title: Tournaments for adults only?

text:
# Question
Title: Tournaments for adults only?
Are there any over-the-board tournaments open only to persons over 18?

Everywhere I go it's like a school field trip, more than half the players are from some elementary or middle school, all parents in tow. And as I am in the ~1600 rating range myself, I end up playing nothing but kids and I find it unpleasant.

First of all, it's a no-win situation. If you beat them, you feel like a bully taking candy from a baby.

Most of the time it's fine, but I've had a few very negative experiences, especially:

* A kid about 9 years: he played a fantastic opening against me, he was up a pawn and had a crushing position. He proceeds to go get all his friends to look at the board, all snickering. Then, I fight back and when he realizes I'm about to win his rook and take the initiative he breaks out into tears, like inconsolable. It was horrible. The TD awarded me the game as forfeit.
* A kid about 14 years old: He plays really fast, and I go up a knight and have a good attack going. It's a complex position but I'm easily going to be able to finish it. He proceeds to get up, walk around for 20 minutes (game 60 time control), comes back, makes a move, then gets up again, another 10 minutes, and on and on until he had a few mins left and then he played to the end (I won easily.) It was ridiculous. I complained to the TD but he said there's nothing he could do.

So I can't play tournaments anymore, it's unpleasant. Are there any tournaments that are open to only adults?

# Answer
> 23 votes
There are definitely some, but they are, clearly, not the norm as most organizers want to get the most players they can, and thus, make the most money they can.

Here are a few links of places that have regular adult tournaments. Some of these tournaments have gone by, but if they did them before, they probably would do them again. There are surely more, but I am not going to try to track down every one of them.

Of course, and I am one now, there are also senior events for those over 50; so you have something to look forward to.

Starting a local club that does one game per week, and excluding kids, might also work for you.

I do feel your pain. I got whacked by the number one 8-year-old in the country a week ago. His behavior was totally fine, but kids are always so underrated.

Berkeley, California

Austin, Texas

New Jersey

Tucker, Georgia

# Answer
> 27 votes
There are tournaments for 50+ years old. This is great as you can avoid immature 30 year olds.

# Answer
> 16 votes
There aren't many, but there are some. Sometimes, oddly enough, it can help to find a largish *scholastic* event and see if there's a corresponding adult event at the same time. For example, Wisconsin holds the Wisconsin Junior Open every year. And, at the same time and location (but on a different floor), they also hold the Veteran's Tournament, which is only open to adults.

# Answer
> 10 votes
If you find yourself in the UK, the Central London Chess Congress at Imperial College has an over-18's policy due to licensing restrictions on the venue. It is, not just for this reason, one of my favourite events on the chess calendar.

# Answer
> 5 votes
Yes, playing kids *can* be quite annoying, and I've suffered through some such games. Fortunately, I can say it isn't always that way, as some younger players know courteous tournament behavior.

OTOH, playing adults can be unpleasant also. I once played a guy who was at least in his thirties and seemed intent on doing everything he could to be distracting: clock smashing (for the whole game, not just in time trouble), heavy sighs when I was thinking, muttering obscenities after realizing he made bad moves, making "A-ha!" types of exclamations when he found good moves, frequent requests to check my scoresheet, etc.

To address the actual question (and why I'm answering this 3 years after it was asked): The Charlotte Chess Center is now hosting "At least twenty-one" (ALTO) tournaments, where - as you likely expect - the participants must be at least 21 years of age.

https://www.charlottechesscenter.org/alto

(Checking on this, I see that the link now takes you to the CCC's events page and I'm not seeing another ALTO tournament on there soon. Hopefully that changes.)

I've not been to one myself, but they seem to be fairly popular. As such, I expect other venues may start offering such tourneys themselves.

Another possibility is to see if there are parents sections in local scholastic tournaments. Prior to the SARS-COV-2 outbreak, our state association frequently had such a section at their scholastics. When I asked about it, the TD said that the point of the section was to offer chess playing parents and team coaches a chance to play while the kids they were supervising were playing their games. However, he said he'd allow any adult who wanted to play to do so.

---
Tags: tournament
---


# Question
Title: What positions are there where the final actual outcome in real games contradict engine evalulation?
This question triggered by a position reached today round 9 in WCC 2023. According to lichess Masters DB that position was reached 17 times in which black won 3 times and the rest are drawn which is interesting since this position is +0.3 according to the Engine. Understabley this is too small a sample of 17 games of which many draws; But I have to wonder, are there position that were reached 20+ time or so and DB results contradict the engine evaluation?

```
rnb2rk1/1pp1qppp/5n2/pBb1p3/P3P3/2P2N2/1PQN1PPP/R1B2RK1 w - - 3 11

```

# Answer
Sure, here are some examples where the game ends drawn with the engine evaluation at MX (i.e., mate in X moves). As given by Wiki, Robert Kempinski (2498) – Vladimir Epishin (2567) \[E60\] Bundesliga 0001 Germany (5.3), 07.01.2001

```
[FEN "8/8/8/8/4K3/2kn4/5b2/8 w - - 0 1"]

```
> -2 votes

---
Tags: database
---


title: Book series to improve

text:
# Question
Title: Book series to improve
I have an Elo score of about 800 and I am looking for book series to improve (projecting even up to very high scores). Do you have any recommendations? Possibly even more than one series, so as to cover more score ranges. For example:

One series to go from 800 to 1300

One series to go from 1300 to 1700

Obviously I have taken example scores.

Preferably series that cover the 3 main macro-areas quite completely: opening, middlegame and endgame.

I already know some book series, a couple of them: Seirawan's series and the Yusupov series, but I suppose there are many others. The problem is that I don't know what their level (in terms of Elo score) is in order to read them. So I would need some kind of plan based on the score. Example: from 800 to 1300 use Seirawan's series, etc..

# Answer
You appear to be asking for a concrete plan. It is almost like a factory. But learning chess isn't a factory and what you learn when at what rating is different for everyone. As such, I will give not give book specifically for (x-y) rating, but I will categorize them by whether they are meant for beginners, intermediates, masters, etc. You will notice some categorized as both, because not every book fits nicely into a box.

> Beginners

1. "Winning Chess" series by Yasser Seirawan (really aimed for both beginners and intermediates)
2. "Chess for Kids" series by Michael Basman
3. "Chess Tactics for Kids" by Murray Chandler
4. "Starting Out" by Everyman Chess
5. "Chess Openings for White Explained" by Roman Dzindzichashvili
6. "Modern Chess Openings" by Nick de Firmian
7. "Chess Strategy" by Edward Lasker
8. "Winning Chess Endings" by Yasser Seirawan
9. "Chess Tactics" by Martin Weteschnik
10. "Chess Skills" by John Nunn

> Intermediate

1. "The Yusupov Chess" by Artur Yusupov
2. "Silman's Complete Endgame Course" by Jeremy Silman
3. "Winning Chess" series by Yasser Seirawan (really aimed for both beginners and intermediates)
4. "The Chess Structures" by Mauricio Flores Rios
5. "The ChessBase University" by Dorian Rogozenco
6. "The ChessCafe Puzzle" by Karsten Mueller
7. "The Art of Attack in Chess" by Vladimir Vukovic
8. "The Reassess Your Chess" by Jeremy Silman
9. "The Soviet Chess Conveyor" by Mikhail Shereshevsky
10. "Positional Play" by Mark Dvoretsky

I am going not going to add master here, but these should be helpful. I know that I gave you **a lot** of options. And that goes back to what I said earlier. One chess book (series) will not help everyone. Also, even if you read every single book on this list (please don't) then there is no gaurantee that you would improve to 1300 or 1700 ELO.
> 5 votes

---
Tags: learning, books, elo, study
---


title: Changing your good against a bad bishop

text:
# Question
Title: Changing your good against a bad bishop
I'm not *completely* dumb when it comes to positional play but I never understood what I would get in return for, say, Bd3 Bxd3 in the Caro Kann (e.g. Tal Variation). Or Bd6 Bxd6 in the London. (In the latter case, I could say "one less piece about to sacrifice itself somewhere in my castling position", but the former?)

The short answer might be "A statically bad bishop can still be good dynamically", but please, no stock phrases :-) So what is the *exact* reason (in the Caro Kann)?

Related but unrelated (I see no tactical reasons concerning the Caro Kann, at least no immediate)

Related but unrelated (So, *there* they play Be2. Chess is so illogical... :-)

# Answer
> 7 votes
This is perhaps more of a language problem rather than a chess one: we tend to call bishops that have pawns on their same color as "bad" and those who don't as "good". This correlates most of the time with how strong the bishops actually are, but not always

Taking the London example as reference, how "good" would Black's bishop be if it was passively sitting on e7? Note how Black doesn't try to change the bishop if they decide to develop it via g7 instead.

On the other hand, in a line like **1.d4 d5 2.Nf3 Nf6 3.Bf4 e6 4.e3 Bd6**, the bishop trade allows Black to fight for the e5 square. If White takes then the queen goes to d6 already tartetting e5 with an extra piece. If White retreats, then Black wins a tempo it can use to continue with ...c5, ...Qc7 and ...Nd7. Note that if Black is successful in pushing ...e5, suddenly the "bad" bishop on c8 gets a new life.

We could also say that the White bishop on f4 is a strong piece. Even though it "crashes" into its own central pawn chain, it's sitting outside of it, so the only movements it has restricted are Be3, Bd2 and Bc1 (which White would almost never want to do either way). More importantly, it's controlling the e5 square which is critical in all of White's plans.

---
Tags: bad-bishop
---


# Question
Title: What's the rationale behind chess engines conditionally allowing threefold repetitions when assigning a draw score?
When a chess engine sees a position *p* repeated once (i.e. position *p* occurred twice) it immediately assigns the second occurrence of position *p* a draw score. This makes sense because position *p* doesn't need to occur thrice in order for the chess engine to realize that it's not making progress (i.e. a twofold repetition is just as drawn as a threefold repetition).

Many chess engines do just this. They assign a draw score to all twofold repetitions. However, some of the best chess engines such as Stockfish and Ethereal don't assign a draw score to all twofold repetitions. If the first occurrence of position *p* is not strictly after the root node then they don't assign a draw score to the twofold repetition. Instead, the position needs to be repeated twice (i.e. it needs to be a threefold repetition) in order for it to be assigned a draw score.

For example, consider the following `drawnByRepetition` function from the Ethereal source code:

```
int drawnByRepetition(Board *board, int height) {

    int reps = 0;

    // Look through hash histories for our moves
    for (int i = board->numMoves - 2; i >= 0; i -= 2) {

        // No draw can occur before a zeroing move
        if (i < board->numMoves - board->fiftyMoveRule)
            break;

        // Check for matching hash with a two fold after the root,
        // or a three fold which occurs in part before the root move
        if (    board->history[i] == board->hash
            && (i > board->numMoves - height || ++reps == 2))
            return 1;
    }

    return 0;
}

```

As you can see either `i` must be greater than the root node (i.e. it must come after the root node) or the position *p* needs to be repeated twice (i.e. it must be a threefold repetition) for it to be assigned a draw score.

The chess programming wiki has the following to say about assigning draw score to repetitions:

> Threefold repetition implies a position occurred thrice, that is repeated twice. When to score the position as a draw, however, is an entirely different matter. Most programs do this on the first repetition, no matter whether the first occurrence of the repeated position appears in the current search space, or not. Other programs consider that fact, they avoid cycles inside the current search tree to make it a directed acyclic graph (DAG), but allow a one-fold repetition, if the first occurrence appears in the game history before the current root. Anyway, to wait for the second repetition one has its pros and cons. The Repetition score is either zero or the contempt factor.

It says that “to wait for the second repetition one has its pros and cons.” So, what exactly are the pros and cons? I couldn't find an explanation as to why top chess engines like Stockfish and Ethereal do this.

# Answer
> It says that “to wait for the second repetition one has its pros and cons.” So, what exactly are the pros and cons? I couldn't find an explanation as to why top chess engines like Stockfish and Ethereal do this.

My discussion will be technical, so let's make it as simple as possible. Firstly, let's make be clear about this:

> If the first occurrence of position p is not strictly after the root node then they don't assign a draw score to the twofold repetition.

Why would an engine do that? Let's consider **two scenarios** where we have three-fold repetition during the search. Let's assume we are on move 30th, and the engine is thinking at move 40th.

* The position repeated and played on the board, for example, the position occurred on move 24th and 26th.
* The position **never** actually played on the board, but it is part of the search. The position occurred at move 35th. (IMPORTANT - only a single repetition)

**Scenario 1**

In the first scenario, it's a repetition that we all understand. In your code example:

```
++reps == 2

```

So, if a position repeated twice earlier in the game **before** the root (root == current board position), it's a three-fold repetition. Very simple.

**Scenario 2**

What about the second scenario? You have the identical position on move 35th, and the same position come back on move 40th. Thus, it's reasonable to assume if you search further you will encounter the position again (for the third repetition). For example, move 45th.

Your code example:

```
i > board->numMoves - height

```

> So, what exactly are the pros and cons?

Pros: search quicker and deeper

Cons: you assume the same position would occur again later in the search (e.g. move 45th), which is not always true

> I couldn't find an explanation as to why top chess engines like Stockfish and Ethereal do this.

Search quicker and deeper. Common optimization in modern chess programming.
> 2 votes

# Answer
Looking at some of the forum discussions at the end of the linked chessprogramming.org page, you can see some of the rationale for waiting for the third repetition to consider a position drawn if the first occurrence of the position was before the root.

https://www.stmintz.com/ccc/index.php?id=47672

> My program was playing a game against Greg Kennedy a long time ago, and the following situation occurred.
>
> The program was down two pawns and was completely lost. But Kennedy made a mistake, and my program made a move that won a pawn. At this point the best move from Kennedy's point of view was to undo the move he'd just done. My program's move forced him off of something he was defending, and he had to go back to where he was, and now the program could simply take a pawn that was sitting there for free, vastly improve its chances for a draw.
>
> But that's not what it did. The move it made to win the pawn was also retractable, so it chose to repeat the position, and scored this as 0.00.
>
> Of course, rather than repeating his mistake, Kennedy chose a better move and my program was down two pawns again.

I think this one exemplifies the situation best. In the search, the program assumes that both sides will play the position perfectly. However, this is not the case in real life, especially when a human is involved. As such, reaching a certain position in the past may have been a mistake that should be avoided, and the opponent would likely avoid making that same mistake again if given the opportunity. If the search considers a position drawn on the first repetition, irrespective of whether the position was first reached in the actual game history or in the search, it could miss that the position is actually bad for the opponent and that they would avoid the second repetition.

However, if the repeated position first occurs in the search tree, then it should be safe to assume it as drawn on the first repeat. The search assumes perfect play, so if the first occurrence of the position was not a mistake, and repeating it once is also not a mistake, then three times would not be a mistake either. Perfect play would thus continue on and bring us back to the same position ad infinitum were it not for the three-fold repetition rule.
> 1 votes

# Answer
Let's say your engine sees the best moves in a position as +0.08 and +0.06. It plays the +0.08 move and the opponent replies. In the new position, the engine realizes that it was slightly optimistic, and the best continuation is now +0.01 unless it repeats the position. I think it makes more sense for it to evaluate the repetition as +0.06 than a flat 0. It is, after all, *not* an automatic draw to repeat the position once.

It is, of course, very possible that after the engine repeats and plays the +0.06 move, it will again find that it was optimistic (perhaps for the same general reason) and now the best move is -0.01. Perhaps it now missed its chance to get the +0.01.

So, which scenario is more likely?
> -2 votes

---
Tags: engines, stockfish, programming, draw, threefold-repetition
---


# Question
Title: How to use nodestime option in Stockfish 10?
By looking at the uci option file of Stockfish 10 I found this line:

```
o["nodestime"]             << Option(0, 0, 10000);

```

How exactly does one use nodestime?

# Answer
> 3 votes
> https://github.com/official-stockfish/Stockfish/commit/926f215061311392bc26c7bc4bde5b719dbab4e5

has everything you need. Essentially, it's an option for chess engine testing, not for production use. The option ensures the engine plays perfectly equally during development.

As a user, you shouldn't bother with this option because number of nodes per ms is not something easy to give a value.

# Answer
> 4 votes
The `nodestime` option specifies the amount of nodes searched traded for one millisecond of time.

When the `nodestime` option is set, the engine is limited not by the wall time consumed but by the total amount of nodes searched per game, calculated once per game. The initial time control values are used as source values to be converted to the number of total nodes; however, the source time control settings are not used per turn, but if it were just one turn per game, i.e., the setting of 300 seconds plus 3 seconds increment per move are converted to a total of 303 seconds and then multiplied by `1000 * nodestime`; the result is used as the total number of nodes searched per game. Source: a comment by the Stockfish maintainer.

E.g., suppose you specified `nodestime = 600`, and time control of 300 seconds plus 3 seconds per move (300+3s). In that case, the maximum total number of nodes searched per game by the engine is `303 * 600 * 1000` = `181800000` (one hundred eighty-one million, eight hundred thousand), regardless of how much wall time it will actually take.

However, if you use this option in an engine run from an external time control software, such as `cutechess-cli`, make sure that the engine running on your computer is able to handle that amount of nodes per second (`nodestime*1000`). Suppose that your computer and the engine is able to calculate a maximum 900000 nodes per second. In this case, the maximum reasonable value for `nodestime` is 900, which is 900 nodes per millisecond, or 900000 nodes per second. Otherwise, cutechess-cli will report that your engine lost on time.

---
Tags: stockfish, time-control, time-management
---


title: What are the rules of Shatranj?

text:
# Question
Title: What are the rules of Shatranj?
According to this answer to this question (*Is Chaturanga/Shatranj an early form of chess or is this altogether different?*):

> Chaturanga is the ancient game that gave birth to board games chess, shogi, makruk, xiangqi and janggi. I believe Chaturanga is the same game as Shatranj or got only slightly varied while moved from India to Sassanid Persia.

So, I understand that the earliest form of chess in Persia and the Middle East was called Shatranj and derived from Indian Chaturanga.

What are the rules of this early form of chess?

# Answer
> 5 votes
Summarizing the Wikipedia article, but comparing the differences between regular chess (that seems the most useful to me here):

* Kings don't face each other, the black King starts on d8 and the 'Queen' on e8. Moving is the same, but castling does not exist.
* The Queen (Mantri/Senapati) moves one step diagonally in any direction.
* Bishops move like the Alfil in Arabic chess or some other variation (see the article, but unlike our current bishop).
* The pawns (Padàti/Bhata/Sainik) don't have a double step on the first move (and hence no en-passant).

Further different rules:

> Al-Adli mentions two further rules:
>
> * Stalemate was a win for a stalemated player. This rule appeared again in some medieval chess variants in England c. 1600. According to some sources, there was no stalemate, as the king is forced to move and consequently be captured.
> * The player that is first to bare the opponent's king (i.e. capture all enemy pieces except the king) wins. In shatranj this is also a win, but only if the opponent cannot bare the player's king on his next turn.

As always, treat Wikipedia with a bit of caution; original sources are usually better.

---
Tags: chess-variants, shatranj
---


# Question
Title: What/who are post-game press conferences for?
If you saw the post-game press conference live after round 13 in the Nepo vs. Ding, world chess championship 2023, then you would have seen Nepo getting frustrated about being asked tedious or annoying questions about his choice of shirt and whether or not he is superstitious, and the players being asked if they'll spend a few extra days to teach chess, as if they're not extremely busy, part of a team of people, and don't have flights already booked.

It seems like a much better format would be to simply give the players a board, and ask them to analyze the game. I feel like the players would give more in-depth replies, and a lot of natural questions I would have are "did you see XYZ?" or "why play ABC?", which would get answered this way.

This makes me wonder...

**Question**: What/who are post-game press conferences for?

# Answer
It's for entertainment, plain and simple. (And there are a lot of people entertained by Nepo's shirt choices and superstitions.)

Following serious chess analysis is often too hard for casual fans. If you watch/read coverage of the match you see statements like "Black's compensation is not enough for the pawn", and it's often not apparent to viewers that it is not enough compensation. But going into extreme detail on why Black's compensation is not enough is likely to be too dull for many viewers. In a similar way, we see coverage articles talk about facial expressions and nerves of both players, because those things are easily understood and empathized with.

Just consider, why don't you watch engine chess instead of human chess?

* There's no argument that engine chess is of higher quality than human chess.
* You can get the playing engines to analyze whatever line you want (just play it on your local computer and see what they say).
* You can watch the playing engines analyze in real time. In response to "Did you see XYZ?", you examine their principal variations and see if they saw it.
* If the playing engines didn't see some critical continuation, you can even see them "see it" for the first time, when their evaluation booms or moobs (this is engine chess lingo for "eval explodes away from 0.00" and "eval implodes towards 0.00" respectively).

And yet engine chess fans are maybe 0.1% of the chess community. The "other" World Chess Championship was running at the same time as the World Chess Championship, and yet there was usually no more than a few hundred concurrent viewers. Even during peak engine chess drama (TCEC Season 14 superfinal) there were still no more than a couple thousand viewers. Most people like shirt choices and superstitions. They watch the match for the chess, *and also* for the sporting drama.

PS: Even among engine chess viewers, much of the time, we don't talk about the position on the board and instead talk about the opening books, the scam (e.g. when the engine you want to win somehow fails to convert a winning position), the upcoming elo-gaining patch, and so on. It's a common joke among engine chess fans that we are eval chart watchers. Like the viewers of the post-game press conferences, we are highly interested in things other than the actual chess.
> 6 votes

---
Tags: press-conference
---


# Question
Title: Longest sequence of moves where white's number of available moves decreases
An easier version of this

White has 20 available moves at the start of the game (from the standard position). After 1.h3 h5, white has 19 available moves. (The h pawn has lost the ability to move two squares, the knight can no longer move to h3, and the rook now has one new move, to h2.)

What is the longest sequence of moves whereby white has at least 1 available move fewer than on the previous turn?

# Answer
> 8 votes
It seems to have been missed so far that f3 is also a possible reducing move it gains a king move, but loses both a knight and a pawn move. Therefore, we have a lot more choice and, in fact, a full 20 moves are possible:

```
[FEN ""]

1. a3 a6 2. f3 a5 3. h3 b6 4. b4 a4 5. b5 e6 6. g3 Bb4 7. g4 g5 8. Bg2 Bc3 9. Bf1 Qf6 10. f4 Qxf4 11. Rh2 Qxh2 12. h4 Qxg1 13. h5 Ke7 14. h6 Kf6 15. e3 Bxd2+ 16. Kxd2 Qf2+ 17. Kd3 Qxe3+ 18. Kc4 d5+ 19. Kb4 c5+ 20. bxc6 Qc5#

```

# Answer
> 3 votes
I think I can get 7 moves like this:

```
[FEN ""]
1. h3 h5 2. Rh2 h4 3. a3 a5 4. Ra2 a4 5. f3 c6 6. Kf2 Qb6+ 7. e3 Qxe3+

```
1. h3 h5 (19)
2. Rh2 h4 (18)
3. a3 a5 (17)
4. Ra2 a4 (16)
5. f3 c6 (15)
6. Kf2 Qb6+ (3)
7. e3 Qxe3+ (1)

# Answer
> 2 votes
From the beginning position, in this case only a3 and h3 have a negative effect, and even with swapped colors, the opponent lacks one tempo to capture a rook. A check might be given, thought, thus a sequence might be -20- 1.a3 e6 -19- 2.h3 Qh4 -18- 3.d3 Bb4+ -6- 4.c3 Bxc3+ -4- 5.Nd2 Bxd2+ -3- 6.Qxd2 Qxf2+ -2- 7.Kd1. One move might be addable...Reeeeewan! :-)

# Answer
> 1 votes
I raise the bar to 8 moves, for Hauke.

```
[FEN ""]

1. a3 a5 2. Ra2 a4 3. h3 h5 4. Rh2 h4 5. f3 e6 6. Rh1 Bc5 7. Rh2 Bd4 8. Rh1 Bf2+

```
1. a3 a5: 19
2. Ra2 a4: 18
3. h3 h5: 17
4. Rh2 h4: 16
5. f3 e6: 15
6. Rh1 Bc5: 14
7. Rh2 Bd4: 13
8. Rh1 Bf2+: 1

---
Tags: problems, records, mathematics
---


# Question
Title: When and why should I develop my knight to e2 or f3 in the English Opening?
I have heard that in English opening white should play d4 and Nf3, unless black plays Bc5. In this case white plays d3 and Ne2 in order to block the black bishop. However, that lesson seems to be fairly amateur, since Stockfish disregards this advice. For example, in this position it says that 6.Nf3 is better, while 6.Ne2 is not even in the top three (to let alone the fact it says 4.e3 is bad for some reason).

```
[FEN ""]

1. c4 e5 2. g3 Nf6 3. Bg2 Bc5 4. e3 d5 5. cxd5 Nxd5

```

While if black plays 4...O-O, then 5. Ne2 is still the best.

```
[FEN ""]
1. c4 e5 2. g3 Nf6 3. Bg2 Bc5 4. e3 O-O

```

Is there any logical explanation to it or is it those opening subtleties the engine is too captious at?

# Answer
> 0 votes
> When and why should I develop my knight to e2 or f3 in the English Opening?

The two moves have different advantages and disadvantages. Which one you choose depends primarily on your plans.

**Nf3**

1. Puts more pressure on the center and e5
2. Might be vulnerable later on to a pin from a bishop on g4

**Ne2**

1. Prepares the f4 pawn push
2. Can't be kicked by the black advance e4

As with all openings, to get a good position you need to know what plans you are going to try and implement and choose your moves accordingly.

---
Tags: opening, engines, knights, english-opening, development
---


title: Roundtrips with no shortcuts

text:
# Question
Title: Roundtrips with no shortcuts
In the picture, you see the longest roundtrip of a rook such that there are no "shortcuts" - imagine the target squares are given, then at each square you have exactly two other given squares accessible to the rook, and they connect to a round trip. (Trivially the longest rook trip length is 2\*8.)

What are the values for the other officers? Q and N are most interesting. (I think I know the maximum for N.)

Note: a1-b1-c1 is forbidden, even if you can't go from a1 to c1 if something stands on b1.

Son of Note: You *could* formulate this problem far simpler: "Place m queens (knights,...) such that all queens are protected twice". But it's not the same problem anymore - the Qa6 will never "touch" Qh3.

# Answer
> 1 votes
Here are my attempts for Q and N.

Observe that I didn't use g&h at all, maybe 11 are possible after all.

---
Tags: problems, records, mathematics
---


# Question
Title: Longest sequence of moves where number of available moves increases
White has 20 available moves at the start of the game. After 1.a4 e5, white has 21 available moves. (The rook has gained 2 moves, while the pawn has lost 1).

What is the longest sequence of moves whereby white has at least 1 more available move than they had the previous turn, starting from the starting positon? The possibility of pawn promotion counts as four separate moves.

# Answer
> 4 votes
EDIT: Old version below, this is a new improved version. If you have suggestions for a better final position to aim for, that allows for more White legal moves and might be reachable through this constraint, please let me know in the comments. For now I have given up on finding something better.

```
[FEN ""]

1. g4 b6 2. h4 e6 3. b4 Be7 4. Nh3 a5 5. f4 e5 6. c3 h6 7. Bb2 Bb7 8. Na3 e4 9. Nf2 Bc8 10. h5 Bc5 11. Rg1 g6 12. Qb1 e3 13. g5 Bd4 14. c4 d5 15. Bh3 Bf5 16. dxe3 Bc2 17. Kf1 Bd3 18. exd3 Bg7 19. Nb5 Bc3 20. a4 c5 21. Ba3 Bf6 22. Bf5 Qc7 23. Nc3 Bg7 24. Rg2 Qe5 25. Qa2 Qe7 26. Qb2 Qd6 27. Rc1 Bf6 28. Rg1 Qe5 29. Nfe4 Bg7 30. Be6 Qc7 31. Ke2 Kf8 32. d4 Ra7 33. Ra1 Nd7 34. Rh1 Ke7 35. Kf2 Qb8 36. gxh6 Rh7 37. Ke2 Qe5 38. hxg6 Qg5 39. Nd6 Qf6 40. e4 Nb8 41. Kf2 Nd7 42. Kf3 Bh8 43. Qf2 Qh4 44. Qe2 Qf6 45. Ke3 Ne5 46. g7 Rc7 47. Qc2 Ng6 48. e5 Qh4 49. Rhg1 Rc6 50. bxa5 Rc7 51. Bc8 f6 52. dxc5 Qg5 53. Bh3 Kd8 54. cxd5 N6e7 55. a6 Rb7 56. a5 Rb8 57. a7 Qg4 58. f5 Qg6 59. gxh8=Q Rg7 60. h7 Kd7 61. Rab1 Nc8 62. exf6 Nge7 63. Rb4 Rb7 64. cxb6 Rb8 65. b7 Nb6 66. a6 Rc8 67. Qf8 Rd8 68. h8=Q Rg8 69. fxe7 Qg4 70. f6 Rc8 71. b8=Q Rc6 72. dxc6+ Ke6 73. Kd2 Qf5 74. c7 Rg7 75. Qfd8 Nd7 76. f7 Kf6 77. Qh5 Rg5 78. Rc4 Kg7 79. Ke3 Nf8 80. Qxg5+ Kh8 81. Qe4 Qd5 82. Ndb5 Qa8 83. Re1 Qc6 84. Rf1 Qa8 85. Be6 Qc6 86. Ke2 Qa8 87. Bb2 Qc6 88. Ba3 Qb6 89. Qdd3 Qg1 90. Nb1 Qb6 91. Qeg2 Qc5 92. Ra4 Qg1 93. Kd2 Qh1 94. Qb6 Nd7 95. Bb4 Nf6 96. Ba3 Nh5 97. Qbc6 Nf6 98. N1c3 Ne8 99. a8=Q Qg1 100. a7 Qh1 101. Ke1 Qh2 102. Qcd6 Qh5 103. Rf2 Qh2 104. Q2g4 Qh7 105. Bc8 Qg8 106. Bc5 Ng7 107. Qgg2 Qd8 108. Rff4 Ne8 109. Qge5+ Ng7 110. Bg4 Qg8 111. Qac6 Qb8 112. Qdf6 Qg8 113. Kf1 Qb8 114. Na2 Qd8 115. Kg1 Qb8 116. Be6 Qd8 117. Ba3 Qb8 118. Qfg5 Qd8 119. Bg4 Qb8 120. Qgg6 Qd8 121. Qgd2 Qb8 122. Qf2 Qd8 123. Bd1 Qb8 124. Qg4 Qd8 125. c8=Q Qe8 126. Qge6 Qg8 127. Qeb3 Qd8 128. Qfg3 Qg8 129. Qgg2 Qd8 130. Kh1 Qg8 131. Nc7 Qe8 132. Qbb2 Qf8 133. Ne6 Qg8 134. Qbb6 Qd8 135. Rg4 Qg8 136. Qgf2 Qe8 137. Rg6 Qd8 138. Q6d7 Qg8 139. Q7d5 Kh7 140. Qdb7 Nh5 141. e8=Q Nf6 142. Qcc4 Kh8 143. Kh2 Kh7 144. Nc1 Nh5 145. Be7 Ng3 146. Qcc2 Nh1 147. Qcc3 Qh8 148. Qcd2 Qg8 149. Qec8 Qe8 150. Q7c6 Qh8 151. Qcb8 Qg8 152. Qbb1 Qe8 153. Qdf1 Qg8 154. Qfe3 Qh8 155. Qef5 Qg8 156. Q1b2 Qe8 157. Ng7 Qg8 158. a8=Q Kh8 159. Ne8+ Kh7 160. Qaa7 Ng3 161. Qac7 Nh5 162. Q7d7 Ng7 163. Qde1 Nh5 164. Qh4 Qh8 165. Qcd5 Qg8 166. Qdc7 Qh8 167. Ng7 Qe8 168. Raa6 Qg8 169. Nxh5 Qe8 170. f8=Q Qf7 171. Q8b4 Qe8 172. Ra8 Qd7 173. Qe8 Qa4 174. Qeb5 Qa1 175. Qa6 Qa4 176. Bf8+ Qd7 177. Ba4 Qf7 178. Bg7 Qf8 179. Rb8 Qe8 180. Nb3 Qg8 181. Na5 Qe8 182. Qba1 Qh8 183. Qfc2 Qg8 184. Bd7 Qf7 185. Re8 Qf8 186. Nb7 Qg8 187. Nd8 Qf8 188. Nf7 Qe7 189. Nh6 Qd8 190. Kg1 Qb8 191. Bh8 Qc8 192. Rf8 Qd8 193. Kg2 Qb8 194. Kh1 Qa7 195. Kg1 Qa8

```

*Previous version:*

And here is a more serious attempt, managing to promote all 8 pawns. In particular every pair of half moves adds exactly one more legal move:

```
[fen ""]
1. b3 d5 2. f4 g5 3. c4 Bh6 4. b4 Bh3 5. a4 b5 6. Ra2 f5 7. g3 e5 8. Ra3 Na6 9. Rd3 Bg2 10. Na3 Bf3 11. Rc3 Nc5 12. e4 d4 13. d3 Bg2 14. h3 Qd5 15. Qc2 Bg7 16. Qe2 Nf6 17. Be3 Kf8 18. Kd1 h6 19. Qb2 Qc6 20. g4 Nh5 21. Ke1 Qd5 22. Rh2 a5 23. h4 Ng3 24. Nf3 Qb7 25. Ng1 Bf3 26. Rc1 Nb3 27. h5 Qd5 28. Ra1 Bh1 29. Rd1 Nc5 30. Nf3 Ne2 31. Qa2 Ng1 32. Rc1 c6 33. Qb2 Kf7 34. bxa5 Bf8 35. Ra1 Nb7 36. Kd1 Rb8 37. a6 Nd8 38. Qb4 Ke6 39. Raa2 Qd7 40. a7 Bg2 41. Nb1 Qf7 42. c5 Bh3 43. Qc3 Qf6 44. Na3 Qg6 45. Nb1 Bd6 46. axb8=Q Rf8 47. Qa5 Nf7 48. Qc3 Ke7 49. Qa8 Rh8 50. Qc8 Qh7 51. Qd8+ Ke6 52. Na3 Qg6 53. Nc4 Re8 54. Rab2 Rh8 55. Rb1 Bb8 56. Ra2 Rh7 57. hxg6 Bc7 58. Bf2 Bb6 59. Be3 Ba7 60. g7 Bb6 61. Rb3 Rh8 62. Rb1 Bg2 63. Bf2 h5 64. Bg3 Nh3 65. Bf2 Bh1 66. Be3 Ba7 67. axb5 Rf8 68. Nb6 Nh8 69. Qd6+ Kf7 70. Nc4 Bb6 71. Qd7+ Kf6 72. g8=Q Rd8 73. Qc7 Rd6 74. Qe8 Ba7 75. bxc6 Rd5 76. Qb7 Rd6 77. c7 Re6 78. Bg1 Rd6 79. Be3 Rd5 80. Ke1 Bb8 81. Qb6+ Kg7 82. Qbe6 h4 83. Kd1 Bg2 84. Rb7 Bh1 85. Rb1 Kh7 86. Qf8 Rd8 87. cxb8=Q Rd7 88. Qff6 Rd5 89. Qee8 Rd8 90. Bg1 Rd5 91. exd5 e4 92. dxe4 Ng6 93. Qee7+ Kh6 94. c6 d3 95. Qff7 Nh8 96. Qfg8 Ng6 97. Bf2 Nh8 98. exf5 d2 99. Kxd2 Ng1 100. Bg2 Ng6 101. Nxg5 Nh8 102. Kd3 Nh3 103. Nf3 Nf7 104. c7 Nd8 105. cxd8=Q Ng1 106. Qgf7 Nh3 107. Qdd7 Ng5 108. Qfg8 Ne6 109. Qda7 Nf8 110. Ke2 Ne6 111. Qa4 Ng5 112. Nh2 Nh7 113. Qc6+ Nf6 114. d6 Nh5 115. d7+ Nf6 116. Qca8 Nh5 117. d8=Q Nf6 118. Rc2 Nh5 119. Qaa7 h3 120. Qdd5 Ng7 121. Qbc8 Ne8 122. Ra2 Nd6 123. Qa4 Ne4 124. Nf3 Ng5 125. Nd6 h2 126. Ne4 Nf7 127. Q8c7 Ng5 128. Ng3 Nh7 129. Qcb8 Nf8 130. f6 Ng6 131. Qa6 Nh4 132. Qh8+ Kg6 133. Ng5 Nf5 134. Qa4 Ng7 135. f7 Nh5 136. f8=Q Ng7 137. Rab2 Nf5 138. Qfc8 Ng7 139. Rxh1 Ne8 140. Rbb1 Nd6 141. Nf5 Nc4 142. Nf3 Ne3 143. Bh3 Ng2 144. Nh6 Nh4 145. g5 Kh5 146. Qb6 Nf5 147. Bg3 Ne3 148. f5 Nc2 149. f6 Na3 150. Qhh7 Nc2 151. Qhe4 Na3 152. f7 Nc2 153. Rb2 Na1 154. f8=Q Nc2 155. Rg1 Ne3 156. Qb1 Ng2 157. Qff6 Ne3 158. Qff4 Nf1 159. Rd2 Ne3 160. Ra2 Nf1 161. Bh4 Ne3 162. g6+ Nf5 163. Ng5 Nd6 164. Rg2 Nb7 165. Rxh2 Nd8 166. Kf1 Nb7 167. Rae2 Na5 168. g7 Nb7 169. Kg2 Na5 170. Rh1 Nb3 171. Kf2 Na5 172. g8=Q Nb3 173. Qgh8 Nd2 174. Qhh7 Nf1 175. Kg2 Nd2 176. Qhh8 Nc4 177. Qcb8 Na5 178. Bf5 Nb7 179. Qbc8 Na5 180. Bh7 Nb3 181. Qhf8 Na5 182. Qfg7 Nb7 183. Ng4 Nd8 184. Qh8 Nf7 185. Qhg8 Nh6 186. Qgg7 Ng8 187. Qh8 Nh6

```

# Answer
> 3 votes
Here's a first attempt of mine:

```
[FEN ""]

1. b3 a6 2. g3 a5 3. b4 b6 4. c3 c6 5. c4 b5 6. bxa5 d5 7. g4 f5 8. a6 h5 9. a7 d4 10. axb8=R Kd7 11. cxb5 Ba6 12. bxa6 g5 13. gxf5 Qc7 14. f6 Kd6 15. f3 Bg7 16. Kf2 h4 17. fxe7 Kc5 18. Ke1 Bf8 19. Kf2 Rxa6 20. e8=Q h3 21. d3 Ne7 22. a3 Ng6 23. Ke1 Nh4 24. Kf2 Kd6 25. Ke1 g4 26. Kf2 gxf3 27. Ke1 fxe2 28. Kf2 Nf3 29. Kxf3 e1=R 30. Kf4 Ra4 31. Kf3 Rxa3 32. Kf2 Rxa1 33. Kg3 Ra3 34. Kf2 c5 35. Kg3 c4 36. Kf2 cxd3 37. Kg3 Ra1 38. Kf2 Bh6 39. Kg3 Bg7 40. Kg4 Rg8 41. Na3 Rb1 42. Nf3 Kc5 43. Nxb1 Kd6 44. Na3 Qc3 45. Nxd4 Rh8 46. Kg3 Kc5 47. Kg4 Rg8 48. Nc4 Rf8 49. Kxh3 Rf2 50. Kg3 Rexf1 51. Kh4 Kd5 52. Bd2 Qb2 53. Nd6 Qa1 54. Rxf1 Kc5 55. Kh3 Rf5 56. Kg2 Qb1 57. Kg3 Rf6 58. Kg2 Qa1 59. Bg5 Rf5 60. Kg3 Rf8 61. Nc4 Kd5 62. Bd2 Rg8 63. Bg5 d2 64. Rf2 Rh8 65. Kg2 Bh6 66. Kg3 Kc5 67. Rf6 Qb1 68. Kg2 Qa1 69. Bxd2 Bg7 70. h4 Kd5 71. Rb3 Bf8 72. Bf4 Kc5 73. Nc2 Qc1 74. Kf2 Bh6 75. Kg2 Bg5 76. Kf2 Qb1 77. Kg2 Qa1 78. Ra6 Bd8 79. Kf2 Bf6 80. Qed7 Bg5 81. Be5 Rh6 82. Qf3 Bc1 83. Kg1 Rh8 84. Rb8 Qa4 85. h5 Qa2 86. h6 Qa1 87. h7 Rf8 88. Kf2 Rg8 89. Ke1 Qa2 90. Kf1 Bg5 91. hxg8=R Be7 92. Rh6 Bd8 93. Ke1 Bc7 94. Rb3 Bb8 95. Rbxb8 Qa3 96. Rb1 Qa6 97. Kd2 Qb7 98. Ra1 Qa8 99. Nb4 Qa7 100. Kc2 Qa6 101. Rag1 Qa5 102. Ra1 Qa8

```

Which, incidentally, breaks the supposed 100 move barrier. :)

# Answer
> 1 votes
Here is my starting bid of **48 moves**.

```
[FEN ""]

1. b4 Nc6 2. b5 Nf6 3. b6 d6 4. g4 Rg8 5. g5 Rh8 6. g6 Rg8 7. gxh7 Ne4 8. bxa7 Rb8 9. a4 e6 10. a5 Bd7 11. a6 Be7 12. axb7 Ra8 13. h4 Nf6 14. h5 Ne4 15. h6 Ng5 16. hxg7 Rh8 17. c4 Rg8 18. f4 Rh8 19. d4 Rg8 20. e4 Rh8 21. f5 Rg8 22. c5 Rh8 23. d5 Rg8 24. e5 Ne4 25. cxd6 Rh8 26. dxc7 Rg8 27. dxc6 Nc5 28. Kf2 Rh8 29. Qc2 Rg8 30. fxe6 Rh8 31. Rh2 Rg8 32. Rh5 Rh8 33. Rh4 Qc8 34. Ra5 Bd8 35. Raa4 f6 36. exf6 Rg8 37. e7 Rh8 38. cxd7+ Kf7 39. Nf3 Ke6 40. Kg3 Kd6 41. f7 Kc6 42. gxh8=Q Kb6 43. Qhb2+ Kc6 44. e8=R Kd5 45. Re6 Be7 46. f8=Q Bg5 47. Bxg5 Na6 48. h8=Q Nb8

```

---
Tags: problems, records, mathematics
---


# Question
Title: Is there a Chess 960 position in which White's moves can be decreased to zero without check?
Inspired by this question, koedem proved that, from the starting position, White's legal move amount can be decreased sequentially from 20 to 0 in 20 moves. However, doing so required some checks. I wondered if doing so was possible without check.

In experimenting, I found a method to up the starting position to reduce to five legal moves without utilizing check.

```
[FEN ""]

1. a3 a6 2. f3 a5 3. h3 b6 4. b4 a4 5. b5 e5 6. g3 Bb4 7. g4 g5 8. Bg2 Bc3 9. Bf1 Qf6 10. f4 Qxf4 11. Rh2 Qxh2 12. h4 Qxg1 13. h5 d6 14. h6 Bxg4 15. e4 Bxd1

```

But I highly doubt that it is possible from the normal starting position (but is may be possible, I just think it unlikely; if so, it still counts as a valid answer). Is it possible in a Chess 960 position?

# Answer
> 2 votes
This is in fact possible in standard chess. I have found multiple possibilities in each of the following scenarios, so neither puzzle has a "unique" answer.

Here is one that ends in checkmate:

```
[FEN ""]

1. a3 Nc6 2. Nh3 Nd4 3. b4 b5 4. Rg1 e5 5. Nf4 exf4 6. h4 Bxb4 7. Ra2 Qxh4 8. Rb2 Qg3 9. Nc3 Bxc3 10. a4 Bxb2 11. c4 bxc4 12. Qb3 cxb3 13. a5 Bxc1 14. d3 f5 15. e3 fxe3 16. a6 Bb2 17. Kd1 exf2 18. Kd2 fxg1=Q 19. Be2 Q1f2 20. Kd1 Qxe2#

```

And here one that - more in the spirit of the question - ends in stalemate:

```
[FEN ""]

1. a3 Nc6 2. Nh3 Nd4 3. b4 b5 4. Rg1 e5 5. Nf4 exf4 6. h4 Bxb4 7. Ra2 Qxh4 8. Rb2 Qg3 9. Nc3 Bxc3 10. a4 Bxb2 11. c4 bxc4 12. Qb3 cxb3 13. a5 Bxc1 14. d3 f5 15. e3 fxe3 16. a6 Bb2 17. Kd1 exf2 18. Kd2 fxg1=Q 19. Kd1 Bxa6 20. Kd2 Qxf1

```

---
Tags: problems, records, mathematics, chess960
---


title: Are Nalimov tables still being built?

text:
# Question
Title: Are Nalimov tables still being built?
The Nalimov/Syzygy, etc tablebases are, as far as I know, computer databases that store all the possible possitions in the board, with the best moves and the outcome of the game, assumming both players work perfectly.

Is there still work on them? I think all the positions of 7 or less pieces are solved by now, but I don't know if there are computers out there at the moment, calculating positions and adding them to these databases.

# Answer
Certainly there is work on 8-man tablebases.

One source of information on this is from the Chess Endgame Study Association here This article describes pawnless ending work.

It is simpler to start with pawnless endings as there are fewer possible positions to evaluate. And evaluating all endings with pawns depends on evaluating the pawnless ending that occur after promotion.

Chessbase has this article that re-evaluates some known positions using this research.
> 9 votes

---
Tags: tablebases
---


title: Le Petit Tourette

text:
# Question
Title: Le Petit Tourette
A kid I occasionally see on tournaments has a tic - he makes compulsive noises. Kids obviously have more understanding of such stuff - noone ever complained about being disturbed or made any ado about it at all.

Now, if he will play adult tourneys in a few years. Hmm. Should I ever play him, well, I could care less about the BBC Big Band Orchestra marching through the tournament hall, but others are easily disturbed.

What would you do as an arbiter? (The question of course generalizes to a bad cough or likewise any potential disturbance a player can neither control nor turn off.)

# Answer
Article 12 of the FIDE Laws of Chess defines the role of the arbiter. 12.2 specifies the things that the arbiter shall do and in particular:

> 12.2.6 take special measures in the interests of disabled players and those who need medical attention

FIDE makes every effort to encourage and facilitate the fullest participation of players with disabilities and requires that its arbiters do likewise.

If you have ever played with or against a blind player you will know that they call out their moves, their opponents are required to do likewise and then they usually speak the opponent's moves into a recording device. Hence the concept of a player with a disability making noises that would not be acceptable in player without disability should be familiar to all arbiters.

I have arbited in an open tournament with players rated 1900 - 2400 where one of the players had a nervous twitch every couple of seconds. Everybody in the tournament understood that this was a disability and nobody said anything. Obviously, nor did I.

I would expect exactly the same to apply to a player with the disability you describe.
> 3 votes

---
Tags: rules, etiquette
---


# Question
Title: What are good books on the Panov-Botvinnik Attack and playing with an IQP?
Respectively, what are good books for the Panov-Botvinnik Attack and playing with an isolated queen pawn?

# Answer
For Isolated Queen Pawn play I would pick up a pawn structure book. They typically start off with IQP. Most of the game examples will be Queen's Gambit, but the beauty of a pawn structure approach is that it applies independent of opening. It's worth studying pawn structures generally once you are not dropping pieces regularly as strategy becomes more important.

Two best books in English (Opinion)

* Pawn Structure Chess - Andrew Soltis
* Chess Structures A grandmasters guide - Mauricio Flores Rios
> 5 votes

# Answer
Ivan Sokolov's book, Winning Chess Middlegames, is all about pawn structures. He devotes one 94-page long chapter to playing with and against an isolated queen's pawn and then another 42-page long chapter to hanging pawns, which is what isolated queen's pawn positions often turn into. It's an excellent and instructive book.
> 1 votes

---
Tags: opening, books, caro-kann, recommendations, isolated-pawn
---


# Question
Title: Can Nepo and Ding receive computer analysis from teammates between tiebreak rounds?
In round 4 of the tiebreaks for the 2023 world championship (LiChess), Nepo played the surprise 13.Bb1. I'm wondering if Nepo's teammates may have done a computer analysis of this position, which also occurred in round 2, and communicated to this to Nepo between rounds (during rest time). I'm not sure if this is allowed.

**Question**: Can Nepo and Ding receive computer analysis from teammates between tiebreak rounds?

# Answer
> 8 votes
Very likely **no**, notwithstanding any fairness issues of allowing communication after the round starts, the regulations of the 2023 FIDE World Championship state:

> **4. 10. 2.** Except with the permission of the Chief Arbiter, only the players, the FIDE principals, one media professional from the organising team, and stewards are allowed in the playing area. **The players may communicate with an arbiter or a steward.**

This implies that to get external analysis, they would need to leave the playing venue.

This sounds impossible as the inter-round time is 10 minutes, this would have been contrary to the playing venue rules to step out and back in that timeframe :

> **4. 10. 4.** The players shall arrive at the playing area at least ten minutes before the beginning of the game for the security check.

---
Tags: rules, tournament, world-championship
---


# Question
Title: How is white allowed to castle 0-0-0 in this position?
I always thought the rules are you can’t castle if an enemy piece is watching the space between your king and the rook you want to castle with. But according to chess.com castling long is allowed in the following position

# Answer
> 21 votes
You can not castle if your king would start, move through or end in check. For short castling that amounts to the same, since the corresponding squares e1, f1 and g1 include all the squares between king and rook. (Note that you can short castle even if your rook is attacked.)

For long castling that makes a difference since b1 as in this example may be attacked but the White king never crosses that square.

For reference: https://www.fide.com/FIDE/handbook/LawsOfChess.pdf Article 3.8 b.2.a:

> Castling is prevented temporarily:
>
> \[a\] if the square on which the king stands, or the square which it must cross, or the square which it is to occupy, is attacked by one or more of the opponent's pieces

# Answer
> 2 votes
Basically, if there is none of the opponent active pieces threatening c1, d1, or e1 (the king can't be in check), then the king can castle long, as long as the king hasn't moved yet. Well, the rook has to have stayed in its original position as well. The same can be said for e1, f1, g1 when it comes to castling the other way.

# Answer
> 2 votes
Castling is only prevented when the king ends, goes through, or is currently in check or when the king or castle has already moved. Since the king doesn't go through b1 castling is allowed.

---
Tags: rules, castling
---


# Question
Title: Why are players required to record the moves in World Championship Classical games?
I understand that in some lower-level games, if the players do not record the moves, nobody else will do it for them. But what is the point of requiring the players at World Championship classical games to record the moves? After all, they can easily hire somebody else to do the job and let the players just focus on making the moves.

# Answer
> 22 votes
To my understanding there are a few reasons to require the players to record the moves. However, I believe that most of them could also be solved with a sufficient technological investment.

* **Tradition**: Chess has a rich history, and recording moves has been a part of the game for centuries. This tradition is preserved at the highest level to honor the game's roots and maintain continuity.
* **Move Number Recording**: A technical reason is that the players can easily keep track of the move number themselves that way, so that they know when they get the additional time at moves 40 and 60. The same argument could be made for three-fold repetition, which needs to be claimed instead of automatically taking effect, but I would suggest that it is not that easy to see from the record sheet.
* **Legal Record Keeping**: The fact that the physical record is signed by each party at the end gives it the semblance of a legal contract, which gives the players a sense of responsibility and fair play, although that argument is clearly weaker at the championship level, where this would be taken for granted anyway.
* **Tier System Avoidance**: At some level of professional play, the record keeping rule would need to be relaxed, introducing a tiered system, where one tier has to keep physical records and the other one does not. In general, many professional tournaments could then also relax the record keeping requirement, but at which level exactly would you then drop the requirement. Should the Candidates tournament, which is also very prestigious, drop the requirement? I think that ambiguity goes a long way in explaining the requirement.

I do not think that there are any technical reasons for maintaining the record keeping requirement. However, the sociological and convenience reasons lined out above probably pushed the arguments in favor of not dropping the record keeping requirement even for the world championship.

# Answer
> 4 votes
In addition to the answer already given, I would add:

To provide a paper-trail in case confusion or disputes arise.

There have been many cases of illegal moves or disputed moves during top-level play, especially involving the touch-move rule or during time pressure. For instance, the Kasparov touch-move incident against Polgar during the 1994 Linares tournament was a famous top-level incident.

In such cases, it can be helpful to have documentation of the game so far, according to the players themselves. Consider a situation where a piece is placed on the border between two squares, and a dispute arises between the players as to which square the piece was moved to. Having the players themselves document which square the piece was moved to provides a canonical record of the moves, which wouldn't otherwise exist.

This documentation is of peak importance in the highest-stakes games, where accurate arbitration of disputes is essential.

---
Tags: world-championship, notation
---


# Question
Title: What color squares should pawns be on with one bishop left?
This slightly confuses me. If I have one bishop left - let's say it is the light-squared bishop - ss it better for my pawns to be on the light squares or dark squares? Let's assume also that my opponent has a dark-squared bishop. The way I look at it it is like this (which is probably wrong). If my pawns are on the light squares, I can protect them with my bishop, but they block my bishop. If my pawns are on the dark squares, they don't block my bishop, but I can't protect them.

Does it make a difference if the opponent has a bishop left that is the same color as yours, or has no bishop left?

# Answer
The rule of thumb is that the stronger side (the side trying to win) should put the pawns on the opposite color of his or her bishop (so that they don't get in the way), and the weaker side should put pawns on the same color as their bishop in order to defend them an extra time (defended with the bishop and the king, the opponent can never win a pawn).

There are obviously exceptions to this, though. Each position really has to be judged independently.

One key idea, however, is that it is usually a good idea to block your opponent's pawns on the same color as the bishops (assuming that the two bishops are both light squared bishops or both dark squared bishops). This gives you the chance to try and win the pawn later and it will restrict the movement of your opponent's bishop.

If you have the only bishop on the board (your opponent has a knight, for example) it is almost always correct to put the pawns on the opposite colored squares of the bishop. This is usually the only way to play for a win. This touches on the good bishop/bad bishop question, but if your bishop is bad, then the knight will many times have the edge. If your bishop is good, however, you can try to make use of the bishop's superior range.
> 14 votes

# Answer
With a light squared bishop, you (usually) want your pawns to be on *opposite* colored squares, i.e. the dark squares. This is particularly true because the opposing bishop is dark squared.

The pawns are supposed to protect *each other* (on dark squares). In doing so, they block the opposing bishop. Your bishop is supposed to "cover" those (light) squares not protected by your pawns.

If both your bishop and pawns are on light squares, the opposing king (and bishop) will be able to run all over the dark squares. Meanwhile, the pawns are in the way of your own bishop. This will put you at a severe disadvantage.
> 3 votes

# Answer
Well, it may be irrelevant to answer an 11-year-old question, but there's still a thing not mentioned in previous answers.

In an opposite-colored bishop endgame (i.e. when both you and your opponent have only a king, a single bishop and pawns (no knights, rooks etc.), and your bishops travel on opposite colors), it depends on whether you are attacking or defending side.

When you are the attacking side (i.e. having chances to win), it's still better to place your pawns on opposite color of your bishop (i.e. the same color as your opponent's bishop), since otherwise your pawns can be blockaded and cannot cross a diagonal which is firmly controlled by your opponent (usually by both his king and bishop). (For example, white pawns on the light squares g6, f5 and e4 can be blocked with the black dark-squared bishop along the a1-h8 diagonal.)

*But, if you have to defend*, it's often better to go the other way round, namely placing your pawns on the same color as your bishop. That's because your remaining pawns are easier to be protected (with your bishop), and they are invulnerable to both the opponent's bishop (traveling on opposite color) and his king (since he cannot capture protected pieces).

Of course, there are exceptions to this rule of thumb, but it holds in many positions.
> 1 votes

---
Tags: strategy, endgame, bishops, positional-play, bad-bishop
---


# Question
Title: Is 2. c3 the best response against the Caro-Kann?
On chess.com, I was playing as White and my opponent played the Caro-Kann. I personally like the accelerated Panov Attack, 2. c4, but my mouse slipped and I played 2. c3. I was very mad when I did this, but later when I was analyzing, Stockfish said that this is actually the best move. Here is m y own analysis (the engine only says "Yes! This is the way!"):

* It opens a diagonal for the queen.
* It prepares 3. d4 on the next move, allowing the knight to move to d2.
* The annoying bishop pins that usually happen when the knight is on c3 can't happen anymore.

Are there any other reasons why 2. c3 is the best move?

Here is the link to my game.

# Answer
It is a solid move but not the strongest. For example, if Black continues with 2... d5, and White plays 3. e5 in the spirit of the advance variation, we reach by transposition a position that would be the same as if White played 4. c3 in the main line of the advance variation (see below the variations). Instead of 4. c3, sharper lines include 4. h4 or 4. c4, which also have better engine assessment. What I find interesting about 2.c3 move is that

1. may come as a surprise for your opponent, who will try to understand any move order nuances.
2. allows 3. exd5 going into the exchange variation (see variation below), and thus it is a flexible move.

.

```
[Title ""]
[fen ""]
[Startply "21"]

1. e4 c6 2. c3 (2. d4 d5 3. e5 (3. exd5 cxd5 4. c3) 3... Bf5 4. c3 (4. h4)) 2... d5 3. e5 (3. exd5 cxd5 4. d4) 3... Bf5 4. d4 e6

```
> 5 votes

# Answer
I doubt that it is the best move. The pawn on c3 is an early committment, i.e. it does something now that is irreversible but only in some lines useful. Neither Stockfish nor Leela suggest this move as their first choice. In addition, Black wins about 51 percent of games with 2.c3 on the lichess database. While this last bit of evidence is likely partly explained by other factors than the move being *bad* (I don't think White is already at a disadvantage here), the sum total of all of these points make it very unlikely that 2.c3 is an objectively good move here.

As I said, however, White is probably not at a disadvantage after that move. In that spirit, one could consider playing it as a means to get Black out of book, maybe with a view to making them overplay in an attempt to "punish" the deviation from established theory. This might work, but I would feel that the move transposes easily enough to known lines for this not to be a major issue for Black here.
> 5 votes

# Answer
In an analysis board, if you click on the settings icon (should be right above the h8-square), see what's selected for Strength. If it's on 'Fast', this would explain why 2.c3 is ranked as the top move. The Fast setting only lets the engine think for 1 second, which isn't very much. This is especially so given the fact that chess.com says depth 14 takes ~3 seconds, depth 20 takes ~30 seconds, etc. This is extremely slow by engine standards (e.g., in ChessBase, ~3 seconds takes Stockfish 15 to depth 22-24). I imagine it's so slow on chess.com since a .js or .wasm version of stockfish has to run on the client-side. This is super slow compared to the standard C++ executable of Stockfish that runs locally in a program like ChessBase.
> 2 votes

# Answer
No, it is not the strongest. My answer will explain why this happened to you and how we know it is wrong. First of all, Chess.Com uses Komodo, not Stockfish. Komodo is significantly weaker. Stockfish disagrees and goes for d4. Komodo did still hold by its anylysis in a game I played against it though. The other answers have explained sufficently why other moves are stronger. Note that I ran Stockfish 16.1 at Depth 25 on a 16 CPU Core.
> 1 votes

---
Tags: opening, analysis, strategy, caro-kann
---


# Question
Title: How to avoid QGD/Slav lines as black against 1.d4?
I have come to be a bit sick of Queen's Gambit Declined/Slav Defense type positions as black. But I struggle to find anything to play against 1.d4 which doesn't soon transpose into that.

It seems difficult to avoid playing ..d5 in one of the first moves, because without it, Nc6 is met by d5. And as soon as ..d5 is played by black, c5 comes, and there we go again.

What are some interesting alternatives? I'm around 1600 on Lichess, so dubious, dynamic openings are just fine by me.

# Answer
The King's Indian Defence is the first thing that comes to my mind. You'll have to like the pawn structures that arise from e.g. the Main line, with White trying to break through on the queenside while Black is mounting a king attack; computers often give a pawn or so advantage to White, but Black's chances are much better than that. But it's definitely different than the QGD structures you don't like, even if White tries to sidestep with e.g. the Exchange variation or the Sämisch.

Another alternative would be the Dutch defence, especially the Leningrad variation with ...g6. It may be a bit dubious at master level but perfectly playable for you and me.
> 7 votes

# Answer
A few choices where White will have it hard to get into a QGD-like position:

* King's Indian: probably the "obvious" choice.
* Queen's Gambit Accepted: use the time your opponent loses recapturing the pawn to strike back in the center (for example **1.d4 d5 2.c4 dxc4 3.e4 e5!?** or **3.Nf3 Ng6 4.e3 c5!?**)
* Grünfeld Defense: you also get a d4-vs-d5 type of center in the lines where White doesn't take on d5 (after **1.d4 Nf6 2.c4 g6 3.Nc3 d5**) but it usually ends up getting liquidated early on.
* Dutch Defense. many interesting lines to choose from, each leaving you with different types of positions. From the more dynamic Leningrad to the stalest Stonewall.
* Old Indian: similar themes to the King's Indian but in less-known territory.

But you can also go for lines that try to conquer your fears! After all, if your issue is what to do about the knight on b8, there are several solutions!

* The Nimzo-Indian is a way to keep your options flexible before deciding if you want to play ...d5 or go for something else instead depending on how your opponent sets up. After **1.d4 Nf6 2.c4 e6 3.Nc3 Bb4**, depending on White's next move you'll be able to choose between ...0-0, ...d5, ...d6, ...c5 and ...b6, before or after taking the knight
* The Tarrasch Defense is probably the most active way to play the QGD, striking early on c5 so you don't have to worry about your knight being kicked away. For example **1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 c5 5.e3 Nc6** and Black is doing fine)
> 4 votes

# Answer
The Benoni defence 1. d4 Nf6 2. c4 c5, which normally continues 3. d5, seems to fit. You then have the choice between continuing more solidly with 3... e5 or 3... e6 and playing the Benko gambit 3... b5.
> 2 votes

---
Tags: opening, 1.d4, queens-gambit-declined
---


title: Who was Bobby Fischer's father?

text:
# Question
Title: Who was Bobby Fischer's father?
This interesting YouTube video asks the question: "Why Did the World’s Best Chess Player Go Insane?" without really answering its own question. It also makes the suggestion, again unsupported by any references, that Fischer's real father was Hungarian mathematician, Paul Nemenyi.

So, who was Fischer's real father? Is there any supporting evidence for the case for it being Paul Nemenyi?

# Answer
The answer is that we don't know for certain. Short of exhuming the bodies of Nemenyi and Fischer\*, taking DNA samples from each, and testing those samples, it seems likely we will never know for certain who Bobby Fischer's biological father was. Even then, we may not have 100% certainty.\**

Regina Fischer's (Bobby's mother) marriage to Hans-Gerhardt Fischer didn't last all that long. Personal issues may have played a part, but Regina's Jewish heritage led her to flee Moscow (where she and Hans-Gerhardt were living) for Paris. Nonetheless, Joan Fischer (Bobby's sister or, apparently more correctly, half sister) is believed to be a result of the marriage. Joan went with Regina to Paris (and later the U.S.) However, it is believed that Regina and Hans-Gerhardt had no in person contact with one another around the timeframe in which Bobby was conceived.

There is circumstantial evidence supporting Paul Nemenyi as Bobby's biological father. It is known that Regina and Paul had an affair in the timeframe around which Bobby would have been conceived. Also, Nemenyi paid money to Regina until his (Nemenyi's) death, which has been said to be support for Bobby. Nemenyi was also observed to have taken an interest in Bobby. Unfortunately, Nemenyi died in 1952, shortly before Bobby turned 9.

While I'd previously read or heard most of the things about Fischer, et al. that I stated above, I relied on the Wikipedia article about him to refresh my memory as I was writing this answer. The sources cited there may provide more information if you want it.

* A DNA sample for Fischer may already exist, as his body was exhumed to help settle his estate. A woman claimed that her daughter was Fischer's child and thus entitled to inherit some of his money. (The resulting DNA test showed that to be false.)

\** I'm not a biologist, let alone DNA specialist, but I do know that DNA can deteriorate over time, so at some point the testing would become inconclusive or even impossible.
> 6 votes

# Answer
I found this interesting Chess.com article which goes into the question in more depth. It gives short biographies of Paul Nemenyi, Regina Wender Fischer and Hans-Gerhardt Fischer along with some details for Joan Fischer, Bobby's older sister, and Peter Nemenyi, his likely half-brother.

Here is how the article describes how Nemenyi and Regina Fischer met:

> In 1942, Dr. Paul Nemenyi, age 47, met Regina Wender Fischer (1913-1997), age 29, in Denver, according to FBI files. Regina was taking classes at the University of Denver while working at a company that made chicken incubators. She was a mother of a 5-year-old girl, Joan Fischer. Her husband, Hans-Gerhardt Fischer, was in Santiago, Chile. He was barred by immigration authorities from entering the United States.
> ...
> In the summer of 1942, Dr. Paul Nemenyi and Regina Fischer were romantically linked, probably had an affair, and he may have fathered Bobby Fischer.

and Regina and Hans-Gerhardt Fischer's early life together:

> Hans and Regina moved to Moscow in 1933 and were married in Moscow on November 4, 1933. She was 20, he was 25. He was a biophysicist working at the Moscow Brain Institute. She was studying medicine at the First Moscow Medical Institute and he was studying biophysics.
>
> Their first born child, Joan Fischer, was born in Moscow in 1937. She died in 1998.
>
> On July 29, 1938, Regina went to renew her passport at the American embassy. She told a staff member that she had separated from her husband. At about this time, Hans-Gerhardt had left or was sent to operated on the Republican side in the Spanish civil war to fight the Fascists.
>
> In late 1938, Regina and Joan departed for France and met up with Hans-Gerhardt in Paris. It's possible they also went to Austria.
>
> On January 23, 1939, Regina Fischer left France and headed to the United States with her daughter, Joan. ... She caught one of the last ships leaving France for America. It is not clear if Hans-Gerhardt was on this ship (he did not have a U.S. passport, but had a Spanish passport). The FBI does say that Hans-Gerhardt Fischer never entered the United States from any ship (was he a suspected Soviet spy?).
>
> The FBI file says that Hans Gerhardt Fischer lived for a time in Port San Antonio and Santiago, Chile where he sold and installed fluorescent lights and worked as a photographer. He landed in Chile on January 4, 1940.

It goes on:

> Regina later divorced Hans-Gerhardt on September 14, 1945 on the grounds of willful neglect to provide for her and her two children. At the time of divorce, Regina was living in Moscow, Idaho. He never lived with her in the United States. He remained a lifelong German citizen.

So, unless she visited her husband in Chile in summer 1942 it is impossible for him to be the father.

Meanwhile:

> Dr. Nemenyi took a deep interest in Bobby Fischer and even paid child support to Regina. At one time, in 1947, when Bobby was 3, he complained to a social worker about the way Regina was raising Bobby. He told the caseworker that Regina was mentally upset and Bobby was an upset child.
>
> ...
> In 1949, Dr. Paul Nemenyi went to a social worker again, complaining that **his son** was not being brought up in desirable circumstances, due to the instability of Regina.

So, Nemenyi acts like Bobby's father. Then:

> Dr. Paul Nemenyi died of a heart attack on March 1, 1952, at the age of 56. He had just stopped at a dance at the International Student House in Washington, DC. There, he dropped dead of a heart attack. He was living in Washington, DC, and working at the U.S. Naval Research Lab. He was survived by his son, Peter , a civil-rights activist. Peter wrote that his father, Paul, was the father of Bobby Fischer.
>
> At the time of his death, Paul was paying for 8-year-old Bobby’s education and sending $20 a week to Regina.

Then the question of what to tell the young Bobby Fischer?

> Regina did not want to tell Bobby of Paul Nemenyi’s death and was hoping that Peter Nemenyi would do it. He was not comfortable with that, so he consulted a family doctor for advice. He wrote to his family doctor, “**I take it you know that Paul was Bobby Fischer’s father**. The matter is further complicated by the false pretenses about Bobby’s identity and the parents’ difference of opinion over the question.” Peter felt he was not qualified to tell Bobby about Paul’s death since Peter had met Bobby only a few times.

The full article is a fascinating read and lays out strong circumstantial evidence that Nemenyi was Bobby's biological father.
> 3 votes

---
Tags: history, fischer
---


# Question
Title: Why is Bobby Fischer's argument against adjournment an argument for increment?
Bobby Fischer, as quoted by Jim Ratliff in a question about increment says:

> The result of adjournments is often a skewing of a particular player's chess-playing ability since the success or failure of a player upon resumption of an adjourned game often depends on the amount of time spent analyzing the game during the adjournment as well as the quantity and quality of help that player had in analyzing the game during the adjournment.… Thus, the play of the game upon resumption of the adjournment does not necessarily reflect the ability of a particular player, but rather it may be more a reflection of the ability of his team of analysts, books and computers. There are many people, including the present inventor, who wish to eliminate adjournments for exactly this reason. A chess game should be an accurate reflection of the ability of a particular player and not a reflection of the strength and ability of his team of analysts, books and computers.

It's a good argument against adjournment, but what's the relevance to increments?

# Answer
The purpose of both increments and adjournments is to relieve some time pressure off of the players. Therefore, the relevance to increments is that increments, or additional time added to the clock after each move, can serve as a substitute for adjournment. It does so by adding a certain amount of time to the clock of each player after every move. This way, the game can continue without interruption, and players have less incentive to use outside resources during the game. It also is completed in one sitting, eliminating the need for a break (adjournment). Fischer was a strong advocate for increments.
> 5 votes

# Answer
"as well as the quantity and quality of help that player had in analyzing the game during the adjournment..." was clearly an issue when he was playing an opponent from USSR.

In any tournament in his prime years there were always many USSR top GMs that could help each other in various ways. Sometimes players could even go to sleep, leave the others do the analysis work, wake-up fresh, study the analysis, and go to the borad to play against an opponent that might have spent the night on the board.

Today with computers adjournment has lost any mening.

Today teams are also different: e.g. Calsen against Nepo had Dubov, a russian as Nepo, in his team.
> 2 votes

---
Tags: history, time-control, increment, adjournment
---


# Question
Title: Longest sequence of moves where White's number of available moves does not change
There are challenges for the longest sequence of moves in which white's available moves increase or decrease. This challenge is for the longest sequence of moves (from the opening position) in which white's available moves stays at 20, without repeating any moves\* or positions. (The fact that a given move can't be played for the purpose of the challenge doesn't prevent it being scored as an "available move").

For instance, after 1. b4 b5, white still has 20 moves available. The pawn has lost two moves, while the dark-squared bishop has gained two moves.

`*` "repeating a move" means moving the same exact piece from the same square to the same target square, and whether it is a capture: "the knight that started at b1 moving from c3 to e4, not capturing". Other considerations like check do not stop it being the same move. (The rule is to avoid situations where a number of interchangeable moves are played semi-repetitively without changing the board meaningfully).

# Answer
Hundreds of moves...

We can shuffle pieces for very long, the main constraint being not to play twice the same move (per OP's definition). Here is an example line with 25 moves, that can easily be prolongated (I may do it when I get some time...):

```
[Title ""]
[fen ""]
[Startply ""]

1. g4 g5 2. f3 h5 3. c4 h4 4. a3 d5 5. Ra2 Qd6 6. b3 Nf6 7. Bh3 Bf5 8. Kf1 Qb6 9. Qe1 Bg6 10. Rc2 Bg7 11. Rc3 Qa6 12. Re3 e5 13. Qf2 Nc6 14. Bg2 O-O-O 15. Qe1 Nd4 16. Kf2 Nc2 17. a4 d4 18. Na3 Kb8 19. d3 Nb4 20. a5 Qc6 21. a6 h3 22. Kg3 Rd7 23.c5 Nfd5 24. Nc2 Nc3 25.Bd2 Re8

```
> 3 votes

---
Tags: problems, records, mathematics
---


title: What does FIDE rating 1800 entail?

text:
# Question
Title: What does FIDE rating 1800 entail?
I have a classical rating of around 2000 on Lichess. I’m aware that FIDE Classical time control is much longer than Lichess classical, so I just made it as some kind of reference point.

I’m mainly working on Soviet Chess Primer, Yusupov 1, and a tactics/endgames book that I carry with me.

There seem to be three main concepts that people advise intermediate players to focus on: Tactics, calculation/endgames, and positional concepts. Many say that the first two would produce most value for time put into.

So I think my question would be that what kinds or levels of tactics and calculation skills would someone of FIDE rating 1800 have? What differentiates someone of FIDE rating 2000 from 1800?

# Answer
As I have said before, learning chess is not like a factory. There is no checklist to complete to get a FIDE 1800 rating. However, a lichess.com rating of around 2000 generally does mean that you are in the 1800 range. But you are correct that tactics, calculation, endgames, and positional understanding are important. However they are also all related. Treating them as separate and focusing ont hem only separetly is not useful. What I would suggest is focusing on what you do wrong in games that you lose, which is true of any rating. Most of chess is learning from your mistakes.
> 1 votes

---
Tags: learning, fide, rating, tournament, tactics
---


# Question
Title: Why didn't Laurent Fressinet-Alexandra Kosteniuk (2007) end in a draw?
Game is available here. The last 116 moves of that game was R+B vs. R, which is a theoretical draw that is hard for a human to defend. Fressinet eventually faltered and resigned when he was about to be mated.

Wikipedia gives this description of the game:

> The last 116 moves were a rook and bishop versus rook ending, as in Nikolić – Arsović. Fressinet could have claimed a draw under the fifty-move rule, but did not do so since neither player was keeping count, it being a rapid chess game. Earlier in the tournament, Korchnoi had successfully invoked the rule to claim a draw against Fressinet; the arbiters overruled Fressinet's argument that Korchnoi could not do so without keeping score. Fressinet, apparently wanting to be consistent, did not try to claim a draw against Kosteniuk in the same situation.

However: given that 116 moves is well over the 75 moves required for an arbiter to intervene, why didn't this game end in a draw?

# Answer
> 8 votes
The 75 move rule was introduced in the 2014 version of the Laws of Chess. The previous version of the rules has no mention of it. Since this game is from 2007, it obviously wouldn't have used a 2014 version of the rules.

# Answer
> 1 votes
As the other poster already noted, the 75 moves rule did not exist at that time. So the 50 moves rule applied. From Wikipedia:

> A game is not automatically declared a draw under the fifty-move rule; the draw must be claimed by the player whose turn it is to move. Therefore, a game can continue beyond a point where a draw could be claimed under the rule.

As Fressinet did not claim, the referee did not interfere.

---

However, even if the 75 move rule existed, it would have been not totally clear. The current FIDE rules (9.6.2) say that "the game is drawn" in this case, but do not state what the referee has to do.

The editor of this Wikipedia lemma claims "the draw is mandatorily applied by the arbiter".

But I do not see this in the FIDE rules. They denote the state of the game, but not the resulting action.

An arbiter who wants to please his observers may not want to interfere in the running game. Or the result of the game may decide who wins the tournament. Again, the arbiter may be interested to let the game run a bit.

So, if the arbiter does not interfere, and the players continue, and one player wins, then the game first was drawn according to the rules, and then it was won according to the rules. This is a paradox, but so far the FIDE rules do not declare this to be illegal.

---

More Information about the difference between 50 and 75 move rules in this related question.

---
Tags: endgame, history, draw, 75-move-rule
---


title: Variant where White cannot lose?

text:
# Question
Title: Variant where White cannot lose?
I was pondering an asymmetrical variant where White's king is just a regular piece that moves like a normal king, but can be captured without consequence (and hence check for White does not exist). The game would consist of Black attempting to avoid being checkmated for X moves. (X might be 30?)

Is there any such known variant?

# Answer
> 2 votes
A similar variant absouletly exists and is called Mate in X chess. Generally it is used as a training tool or for when you have 2 opponents with a vast disparity in rating. For example, the goal may be to checkmate black in 20 moves, otherwise you lose. However white can lose the traditional way, but that is generally rare.

---
Tags: chess-variants, winning, solving
---


# Question
Title: Why is increment more popular than delay?
Increment is FIDE's default for their tournaments, although their rules permit delay as well. Most internet chess servers also use increment exclusively.

As I understand it, delay is used by the USCF (for historic reasons?), and, for some reason, by the 2017 Grand Chess Tour.

Why is increment preferred over delay by pretty much everyone but the USCF?

# Answer
Very simple. Move quickly (faster than the increment) and you end up with more time. Over the course of a dozen or so quickly made moves you can build up enough time to allow for another serious think if required.

With delay you can never get more time. Once in zeitnot you are permanently in zeitnot.
> 8 votes

# Answer
**Virtually "Delay" can be considered as a special case of "Increment"**. Both gain time in their own way, but "Delay" is limited to first few seconds, while "Increment" always guarantees the time gain.

e.g. 10 sec "Delay" will allow the player to gain time only if the player makes a move within their *first 10 sec*. Kind of enforces a quick play. After certain number of moves, it typically gets difficult to play quickly especially in a lesser time controls. This may cause unexpected blunder or weaker play eventually.

In case of "Increment" the time always gets added (unless the player has timed out). This allows the player to think their moves properly within their total time frame. Usually such moves generates a better game from both the sides.

Hence majority of the tournament opt for "Increment" over "Delay".
> 1 votes

---
Tags: time-control
---


# Question
Title: Why is f3 not as strong in some sicillian dragon?
In many setups where black plays g6 Bg7 I enjoy playing f3 Be3 Qd2 and looking to either play Bh6 or storm my g&h pawns. I like f3 because I don't have to worry about any knight attacks on my bishop (I realize I don't always have to worry about the knight attack but often I find myself spending too much time and not knowing what to do if black plays that way). Here is the line where I play f3 and I believe it is solid:

```
[fen ""]
[Startply "13"]

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 g6 6. f3 Bg7 7. Be3

```

**My question is why is f3 not as strong when Nc6 is played rather than d6.**

Is there a clear conceptual reason why f3 is not as strong (compared to the line above) in the following line:

```
[fen ""]
[Startply "15"]

1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 g6 5. Be3 Bg7 6. Nc3 Nf6 7. f3?

```

I usually play both lines because I understand the ideas. Another questions, do you have any advice on where I can improve in this Nc6 line? If you suggest something else please explain the idea. I realize there is probably nothing horribly wrong with f3 against Nc6 but it doesn't appear to be as consistent as against d6, but I can't see a reason why. It looks like the main moves are 7. Bc4, 7. Be2, 7. Nxc6, 7. Nb3.

# Answer
> 7 votes
This question is about the Accelerated Dragon, where Black hasn't yet committed to playing d6. The entire point of the Accelerated Dragon is to dodge the Yugoslav attack lines you want to go into, using the following resources.

The first point is that, since black hasn't yet played d6, they are threatening to play d5 in one go. This counters your planned attack on the flank with your g and h pawns by opening up the centre, one move up compared to if they tried that in normal Dragon lines. There's one reasonable move to prevent this: Bc4.

In your line, this would occur after 7.f3? 0-0 8.Bc4, though a lot of other players encounter this by first playing Bc4, and then asking why 7.Bc4 0-0 8.f3? is bad. And the reason why is because it walks into the following trap.

```
[fen ""]
[Startply "16"]

1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 g6 5. Be3 Bg7 6. Nc3 Nf6 7. Bc4 O-O
8. f3? Qb6! 9. Qd2 Nxe4

```

8.Qb6 works because the knight is pinned to the undefended bishop on e3, and it threatens both the b-pawn and the discovered attack Nxe4. (The best move at move 8 for white is a retreat of the bishop back to b3, covering the b pawn.)

Playing f3 on move 7, you leave yourself with a choice between two bad options after black castles. Either you walk into this trap. Or you forgo Bc4, letting black play d5 and get everything they want out of this opening.

---
Tags: opening, sicilian-dragon, accelerated-dragon
---


# Question
Title: What is the origin of the Caro-Kann Two Knights Variation?
It starts with **1. e4 c6 2. Nc3 d5 3. Nf3**. I checked the 1984 edition of *The Oxford Companion to Chess*, and all it said was that it was popular in the 1950s. Any information would be valuable to me.

```
[Title "Caro-kann - Two Knights variation"]
[FEN ""]
[StartPly "5"]

1. e4 c6 2. Nc3 d5 3. Nf3

```

# Answer
It is unclear when it originated, but the normal variation started in 1886. The first recorded game I could find using it is in 1908.

Source:Wikipedia
> 3 votes

# Answer
This is the first game in 1908 I found when searched in the Mega Database. After that there were games in 1922, 1923 played by Bogoljubow, Tarrasch and Capablanca

```
[FEN ""]
[Event "Lasker Emanuel tour sim"]
[Site "Netherlands"]
[Date "1908.??.??"]
[Round "?"]
[White "Lasker, Emanuel"]
[Black "Radsheer"]
[Result "1-0"]
[ECO "B11"]
[PlyCount "21"]
[EventDate "1908.??.??"]
[EventType "simul"]
[EventRounds "1"]
[EventCountry "NED"]
[SourceTitle "EXT 2001"]
[Source "ChessBase"]
[SourceDate "2000.11.22"]

1. e4 c6 2. Nc3 d5 3. Nf3 dxe4 4. Nxe4 Bf5 5. Ng3 Bg6 6. h4 h6 7. Ne5 Bh7 8.
Qh5 g6 9. Bc4 e6 10. Qe2 Bg7 11. Nxf7 1-0

```
> 0 votes

---
Tags: opening, history, caro-kann
---


title: Doubt on scotch opening

text:
# Question
Title: Doubt on scotch opening
Why does f6 gives white this big advantage? Furthermore, would it be more appropriate for white to capture the black pawn on e5, effectively giving away a central pawn, or to develop the light squared bishop on c4?

# Answer
The reason why ...f6 is a bad move in the given position has to do with king safety. After Black plays ...f6 it is going to be extremely difficult for Black to defend the a2-g8 diagonal in the long run, and if white just places their light-squared bishop on c4 Black will not be able to get their king to safety by castling short.

But this is just scratching the surface of the long-term problems with ...f6. There are common tactical motifs against Black's king that become possible after Black plays ...f6 as well that one should be familiar with. Take the following lines after 3...f6, which in no way are meant to represent optimal play, but which illustrate some important points to keep in mind:

* 4. dxe5, fxe5 5. Bc4 Be7?? 6. Qd5!, and there is no good way to defend against White's mate threat on f7. Of course, it is not necessary to play the blunder 5... Be7?? here, but the fact is that f7 is very hard to defend when there is no pawn occupying the square, and these kinds of tactics are very hard to deal with for Black in the long run.
* 4. dxe5 Nxe5? 5.Nxe5 fxe5 6. Qh5+ g6? 7. Qxe5+, and white wins the rook on h8. Once again, Black is not forced to go into this line either, but the weakening of the h5-e8 diagonal is a big problem for Black in these situations and gives White many nasty tactical possibilities connected with moving their knight from f3.
* 4. dxe5 fxe5, 5. Bc4 Nf6 6. Ng5 d5 7. exd5 Nxd5 8. Qf3, and Black is once again struggling to defend the weak f7 square. These kinds of motifs are usually not as dangerous for black in normal lines as they are here, but in this case Black has kind of "lost" an important tempo by playing an early ...f6, which has given white more time than usual to set up their attack.

So, in summary, ...f6 is bad here because:

1. it weakens important squares around Black's king, giving White a clear target for attack, while making it harder for Black's king to find a safe haven,
2. it wastes time, which makes it easier for White to set up a dangerous initiative against Black's king.

The above scenario is quite typical, and an early ...f6 is therefore often bad in many different openings. One of the few openings where an early ...f6 is sometimes a good idea is the French defense, and that is because in that particular opening none of the points I made in this post necessarily apply due to the special pawn structure in that case.
> 7 votes

# Answer
First of all, that is not the best move. Stockfish at depth 30 on a 16 CPU core with the latest offical realease says that bb5 is best. This is actually the Ruy Lopez opening, who probably released that f6 was a pretty dumb move as well. The Ruy Lopez attacks a knight which can be an annoyance if black plans to use that knight. It also gets out a bishop. F4 would also be a reasonable move in that position, also not the best for reasons that BB5 is actually helpful (described above). I actually tried playing this Stockfish vs Stockfish (same config as earlier) and white never lost the advantage the entire game and went on to win it, meaning that this opening is quite good. Black won when I tried F3.
> -1 votes

---
Tags: opening, scotch-game
---


title: What is a logical move?

text:
# Question
Title: What is a logical move?
I'm not sure as to what constitutes as a logical move. Sometimes I hear that chess is a discussion using statements, arguments, questions and answers.

Can someone explain to me what a logical move would be given this context? A nice, practical example would also be of great help to me.

# Answer
A move which is obviously not bad to play. It's a fuzzy word to describe and evaluate a move, so it's hard to explain (it's strongly opinion based). Maybe we can put a logical move in the middle of this list:

```
!!  an excellent move
!   a particularly good—and usually surprising—move
!?  an interesting move that may not be best
>>> Logical move is here and contains above <<<
?!  a dubious move – one which may turn out to be bad
?   a bad move
??  a blunder

```

Although, ideally speaking, the logical move is *the best move*, but It may not the case in your question.

Consider this position between Anand.V vs. Carlsen.M - the World Championship match. For an average rated player there're many *logical* moves such as `1.R4c3`, `1.Rd1` and even `1.Kg2`. By playing those moves his coach will not criticize him and he will say OK you made a logical move. But..

```
r3b3/1kp5/1pn1P1p1/pN6/2R3Pr/1P6/5N2/2R3K1 w - - 1 35

```

In the world championship between two giants, the only logical move is `1.Ne4!` which is played also. (Even my chess engine find it hard)

A hint from Karpov, *exact calculation in a game is much preferred rather than general guidelines*. Guidelines do not find the best or logical move, they will be used to find logical candidate moves and then a exact move calculation will find the best move from the list. See the example again, a general guideline says try to protect your pieces but a comprehensive calculation says another thing. Ne4!. Which one is logical for GMs ?!
> 2 votes

# Answer
I actually disagree with the accepted answer.

To say that a move is logical says nothing at all about whether it is good or bad. If a move is logical, it only means that it makes a lot of sense from a chess perspective. A logical move is the "obvious" move to make in the position.

To elaborate - the move might be logical because it fulfills a strategic purpose or is the pawn break that makes the most sense. Determining whether or not a move is logical involves no calculation.

As an incredibly contrived example:
In this position, the logical move is `1. f4` because it's the only pawn break for white that makes sense. However, this move happens to lose the queen because the pawn is pinned.

```
[FEN "r4rk1/2n2ppp/3p4/q1pPp2b/1pP1P3/pP1N1PP1/P5BP/3QRRK1 w - - 0 0"]

```

That's a vastly oversimplified example, but hopefully it illustrates the general idea: the logical move requires no calculation and depends only on general principles.
> 2 votes

# Answer
I believe I have a precise definition: a logical move is the one that comply with the principles of classic chess strategy.

In the context of "chess being a discussion", the move would be a reply to another one, both respecting the main principles. The "logic" is the whole set of principles. The arguments, statements, questions an answers derive from the analysis of whether the move respected some principles or not, and whether it would be disrespecting a principle to create advantages in the future.

Suppose my opponent makes a move that respects the principle of "control the center", and I respond with a move that sacrifices a piece "to create a weakness" (if this weakness was indeed created or not, we don't know yet). My opponent's move would be considered "logical", and my move could be considered a blunder or a "surprising" move, depending on how the game would progress from that. In this example, my move was not "logical" from the perspective of the principles of classic chess.
> 0 votes

---
Tags: learning, strategy, terminology
---


# Question
Title: How much does adding an opening book to a relatively weak chess program affect its strength?
Jonathan Schaeffer in One Jump Ahead (via the Chess Programming Wiki):

> To solve the opening problems of his chess machine, Belle, Ken Thompson typed in opening lines from the Encyclopedia of Chess Openings (in five thick volumes). Religiously, he dedicated one hour a day for almost three years (!) to the tedious pursuit of entering lines of play from the books and having his Belle computer verify them. The result was an opening library of roughly three-hundred thousand moves. The results were immediate and obvious: Belle became a much stronger chess program, and Ken probably aged prematurely.

I read somewhere else that Belle eventually reached the equivalent of 2250 Elo (I assume that was in terms of USCF ratings), but I couldn't find any information about its rating gain due to the opening book.

So here's a more general question. Suppose we take a relatively weak chess engine that doesn't use an opening book and that has a known rating from a pool that includes humans (e.g. Lichess or chess.com). How much stronger would it be if we added an extensive opening book to it?

Let's assume the engine's original rating is anything between the equivalent of 1000 to 2000 FIDE. This is an arbitrary range. The idea is that if the engine is too weak, then the opening book would be just covering for the lack of any search/evaluation, and if it's too strong then the opening book would get less necessary. Of course I expect the answer to be different depending on the strength of the original engine.

# Answer
> 3 votes
I have written a relatively weak chess engine (source code here). After playing it manually against "Play Computer" at chess.com I estimate its strength at 1500 to 1700 Elo points.

I added a learning opening book to it (around 150 openings entered by hand and currently around 18000 moves learned). It now sometimes wins against "Play Computer" with 2300 Elo points.

Without opening book, its chances are low to reach a good position in the middle game. With opening book it reaches neutral to good position quite frequently. From there it has a chance to win because it plays stronger if there are less pieces on the board.

I think that confirms the comment from Oscar Smith above.

# Answer
> 1 votes
Stockfish gains about 50 elo from the Cerebellum opening book ("Brainfish" is just Stockfish equipped with Cerebellum).

I don't know if the effect of opening books varies depending on engine strength, however.

---
Tags: opening, computer-chess
---