313 lichess, 1177 chess.com rapid) and am in the process of learning the basics of the Panov attack from the Hanging Pawns Youtube channel. In this video, at 15:00,

```
[FEN ""]
[Startply "19"]

1. e4 c6 2. d4 d5 3. exd5 cxd5 4. c4 Nf6 5. Nc3 Nc6 6. Bg5 Bf5 7. Bxf6 exf6 8. cxd5 Nb4 9. Bb5+ Bd7 10. Qe2+ Qe7 11. Bxd7+ Kxd7 12. Kd2 Qxe2+ 13. Ngxe2

```

the presenter, in trying to prove that e6 is the correct move for Black on move 6, states that the black king is "naked, unsafe and completely lost" on move 10 if Black plays a normal move such as Bf5. I did not understand why, as the queen could easily block the check, so I ran the line through the lichess engine which gave me the above continuation.

I understood:

1. Why we can't block with the bishop: d6 wins the bishop.
2. Why Kd2 was played: to prevent Nc2.

I still do not understand why the position literally went from +0.1 to +1.8 so suddenly. Black is not even that far behind in development. What does White have in this position?

# Answer
> What does White have in this position?

A number of things:

1. White has an extra passed pawn in the center plus better pieces.
2. The doubled passed pawns are quite difficult to attack and control a lot of squares.
3. White's next move is likely to be a3 forcing the black knight back to a bad square on a6.
4. Black's kingside pawn majority (4 vs 3) is crippled and, with best play from white, is not going to create a passed pawn.

Black has nothing in return.
> 6 votes

---
Tags: analysis, beginner, caro-kann
---


# Question
Title: Has O-O ever been played without moving the e or g pawns?
Normally the e or g pawn must be moved (to release the bishop) before castling kingside is possible. However, it’s theoretically possible for a knight to have taken the bishop without these pawns ever moving, and thus for short castles to be played with the pawns remaining in place.

Silly example:

```
[FEN ""]

1. Nf3 Nf6 2. Ng5 a6 3. Ne6 a5 4. Nxf8 a4 5. Ne6 a3 6. Ng5 O-O

```

Is this known to have ever happened in a real game?

# Answer
> 42 votes
This CQL query:

```
cql(input Mega_Database_2022.pgn)

flipcolor {
    {
        move from K o-o
        Pg2 Pe2
    } or {
        move from K o-o-o
        Pb2 Pd2
    }
}

```

returns 224 (!) games when run against Mega Database 2022. There are no games where O-O-O occurred with the pawns in b, d files unmoved.

Only in two of these 224 games it was White who castled with pawns on g2, e2:

```
[Event "Montigny le Bretonneux op"]
[Site "Montigny le Bretonneux"]
[Date "1999.??.??"]
[Round "4"]
[White "Trifigny, Yves"]
[Black "Edery, Laurent"]
[Result "0-1"]
[ECO "A80"]
[EventDate "1999.11.??"]
[FEN ""]
[StartPly "28"]

1.d4 f5 2.c3 b6 3.Bg5 h6 4.Bf4 Nf6 5.Nd2 Bb7 6.f3 e6 7.Qc2 Nd5 8.Nh3 g5 9.Be5
Rg8 10.Bg3 Ne3 11.Qd3 Nxf1 12.Nxf1 d5 13.Nd2 Bd6 14.Be5 Qe7 15.O-O
Nd7 16.Bxd6 Qxd6 17.c4 g4 18.fxg4 dxc4 19.Nxc4 Qc6 20.Rf2 Rxg4 21.Rf3 O-O-O 22.
Nf4 Rxf4 23.Raf1 Rxf3 24.exf3 Qd5 25.b4 Ne5 26.Nxe5 Qxe5 27.Rd1 Qd5 28.Rd2 b5
29.a3 Rg8 30.Rf2 h5 31.h4 Qc4 32.Qe3 Bd5 33.Kh2 Rg6 34.g3 Bb7 35.Rd2 Qc6 36.Rd3
Qxf3 37.Rc3 Qd5 38.Rc5 Qa2+ 0-1

```

---

```
[Event "Izmir op 12th"]
[Site "Izmir"]
[Date "2013.09.06"]
[Round "7"]
[White "Lorparizangeneh, Shahin"]
[Black "Canbulan, Arda"]
[Result "1-0"]
[WhiteElo "2234"]
[BlackElo "1868"]
[ECO "A52"]
[EventDate "2013.09.01"]
[FEN ""]
[StartPly "36"]

1.d4 Nf6 2.c4 e5 3.dxe5 Ng4 4.Bf4 Bb4+ 5.Nd2 d6 6.Nf3 dxe5 7.Bg3 e4 8.a3 Bxd2+
9.Nxd2 e3 10.fxe3 Nxe3 11.Qb3 Qe7 12.Bf4 Nxf1 13.Nxf1 Nc6 14.Ne3 O-O 15.Nd5 Qe4
16.Qd3 Bf5 17.Qxe4 Bxe4 18.Nxc7 Rad8 19.O-O Nd4 20.Rf2 Ne6 21.Nxe6
1-0

```

In the rest, Black was castling. Most of them were ECOs B17:

```
[FEN ""]

1.e4 c6 2.d4 d5 3.Nc3 dxe4 4.Nxe4 Nd7 5.Ng5 h6 6.Ne6 Qb6 7.Nxf8

```

I had to filter these out with `not eco "B17"`. Here are some unique examples:

```
[Event "YUG-ch (Women)"]
[Site "Budva"]
[Date "2002.??.??"]
[Round "?"]
[White "Grujic, Danijela"]
[Black "Laketic, Milica"]
[Result "0-1"]
[WhiteElo "2180"]
[BlackElo "2130"]
[ECO "B02"]
[EventDate "2002.08.??"]
[StartPly "35"]
[FEN ""]

1.e4 Nf6 2.Nc3 d5 3.e5 Nfd7 4.e6 fxe6 5.d4 c5 6.Nf3 Nc6 7.Bb5 a6 8.Bxc6 bxc6 9.
g4 Qc7 10.Qe2 cxd4 11.Nxd4 e5 12.Ne6 Qd6 13.Nxf8 Nxf8 14.Bd2 Ne6 15.O-O-O Nd4
16.Qe3 Bxg4 17.Rde1 Nf3 18.Nd1 18...O-O 19.Ref1 d4 20.Qb3+ Be6 21.Qa4
Bd5 22.Ba5 c5 23.h3 Rab8 24.b3 c4 25.Nb2 c3 26.Nc4 Qh6+ 27.Kb1 Rfc8 28.Ka1 Bxc4
29.bxc4 Nd2 30.Re1 Qc6 31.c5 Qxc5 32.a3 Qb5 33.Qxb5 Rxb5 34.Bb4 Kf7 35.f4 e4
36.Rh2 d3 37.Rg2 a5 38.Bxe7 Kxe7 39.Rxg7+ Kf6 40.Rxh7 Rcb8 41.Rh6+ Kg7 42.Re6
Rb1+ 43.Rxb1 Rxb1+ 44.Ka2 Rb2+ 45.Ka1 Rxc2 46.f5 Nb3+ 47.Kb1 Rb2# 0-1

```

---

```
[Event "Wch Seniors 19th"]
[Site "Condino"]
[Date "2009.10.29"]
[Round "3"]
[White "Arkhangelsky, Boris Nikolaevich"]
[Black "Danner, Georg"]
[Result "1/2-1/2"]
[WhiteElo "2292"]
[BlackElo "2440"]
[ECO "B57"]
[EventDate "2009.10.27"]
[FEN ""]
[StartPly "35"]

1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 d6 6.Bc4 Na5 7.Bb5+ Bd7 8.Qe2 Rc8
9.Bg5 Bxb5 10.Qxb5+ Nd7 11.Qe2 Nc4 12.O-O h6 13.Ne6 Qa5 14.Nxf8 Nxf8 15.Bc1 Ne6
16.Nd5 Qd8 17.b3 Ne5 18.Bb2 O-O 19.Rad1 f6 20.c4 b6 21.f4 Nd7
22.e5 fxe5 23.fxe5 Rxf1+ 24.Qxf1 dxe5 25.Qe2 Nc7 26.Qg4 h5 27.Qh3 Qe8 28.Nb4
Nf6 29.Bxe5 Ng4 30.Qg3 Rd8 31.Re1 Nxe5 32.Qxe5 Rd7 33.h3 Qg6 34.Nd5 Nxd5 35.
cxd5 Kh7 36.Re3 Qf7 1/2-1/2

```

---

```
[Event "Agosto de Victorias op"]
[Site "Mayabeque"]
[Date "2018.08.07"]
[Round "8"]
[White "Hernandez Sosa, Oscar Luis"]
[Black "Gutierrez Espinosa, Karen"]
[Result "1-0"]
[WhiteElo "2055"]
[BlackElo "2061"]
[ECO "A31"]
[EventDate "2018.08.04"]
[FEN ""]
[StartPly "25"]

1.c4 Nf6 2.Nc3 c5 3.Nf3 b6 4.d4 cxd4 5.Nxd4 Bb7 6.Bg5 Nc6 7.e4 d6 8.Be2 Nd7 9.
O-O h6 10.Ne6 Qc8 11.Nxf8 Nxf8 12.Be3 Ng6 13.f4 O-O 14.Bg4 Qd8
15.Rf3 e6 16.Rg3 Nge7 17.Bh3 f5 18.Qh5 Kh8 19.Rd1 a6 20.e5 d5 21.cxd5 exd5 22.
Nxd5 Nxd5 23.Qg6 Qe7 24.Rxd5 Rac8 25.Bxf5 Rxf5 26.Qxf5 Qb4 27.Rd1 Qc4 28.Qd7
Rg8 29.Qxb7 Qe2 30.Rf1 1-0

```

---
Tags: history, castling, famous-games, patterns
---