# Question
Title: Why do GMs participate in an "GM norm invitational" tournament?
I'm following the current GM/IM norm invitational tournament recaps thanks to GothamChess YouTube channel (IM Levy Rozman is playing).

Such an event (for GM norms) requires at least 3 (1/3) GMs to participate in the tournament.

IMs obviously participate because they're hunting for a GM norm.

But why do GMs participate? (are they paid? Chess ethics? is it mandatory?)

And what is their attitude (generally) towards the IMs? (for instance, offer a draw "easily" if the candidate is good enough (but not strong enough to win), or are they really playing their best to "filter out" the IM candidates?)

# Answer
Grandmasters are financially incentivized to play in GM-norm invitational tournaments. The incentive can take different forms depending on the organisers' choice.

Most often, GM are invited (travel, hotel and meals paid, with no fee asked for playing) and they compete for the money prizes in the tournament (usually the top 3 out of 10 players get money prizes). So at the very very least that week doesn't cost them anything, and they may come home with a few thousands euros or dollars.

In this version they tend to play their best to maximize their money prize.

In some other events they are actually paid to play, but money prizes are low. In that case their incitations to do their most are mostly rating points, fighting spirit and love of the game. Many grandmasters are great fighters even in those circumstances, but some tournaments have the reputation of being "good places" to achieve IM- or GM- norms, because the grandmasters there are less motivated to do their best...

About playing style and draw offers, each player has their own habits. Some tournaments don't allow draw offers at all. Note that achieving a norm usually requires 6/9 or 6.5/9 (+3 or +4), so the "perfect plan" of three draws against GM and 5/6 against fellow candidates is not easily achieved. As often as not, a draw won't be enough and you will need a win against a GM, so you might prefer to face a "fighter" who tries to beat you and gives you chances than a non-ambitious, super-solid opponent aiming for a draw.
> 14 votes

# Answer
converting comment to answer:

I figure because they are more likely to win against non-GMs as opposed to other GMs. so it's a win-win: the non-GMs have a chance to prove themselves to get their norms, and the GMs have a good chance to win.
> 1 votes

---
Tags: tournament, grandmaster, international-master, norm
---


# Question
Title: Why did I improve quickly after stopping resignation?
About a week ago, I decided to never resign unless I am in a completely losing endgame and to always play to checkmate unless it would be a complete waste of time(say in a queen vs lone king endgame). After doing that, my rating, accuracy, and win/loss ratio went up very quickly, and I made more progress in a few days than I did in 2 months beforehand. Why did this happen?

# Answer
> 5 votes
You didn't get better. You just stopped losing as much - by definition, instead of losing 100% of those games you started losing less than that - and your rating went up.

Ratings measure performance, not ability.

# Answer
> 4 votes
There can't be a definite answer to your question without sharing some examples of your games, but it seems obvious that your rating and winrate will be lower if you resign positions where there's still hope.

# Answer
> 1 votes
As others have said, more info on your situation would help but here is my stab:

* Rating & win/loss ratio: especially on lower levels, many players struggle to convert winning positions, so if you play on instead of resigning, your win/loss ratio and rating would naturally increase.
* Accuracy: Accuracy usually measures how often you find the best computer move. It is often easier to find the best move in a losing position because your opponents threats would typically reduce the number of candidate moves to a handful miserable defences. I've had totally losing games on chess.com with an accuracy of 98% because after the blunder, all my subsequent moves were easy (and losing).

My guess is that you are not necessarily playing better but just "gaming" the stats better.

Of course, it is entirely possible that simply adapting your playing style has motivated you to take the games more seriously, reducing mistakes and genuinely improving your play. Congrats in that case.

---
Tags: psychology, resigning
---


# Question
Title: Straightforward refutation of the Stafford gambit
I recently found the the following line that completely neutralizes the Stafford gambit, and lets white keep the pawn with a healthier structure and a calm game ahead with plenty of winning chances.

```
[FEN ""]
1. e4 e5 2. Nf3 Nf6 3. Nxe5 Nc6 4. Nxc6 dxc6 {The Stafford Gambit.} 5. e5!! {Now black has a couple of options} Nd5 {Is best, but rarely played.} (5... Ne4?! 6. d4 Qh4 7. Be3 {With the simple idea of Ne2, exchanging knights, and keeping the healthy pawn, the superior structure, and a calm game with winning chances.}) (5... Ng4?! 6. d4 Be6 7. h3 Nh6 8. Bxh6 gxh6 {With the simple idea of Nc3, Qd2, 0-0-0, and if black ever pushes c5 white replies with d5.})  6. d4 Bf5 7. c3 Qd7 8. Nd2 O-O-O 9. Nf3 {With the idea to finish development and play with O-O-O, or Be3 and O-O.}

```

I was surprised by the very little theory required to play these lines, as well as the tameness of black's position. Since the Stafford gambit has this reputation of a heavily theoretical opening plagued with traps, and this move order seems to make black's plan innocuous, am I missing something? Is my analysis flawed?

# Answer
This youtube video on the Stafford gambit discusses possibilities after `5. e5` in some detail, and suggests your `5... Ne4` line, continuing with `7... f6`. Your suggestion of `8. Nd2` certainly looks better than the next move considered there.

Obviously if the main strength of an opening is that it produces traps then when your opponent knows how to avoid the traps you should expect them to reach a strong position.
> 3 votes

---
Tags: opening, gambits, opening-traps
---


# Question
Title: There is neither checkmate nor stalemate, so why did black win?
I'm programming chess in python for my cs class and I'm doing some testing using chess.com. However, I'm confused as to why this game (and several others) seem to prematurely come to an end?

AFAIK the end-conditions to chess are

* checkmate, where the king theoretically will be taken next move
* stalemate, where there are no valid moves
* running out of time.

This game is only 19 moves long and ended with black winning. Can anyone tell me why?

# Answer
Most probably White resigned.

This is a common decision to be made in a desperate position such as this one, where there is no doubt Black will be able to win anyway and the 10 or 20 more moves technically needed before checkmate are merely a waste of time.

My hypothesis can only be confirmed if you give us some informations about where the found this game and the circumstances in which it was played.
> 18 votes

---
Tags: rules, winning
---


title: Semi-Slav name origin

text:
# Question
Title: Semi-Slav name origin
The name Semi-Slav suggests that somehow it's half of a Slav. How did this name come about? Or what does it mean? The two openings seem completely different to me due to the fate of the c8 bishop.

# Answer
> 16 votes
It simply because

> With Black advancing pawns to both e6 and c6, the opening resembles a mixture of the Orthodox Queen's Gambit Declined (QGD) and the Slav Defense.

(from wikipedia)

If you consider that there are two components to the mainline Slav - protect the d5 pawn with c6 and then develop the light-squared bishop to f5/g4 - then the semi-Slav only shares one of these two features.

---
Tags: opening, slav-defense, semi-slav
---


# Question
Title: Are there mobile chess tutoring/training apps for Android or iPhone?
I'm looking for a Chess tutoring/teaching app that I can dip in and out of on my phone. At the moment I use Shredder Chess to practice when on the move (which basically involves repeating the puzzles over and over) but I was looking for some sort of app which has structured lessons on openings, defenses etc. and explains the positions in depth like Chess Mentor does.

Does anyone know if this type of app exists?

# Answer
Here are my Chess apps for Android:

**iChess** — lots of chess tactics to solve, all offline. You can also load your own PGN or purchase recent tactics based on openings, or from recent games.

**Chess Book Study** — a very innovative app that shows a board and an eBook in the same screen. It makes it easy to study chess books. You can even dictate and the moves are made on the board.

**Analyze This** — analyze a position with two engines, simultaneously!
> 18 votes

# Answer
Try the Chess.com app.
It allows you to play against real people and against the computer. It has puzzles based on tactics to solve & videos by experts.

Android Version (requires Android OS 1.5 or later)

iPhone Version (requires iOS 3.0 or later)
> 8 votes

# Answer
The one that I could not recommend more for iOS is Chessimo.

This has great ability to train you for tactics, strategy and endgame. I teach a few people how to play chess well and this method seems to be very helpful. If you want to get to a decent level fast- focus on tactics, then strategy, then endgame and at the end opening.

This program makes it easy and fun!
> 8 votes

# Answer
Try this app, Tactics Trainer. It has helped me a lot and has a lot of puzzles, but I dunno if it has an iOS version.

I play at chess.com, which has an app, too, for android and iOs. I play with real people and it has 3 free puzzles per day.

Both apps have some graphics about your games or puzzles, and your ELO rating.

Edit:

By the way, chessimo is really good but I don't think it has a free version, or it is just a demo; to get the full version you have to pay, but it is really good, it was the first Tactics trainer app I used.
> 6 votes

# Answer
I recommend Chess King Learn for chess education. The apps are developed by our team and can help chess lovers of any level and age to study chess.

The app is presented for Android, iOS and macOS platforms. Also there is a web version. You can study on any platform you want.

You may choose your course in the apps linked above, they include 90+ chess courses. Each course has a free part, so there are thousands of free puzzles in total. If you'll fall in love with one of the courses, you may purchase the full version ;).

Beside the main app there are more than 60 single applications where you can focus on a specific course. Here is the list of top rated ones:

Full apps list is here.
> 6 votes

# Answer
For Android you can also try Chesster. It lets you import an ebook with chess moves, and makes it interactive, showing the movements in a chessboard.
> 4 votes

# Answer
You can try Christal Kernel's Chess Wizard for iOS.

It trains you while playing. It gives a feeling that there is a real coach around. Throws situation based puzzle on the board. Makes the game interesting for the learners.

Detailed information on their website.
> 4 votes

# Answer
For Android check out Chess Endgames. It's free and has a number of different positions to work through.
> 4 votes

# Answer
I know there are already a lot of answers here, but one that isn't mentioned is the Chess24 app. I really like the tactics trainer from the app and find that for the money it is a better value than others I've seen. (Should still be $20 for 1yr of unlimited tactics.) There are also great apps for iOS at least that allow you to read chess books and follow along with a chessboard like Forward Chess or e+books Chess. I have found this to be incredibly helpful in studying.
> 4 votes

# Answer
For the several facets of the game, you may use different apps. I include them all on the comments, since I'm not allowed to post them here.

**Tactics:** This very important part of the game can be trained by the already mentioned app "Tactics Trainer". I'm a daily user, and it's excellent.

**Openings:** The best app I can think of in this area is "Chess Repertoire". The app is excellent, with a nice clean design and with more opening positions that you'll need. It even has space for personal annotations and novelties. The sole drawback is that only the first moves are free, and you've to pay for the rest of it.

**Endgame:** I've been recommended "Chess Endings", which is not free, and cannot say much about it. You may try it.

**Casual play:** I strongly suggest the Chess.com app. You have a few additional tactics problems, but the interesting thing is the correspondence and live chess, playing whenever you feel.

**Analysis:** With abysmal difference, the best analysis tool you can possess for a mobile device is "Scid". It is beautiful, the pieces are shown clearly, there's space for the game score and admits an engine. It also allows you to export games to .pgn and many more things. Priceless, but open source and free. Despite it comes with an engine by default, Stockfish, downloadable from here, can be compiled into any Linux device, and it's certainly the best option if you possess an Android.
> 3 votes

# Answer
Try Chess Run

It's a chess-based platform game - not a pure chess game but a platform game featuring the standard chess pieces which are used to cross a burning board filled with enemy pieces. You have the option of highlighting squares that your pieces can move to so it's a good way of learning the moves. It's also fast-paced so will help with speed chess.
> 3 votes

# Answer
https://itunes.apple.com/ca/app/chesstutorapp/id1096289047

ChessTutor - rates your moves as you play through Master games.

PS: This is my app.
> 3 votes

# Answer
Rather than installing an app you can use the mobile interface of the tactics trainer at http://chesstempo.com.
> 2 votes

# Answer
For opening training using GM stats and engine analysis: http://www.chessopeningsapp.com
> 2 votes

# Answer
My own web application works on mobile devices through a browser

https://www.apronus.com/chess/puzzles/

It is a treasury of interactive chess puzzles rather than a step by step course.
> 0 votes

# Answer
(i'm answering 9 years in the future, a huge cheat. lol.)

Besides chesstempo, there's lichess.

You can do tactics on lichess but there are also studies eg this endgame study.
> 0 votes

# Answer
this is my suggestion 1. chess.com 2. Follow chess 3. Chess Book Study 4. Droidfish chess 5. ChessOcr http://newchessbasics.blogspot.com/2015/07/best-5-chess-android-apps.html
> -1 votes

# Answer
My suggestions are ChessAcademy, and Shredder in Android.
> -1 votes

---
Tags: software, training
---


title: What is the point of time increments?

text:
# Question
Title: What is the point of time increments?
I am having difficulty understanding the purpose of increments in time control. What is the point? If it just adds more time to the game, why not simply make the game that much longer? I am aware that I am missing something fundamental here. Apologies for this complete newbie question!

# Answer
> 16 votes
It depends on what you mean by "increments". If you are referring to something like "playing a game in 10m + 4s", then the main reason is preventing that a player with a huge material advantage (v.g. king plus rook versus king) doesn't lose on time. With the increment of 4 seconds after each move is made, the player with the advantage will have no problem winning the position. Without increment, if the advantageous player has something like 1 or 2 seconds on their clock (and provided the other player has plenty of time, or just much more than a couple seconds) they'd probably lose on time -which usually is called "getting (dirty) flagged" in games without increment.

This is a somehow famous example of an online game in which Gata Kamsky was (dirty) flagged in a 3 minutes game without increment, with just one rook and king per side.

# Answer
> 5 votes
There is a big clue in the FIDE Laws of Chess in the section titled "**Guidelines III. Games without increment including Quickplay Finishes**" which deals with games or final parts of games with no increment in rapid and standard where one player is at risk of losing on time unjustified because they have a better or even winning position.

A modified version of this section was originally in the main body of the rules as what was the infamous article 10.2. Then it migrated to the appendices, specifically appendix G. Finally in 2017 in was moved to a new section of "Guidelines". The plan is that in the next iteration of the rules due this year (let's see if Covid delays that process) it will be removed altogether.

What this evolution tells us is that playing without increments, at least for standard and rapid, is deprecated. If you look at the guidelines you get more evidence of this.

> III.4 If the player having the move has less than two minutes left on his clock, he ***may request that an increment extra five seconds be introduced for both players***. This constitutes the offer of a draw. If the offer refused, and the arbiter agrees to the request, the clocks shall then be set with the extra time; the opponent shall be awarded two extra minutes and the game shall continue.
>
> III.5 If Article III.4 does not apply and the player having the move has less than two minutes left on his clock, he may claim a draw before his flag falls. He shall summon the arbiter and may stop the chessclock (see Article 6.12.2). He may claim on the basis that his opponent cannot win by normal means, and/or that his opponent has been making no effort to win by normal means:
>
> III.5.1 If the arbiter agrees that the opponent cannot win by normal means, or that the opponent has been making no effort to win the game by normal means, he shall declare the game drawn. Otherwise he shall postpone his decision or reject the claim.
>
> III.5.2 If the arbiter postpones his decision, the opponent may be awarded two extra minutes and the game shall continue, if possible, in the presence of an arbiter. The arbiter shall declare the final result later in the game or as soon as possible after the flag of either player has fallen. He shall declare the game drawn if he agrees that the opponent of the player whose flag has fallen cannot win by normal means, or that he was not making sufficient attempts to win by normal means.
>
> III.5.3 If the arbiter has rejected the claim, the opponent shall be awarded two extra minutes.
>
> **III.6 The following shall apply when the competition is not supervised by an arbiter**:
>
> III.6.1 A player may claim a draw when he has less than two minutes left on his clock and before his flag falls. This concludes the game. He may claim on the basis:
>
> III.6.1.1 that his opponent cannot win by normal means, and/or
>
> III.6.1.2 that his opponent has been making no effort to win by normal means.
>
> In III.6.1.1 the player must write down the final position and his opponent must verify it.
>
> In III.6.1.2 the player must write down the final position and submit an up-to-date scoresheet. The opponent shall verify both the scoresheet and the final position.
>
> **III.6.2 The claim shall be referred to the designated arbiter**.

The first thing to note is that the very first way of handling this situation is to introduce increments!!

If you read on you see why this is so although it is not explicitly mentioned. That is that the result of the game is decided by the arbiter making a decision and not by the play of the players. This is regarded as being both unjust and unfair to the players and unfair to the arbiter who has to take responsibility for deciding the outcome of the game.

The principle function of the arbiter is spelt out in article 12:

> **Article 12: The role of the Arbiter (see Preface)**
>
> 12.1 **The arbiter shall see that the Laws of Chess are observed**.
>
> 12.2 The arbiter shall:
>
> 12.2.1 **ensure fair play**, ...

It is not the job of the arbiter to decide who wins, loses or draws, yet that is what the Quickplay Finish rules call upon the arbiter to do.

You may be wondering why I have included section 6 and bolded it. Section 6 applies when there is no arbiter present at the tournament. This is not ideal and is not permitted for high level FIDE tournaments but is allowed in things like local leagues which are FIDE rated. What happens here in such a case is that the game stops when the player makes the claim, the position is written down and the scoresheet with the moves and position is sent to the off-site arbiter. They then make a decision. If they reject the claim then the player making the claim loses the game. If there is doubt in the mind of the arbiter then the benefit of the doubt is given to the other player, the player who is supposedly trying to win.

That is why in the next iteration of the rules this is section is likely to be removed and games played without increments will be sudden death as it currently is in blitz.

# Answer
> 4 votes
Because "that much longer" changes with the move count. You can't look at a 15+15 minute time control and say "why not make it an hour?" because scholar's mate exists, so you'd be overestimating, and the 50 move rule exists, so you'd be underestimating.

# Answer
> 2 votes
Increments let you play endgames with time to think. Without them, the end of a game will usually be a time scramble.

# Answer
> 1 votes
It ensures that you'll always have some time left after you move so that you won't lose a game "on time", i.e. as long as you move within the incremental interval. For example, if it were a 10 minute game with 5 second increments, and you got down to a point where you only had several seconds left on your clock, as long as you could continue to move within the 5 seconds for each move, you would never run out of time. Of course, by rushing you might not be making the best moves and could lose that way if your opponent capitalized on any errors you might make. To answer your direct question, it adds time to each move, not just to the entire game, which is a totally different thing. If you just added time to the game, you could still run out when you got to the time limit since you wouldn't be able to move fast enough to avoid that.

# Answer
> 0 votes
I have 2 ways to respond to this post

Way1:

3min + increment 2sec is not exactly equal to 4min20sec + increment 0sec, but 4min20sec is the benchmark to estimate how long a game will take to classify 3min + increment 2sec as blitz/bullet/rapid/hyperbullet/ultrabullet/classical/slow rapid/fast rapid based on that an average game is supposedly 40 moves.

However, a game may not be at most 40 moves. It could reach 60 moves. In particular...

Way2:

...a no increment game of 60 moves may end largely in part of whoever/whomever can move faster and find/avoid checks faster.

My 2nd way to respond to this post is that I think usually people will ask instead why people still don't play with increment after Fischer introduced increments (to chess and chess960...and I guess to go, shogi, xiangqi, etc. Wonder how those games were affected by Fischer's increments). So, I think the question of why people play with increment can be answered with Q&A's about why people play without. Eg this reddit post:

What's the appeal to playing no increment chess? https://www.reddit.com/r/chess/comments/hnj8ot/whats\_the\_appeal\_to\_playing\_no\_increment\_chess/

# Answer
> -1 votes
It was done to make Fischer happy. He thought that if he was in time trouble that he should still have xx seconds to move.

Others of us say that chess is a timed game and if you get into time trouble then you deserve to blunder or see your flag fall.

Increments make the game much longer and for speed chess totally distorts the time control. My friend likes to play 15min game with ten seconds added per move. I say that is like postal chess as I prefer to play at ten minutes dropdead game over after you used that much time.

---
Tags: rules, fide, time-control
---


# Question
Title: Easy variation to learn with White against Semislav with not many lines and avoiding the Slav at the same time if possible
I'm looking for an easy variation to learn against the Semislav. Note that I play d4, c4, Nc3 against many openings. I tried to play the 5.Bg5 line but I felt that it was full of memorization:

```
[FEN ""]
1.d4 d5 2.c4 c6 3.Nc3 Nf6 4.Nf3 e6 5.Bg5

```

So I switched to playing the Bogolyubov line which avoids the Slav dxc4 because my Bishop can take it with temp:

```
[FEN ""]
1.d4 d5 2.c4 c6 3.e3 Nf6 (3...Bf5 4.Nf3 e6 5.Be2 Nf6 6.O-O) (3...e6 4.Nc3 Bb4 (4...f5)) 4.Nc3 e6 (4...g6)(4...Nbd7)(4...a6)(4...Bf5) 5.Nf3 Be7 (5...Nbd7)(5...Bd6)(5...dxc4) 6. Bd3 Nbd7 (6...O-O) (6...dxc4) 7. O-O O-O

```

Btw, I tried playing the slav with white before switching to the Bogolyubov line as

```
[FEN ""]
1.d4 d5 2.c4 c6 3.Nc3 Nf6 4.Nf3 dxc4 5.a4

```

But I didn't like them that much. Maybe because I haven't read about them a lot. As you can see, there are tons of variations in the Bogolyubov line, including the Meran. It's too much! I would really appreciate it if somebody can give me either an easy line against the Semislav that avoids the Slav, or two easy lines against Semislav and slav.

# Answer
I have played Semi-Slav for about a decade as my main opening as black and I also frequently play it as white. I think it's not possible to combine all of your wishes. You would like to play 1.d4, 2.c4, 3.Nc3 but then you don't like 4.e3 or 4.Nf3. There's no good alternative to those on the fourth move (except transposing to exchange variation but that should've been done already earlier).

I suggest you could try 1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.Qb3. Game might continue 4...dxc5 5.Qxc5 Bf5 (5...Bg4 is common as well) 6.g3 e6 7.Bg2. White has a slight but lasting advantage and you don't have to know much theory.

Another a bit more rare option would be 1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.g3, after which game might continue 4...Bf5 5.Nc3 6.e6 Nh4. There's not much theory to learn, White has a slight advantage and it's not that simple to play for Black. At your level I would expect black players to be unprepared for this line.
> 2 votes

# Answer
The easiest to learn is the exchange variation. It leads to the persistent opening advantage, but doesn't offer much opportunity for a crushing win. This is the line I played when I had to face the Slav.

```

[FEN ""]

[White "?"]
[Black "?"]

1. d4 d5 2. c4 c6 3. cxd5 cxd5 4. Nc3 Nc6 5. Nf3 Nf6 6. Bf4 Bf5 (6... a6 7. Ne5)
7. e3 e6 8. Bb5 Rc8 9. Qa4 Nd7 10. Bxc6 Rxc6 11. Qxa7 Qc8 12. Qa5 Ra6 13. Qc7
Qa8 14. O-O Bd3 (14... Rc6 15. Nb5) 15. Rfc1 Rc6 16. Nxd5 exd5 17. Rxc6 bxc6 18.
Ne5 Nxe5 19. Qxe5+ Be7 (19... Kd7 20. Qc7+ Ke8 21. Rc1) *

```
> 1 votes

# Answer
1PK4 aka e4 would avoid the slav issues.

My experience says there is no real answer to what you wish were possible after you start with 1 d4 d5 and 2c4 c6 then 3 nc3.
> -4 votes

---
Tags: opening, theory, slav-defense, semi-slav
---


# Question
Title: Who is best at Fischer Random chess, humans or engines?
I know that the old good question about engines vs humans has been asked multiple times, e. g. here.

But what about random chess (aka Fischer chess or chess960)? Can humanity feel confortable about struggling machines in this game?

Do you know of plays or championships that throws any light about the question?

# Answer
You have to understand, that a top ten player is superior to an engine in the opening, because he used engines to analyze openings for many years, and because engines usually don't have an opening book on the level of the preparation of a top player.

In chess 960 you basically take away the opening book for both players and at the very top this actually benefits the engine.

So I think there can be no doubt, that engines would be similarly superior in chess960 as in normal chess. But the only Human-Engine match I know of was still won by the human player: Peter Svidler vs Baron, 1,5:0,5 in the year of 2005. Of course the big jump in engine strength only came with Rybka in the very same year 2005.
> 8 votes

# Answer
The machine, hands down.

These days the machine is so incomparably stronger than a player, that even if a player comes up with a better long-term strategy, they will still lose to inevitably missing tactics. Even if they don't outright drop material, they will overlook threats and walk into a situation where they need to concede positional advantage to not lose that material.

It's good to understand the role of Engines in human opening preparation. Players would play through various lines against a computer looking for a good position, and using the engine to spot and avoid tactical problems for themselves, while laying tactical problems for the opponent. Thus when they get to the board, if the line played out matches the studies of one player more than the other, they will instantly know which moves to play and the other is in danger of falling prey to the tactics uncovered by the machine.

This is why Fischer invented Random, to get away from excessive analysis. It is impossible for a player to memorize 960 opening schemes. Yet a computer is capable of memorizing, playing itself thousands of matches AFK. But even if you throw that opening book out (and with the new generation following Alpha Zero, this doesn't even make sense) and elite players win the strategy of the opening, yet machines will crush them in the execution.
> 5 votes

# Answer
The engine.

> It’s Chess960 time at the TCEC! (https://tcec-chess.com) **The more I watch these games, the more I feel that the gap between humans and engines is even higher in Chess960 than in normal chess.** I loved the opening phase of this game between two of the less famous engines on show. I’m not sure I would have thought of any of Black’s moves!

(Emphasis mine)
> 2 votes

# Answer
The basic difference between Chess 960 and Classical Chess is that by switching the pieces around at the start, you've in essence removed the computer's opening book. That would eliminate the potential initial advantage that had afforded, since most humans wouldn't have matched that. However, during the "960" opening and subsequently, the machine would go about business as usual, developing quickly and then searching for all possible tactics. Depending on the depth of search, it should prove superior to the vast majority of humans in that respect.
> -1 votes

---
Tags: chess-variants, chess960, human-versus-machine
---


# Question
Title: {Landa vs Zhu Chen, Bad Wiessee, 2006} Lichess giving a +4.7 to white. Why?
Here is the lichess study for the game which is often presented as study.

I am curious here, as to why White is given a strong advantage, even though the material is equal and Black has a lot more active pieces. The Black squared bishop (of Black) is far better poised than White's. The White Squared bishop (of Black) is actively involved in the attack, and the sole knight can swing in easily on c4 square, should a chance arise.

Comparatively, White's minor pieces are underdeveloped. The only advantage I can see White is having is its d-file rook X-raying the Black queen (and potentially an open file)

```
[FEN "r4rk1/pp2bppp/1np1p3/3q4/3Pb3/1QP3P1/P3PPBP/R1BRN1K1 w - - 0 1"]

```

# Answer
> 33 votes
The material balance is only temporary. After White goes ***c4***, Black will lose a piece. If ***Qf5***, White has ***f3*** trapping the bishop. All alternatives to Qf5 leave a piece unprotected (for instance ***c4 Nxc4 Bxe4 Qxe4 Qxc4 +-***)

```
[Event "Chess Calculation: Chapter 1"]
[Site "https://lichess.org/study/VFtoodiL/uG0A42Q9"]
[Date "2021.09.12"]
[Round ""]
[White ""]
[Black ""]
[Result "*"]
[UTCDate "2021.09.12"]
[UTCTime "13:24:02"]
[Variant "From Position"]
[Opening "?"]
[Annotator "https://lichess.org/@/sohamdas"]
[SetUp "1"]
[FEN "r4rk1/pp2bppp/1np1p3/3q4/3Pb3/1QP3P1/P3PPBP/R1BRN1K1 w - - 0 1"]

1.c4 Qf5
    ( 1...Nxc4 2.Bxe4 Qxe4 3.Qxc4 )
2.f3 *

```

---
Tags: tactics, positional-play, calculation
---


# Question
Title: Are chess players getting better, given the same rating?
Chess ratings are a relative thing at a particular time, just like boxing. It is not absolute, compared to weightlifting for example, in which the records keep getting broken. How would say a 1700 rated player of say 50 years ago who is no longer around go against a 1700 player of today? Does this mean that chess ratings over time have grade deflation?

# Answer
> 19 votes
> How would say a 1700 rated player of say 50 years ago who is no longer .around go against a 1700 player of today?

Speaking as a player who was around 50 years ago and was rated the equivalent of 1800 in 1973 (my BCF grading was 150 with a generally accepted conversion formula of ELO = BCF x 8 + 600) and is rated 1718 today I'm pretty sure I would beat my 17 year old self.

OK, the me of 2021 is probably not very objective but I am sure that if I managed to reach an even endgame against my 17 year old self I would be a very strong favourite. The reason being that in 1973 almost all the chess I played was at a time control of either 30 moves in 75 minutes or 36 in 90 with adjudication after 3 hours play. The 17 year old me hardly ever played an endgame and so wasn't that good at endgames.

That kind of time control was the norm in England 50 years ago and probably in much of the non-Soviet world. Weekend tournaments where large numbers of people played 3 full games a day with a time control of all the moves in 1 hour didn't come in until the mid to late 70's.

> Does this mean that chess ratings over time have grade deflation?

From my personal view absolutely, yes. However my single example of personal experience is highly subjective and one case is meaningless.

To get a more objective view of whether there has been rating inflation or deflation I think we have to look at historic data. There is FIDE rating data available going back to 2001 on the download page of the FIDE rating website and back to 1971 (unofficial data back to 1967) on the Olimpbase site. These data can be downloaded and analyzed to get more meaningful evidence.

Comparing today with 1971 is problematic because in 1971 there was a rating floor of 2200 (nobody under 2200 was listed) so there were only 547 players and obviously nobody with a FIDE rating of 1700. However we can try and maybe also, more meaningfully compare today with 10 years ago.

The January 1971 list is here on Olimpbase. There we can see that the highest rated player, Bobby Fischer, is at 2740, more than 100 points lower than today's number 1, Magnus Carlsen on 2847. There are 16 players at or above 2600, 82 at or above 2500 out of 547 at or above 2200.

The comparative figures for March 2021 are 264 above 2600, 946 above 2500, 3111 above 2400 and 17334 above 2200.

**January 1971**
Players above 2600 = 16 (2.9% of over 2200s)
Players above 2500 = 82 (15% of over 2200s)
Players above 2400 = 278 (50.8% of over 2200s)

**March 2021**
Players above 2600 = 264 (1.5% of over 2200s)
Players above 2500 = 946 (5.5% of over 2200s)
Players above 2400 = 3111 (17.9% of over 2200s)

To me that looks like it is comparatively much harder today to get to GM / elite level than it was 50 years ago but the difference in sample sizes detracts somewhat from the percentages. And, of course, it doesn't say much about what is happening at the 1700 level.

If we go back 10 years and compare numbers and percentages (using total rated players) at 1700, 2150 and 2600 we get:

**March 2021**
Total rated players = 363590
Players rated above 2600 = 264 (0.07%)
Players rated above 2150 = 29392 (8.1%)
Players rated above 1700 = 169425 (46.6%)

**March 2011**
Total rated players = 126693
Players rated above 2600 = 223 (0.18%)
Players rated above 2150 = 29575 (23.3%)
Players rated above 1700 = 111529 (88%)

Again it looks like it is relatively harder today to get to a higher rating than it was 10 years ago but that might just be a reflection of the expansion in the number of FIDE rated tournaments for lower level players. But, yes, it does look a bit like rating deflation to me.

# Answer
> 16 votes
Everybody seems to agree that "ELO inflation" is real (I found an article from 20 years ago claiming this exists)...except scientists. Here is a 2011 paper that vehemently denies the phenomenon; the abstract says that only little inflation happens, and the players really get better. https://ojs.aaai.org/index.php/AAAI/article/view/7951

# Answer
> 8 votes
This is actually a very interesting question! Actually, there were not many 1700 rated players 50 years ago because most ratings started above 2000. With the evolution of computers, it is very plausible that a 1700 player now is much stronger than 50 years ago.

Nowadays, openings are spoon-fed and many references are available whereas those days every day you get someone playing novelties. And players had to read books and analyze on their own. Imagine having to learn Russian to learn about your favorite opening.

But it is important to note that playing styles have also evolved. 50 years ago, as openings analysis was limited, players depended on attacking and pressuring the opponent, whereas nowadays players have many resources( thanks to engines ), and attacking is very dangerous.

Talking about grade deflation, currently, there are a lot of players and a very high gap in terms of skill compared with an active Grandmaster. Considering the number of players and mix of people involved in playing chess, there is no doubt that grade deflation will keep on continuing. Although this can have a negative impact on bringing new players into the field.

Finally, I would like to point out the strength of players differ according to the geographic region too. For instance, countries in south Asia have a lot of skillful yet underrated players.

But in general, a 1700 player now has the upper hand over a 1700 player 50 years ago. Back then chess was an ART of its purest form. Nowadays computers have molded it into something completely different.

# Answer
> 5 votes
According to Dr. Ken Regan, no. Players at the same rating even across different eras are approximately equal skill. In other words today's Hikaru Nakamura is stronger than the 1972 Bobby Fischer. This shouldn't be too surprising, given that Nakamura was able to study Fischer's games and learn from Fischer, but not vice versa.

The methodology is by matching the players' moves against computers.

> Only players alive during the same period can play each other. But since Regan's method compares moves to a common standard (the engine), rather than the results of games, he can objectively relate player abilities across eras. What he found was that rating inflation does not exist. Between 1976 and 2009, there has been no significant change in IPR for players at all FIDE ratings. Figure 5 shows, for example, how the IPR for players rated between 2585 and 2615 has remained relatively constant over time. Today's thousands of grandmasters and dozens of players rated over 2700 indicate a legitimate proliferation of skill. Thus one may conclude that Hikaru Nakamura's peak FIDE rating of 2789 beats Bobby Fischer's peak of 2785 for best American chess player of all time, and Magnus Carlsen's peak rating of 2881 places him as the best human chess player of all time.

Source

# Answer
> 2 votes
My pet theory is that players in isolated communities (*e.g.* from different eras, or from one platform to another) can be compared by considering the probability of a draw. We see in high level play that draws are quite common, with more than half the games ending in a draw. High skill players are less likely to make mistakes that lead to a loss. In my study of games played, I found that the probability of a draw was increasing in Elo for evenly matched players. This kind of analysis might be usable to compare current to past players.

---
Tags: rating, history, elo, statistics
---


# Question
Title: Abbreviations like 't', 'm', 'zt', 'sf' in chess databases
I am just cleaning up the `Event` and `Site` headers in the games in my chess database.

There are a lot of abbreviations there. I am relatively sure about the following:

* `of`, `qf`, `sf` and `f`*octo final*, *quarter final*, *semi final* and *final*.
* `zt` and `izt`*zonal tournament* and *interzonal tournament*.

But I could need help with these:

* `tt`*Transnational Tournament*? *Training Tournament*?
* `m` (also: `mt`) – *Masters*? *Match*? *Men*? *Memorial*?
* `Tch`*Transnational Championship*?
* `It`*Invitational Tournament*? *Italia*?

Any hints are appreciated.

# Answer
**tt** in databases means "team tournament" : you can find it for teams events, for instance the French team championship or Olympiads.

I suspect **Tch** to be similar ("Team championship") but I wouldn't be affirmative.
> 2 votes

# Answer
Wikipedia says `TT` is *Transposition Table*...

When the search encounters a transposition, it is beneficial to 'remember' what was determined last time the position was examined, rather than redoing the entire search again. For this reason, chess programs have a transposition table, which is a large hash table storing information about positions previously searched, how deeply they were searched, and what we concluded about them. Even if the depth (draft) of the related transposition table entry is not big enough, or does not contain the right bound for a cutoff, a best (or good enough) move from a previous search can improve move ordering, and save search time. This is especially true inside an iterative deepening framework, where one gains valuable table hits from previous iterations.

`IT` seems to hint at *Invitational Tournament*, though I cannot confirm this.
> -1 votes

---
Tags: database, terminology
---


# Question
Title: List of records for youngest superGMs since 1950? (or 1970 or whenever FIDE started rating people. or basically after 2700s after Fischer)
On Wiki, we have the List of youngest grandmasters since 1950. What about superGMs (defined anyone who has reached 2700+ peak FIDE standard) instead of GMs: where can I find a list for the youngest to pass 2700+?

**Notes**:

1. The above link obviously doesn't answer the question directly, but I guess the members of my required list are a subset of the list of everyone who's gotten 2700+ peak standard FIDE rating.
2. I guess the list begins with Bobby Fischer ('first player to achieve 2700+ rating') and ends with Wei Yi ('Youngest player to reach a rating over 2700').

**So I guess the list is gonna look like...**

1. Bobby Fischer - (insert rating obtained for 1st time over 2700) - (insert month and year when this rating was obtained) - (insert age for when this rating was obtained)
2. ?
3. ?
4. Wei Yi - (insert rating obtained for 1st time over 2700) - (insert month and year when this rating was obtained) - (insert age for when this rating was obtained)

---

**Bonus**: youngest female superGMs

1. Judit Polgar
2. N/A

# Answer
> 0 votes
From reddit:

1. Fischer (28y 3m 23d) 1971 Jul (World #1)
2. Karpov (22y 11m 9d) 1974 May (World #2)
3. Kasparov (20y 8m 19d) 1984 Jan (World #1)
4. Shirov (19y 0m 3d) 1992 Jul (World #4)
5. Kramnik (18y 0m 6d) 1993 Jul (World #4)
6. Carlsen (16y 7m 1d) 2007 Jul (World #17) --\> appears to be the biggest gap so far
7. Wei Yi (15y 8m 29d) 2015 Mar (World #44)

# Answer
> 1 votes
My research tells me, that FIDE has only started rating players from 1970/71 on.\[\]

##### Background Knowledge

There are multiple databases listing players, for example *OlympBase*, which contains the ratings of all (?) FIDE-registered players from 1971-2001, after which year, one can consult the current FIDE-list (which doesn't store ratings before then, apparently).
Before Fischer's time, I have found four players above an Elo of 2700\[\]¹: José Capablanca, Michail Botvinnik (GM with 39), Emanuel Lasker, Michail Tal (GM with 29). But these rating numbers are somewhat problematic, since before 1970, only *historic elo numbers* are availible for us; remember, FIDE only started using Elo in the early 70s, the german Wikipedia tells me, that Aljechin, for example, had a peak (historical!) Elo of **2860**, in May of 1931, which is higher than Kasparov's highest ever Elo of **2851**. There is a website, called 2700chess, which lists all players above a rating of 2700, but again, only from 1970/71 onwards, starting with Fischer. Consider this a little background knowledge.

##### Serious lists?

I doubt, that there is any official list or database, listing grandmasters specifically since 1950 sorted sorted by youngest age. The closest I have come to such list is a Youtube video by the very popular chess-website chess.com, with some sources in it's video description. Here you go: Youtube video.

¹ I would like to point out, that Tsar Nicholas II. awarded the then informal title "Grandmaster" to the five best players in the 1914 Chess Tournament in St. Petersburg. That would make Capablanca GM with 26 years, Lasker with 46 years and Aljechin with 22 years of age.

I'm not too familiar with the mechanisms, with which others can modify my answer, but if someone find something of interest, he or she should go ahead, and edit my answer (if possible).

---
Tags: history, statistics, records, titles, super-grandmaster
---


# Question
Title: Where can I play against specific openings?
Is there a website where you can play against real people with an opening already installed by default? For example, I want to play against the English opening, but my opponents rarely play it, so I want to practice somewhere.

# Answer
If you want, Chess.com allows you to play from a custom opening position against a computer, which you can choose your level. If you need help with it, go here. You can also send a game to a friend.

https://support.chess.com/article/684-how-can-i-play-the-computer-from-a-custom-position

Lichess does a similar thing. Create your personal board, and press continue from here to play with a computer or a friend.
> 8 votes

# Answer
Lichess also has several thematic tournaments throughout the week. As an example take a look at this thematic Italian game arena tournament:

When you open the tournament, the opening is mentioned in the upper left corner if there is one:

It is a link so you can click it to see the mentioned opening.

Alternatively you can create your own tournament with a opening of your choice. For that just go to the create tournament area and set the starting position:

In that box you have to place a FEN string. For the English opening considering only `1 C4`, you can use the following fen:

`rnbqkbnr/pppppppp/8/8/2P5/8/PP1PPPPP/RNBQKBNR b KQkq - 0 1`

Regardless you can create any fen of your choice with the lichess analysis board tool or the opening explorer
> 11 votes

# Answer
There are theme tournaments on ICCF. Example for the Alapin variation of the Sicilian. However, it is correspondence chess, which might not be your cup of tea.
> 1 votes

# Answer
echecsemail.com allows you to create games and tournaments dedicated to specific openings.
> 0 votes

# Answer
Check out the Maia chess bots on Lichess, e.g. `maia1` and `maia5` (there are multiple bots with different elo ratings). They're designed to play like humans. You can challenge them to a game from any position using From Position.
> 0 votes

# Answer
i could swear there's a feature in chessdotcom that allows you to play correspondence chess from a certain opening...wait yeah see here:

>

you can even see what you're getting into:

>

idk what sites have live versions these. but man before i quit chess for 9LX i sure wished there were live versions of these.

so far the answers talk of tournaments or bots. the bot option sounds lame, but idk if it works for you then go ahead. the tournament thing seems like the closest we're gonna get for now. but i think it's a pretty good option. i mean, not sure what a queue for specific openings would look like.
> 0 votes

---
Tags: opening, training, websites
---


# Question
Title: List of records for youngest superWGMs since 1950?
On Wiki, we have a list for List of youngest grandmasters since 1950. What about superWGMs (any female player who has reached 2500+ or has become GM, whether or not they were actual WGMs so as to include Judit Polgar) instead of GMs?

Note 1: I use 2500 as the mark for superWGM based on this and this.

Note 2: I'm guessing this is a different question from this (List of records for youngest female grandmasters since 1950?) because you could reach 2500+ without getting the norms right? But eh it's probably the same answer anyway.

# Answer
Ah here: the ff have reached 2500+ according to this but aren't GM:

1. Lela Javakhishvili
2. Almira Skripchenko
3. Qin Kanying
4. Svetlana Matveeva
5. Polina Shuvalova

Since all the peaks are 2500-2502, I'm just gonna assume the time they got the peaks is the 1st time they got the peaks sooo...

1. Lela Javakhishvili - 2500 in March 2010 at the age of 25
2. Almira Skripchenko - 2501 in January 2003 at the age of 26
3. Qin Kanying - 2501 in July 2000 at the age of 26
4. Svetlana Matveeva - 2502 in January 2004 at the age of 34
5. Polina Shuvalova - 2507 in August 2021 at the age of 20

These are all over 15 years of age and all after Judit Polgar became GM (and thus superWGM).

**Conclusion**: The superWGM list is, for now, **the same** as the female GM list.

---

**Update**: Ok so there are also females who obtained GM without reaching 2500+ like Peng Zhaoqin. I don't think this affects either the superWGM list or the female GM list. If anyone has any idea, then please let me know.
> 1 votes

---
Tags: history, statistics, records, titles, women
---


# Question
Title: Good online database, or do I need ChessBase?
I just bought a premium account at chessbase.com, including full access to tools like the Live Database. I have to say, I'm a little bit disappointed by the features they provide.

My question is, is there a better online analysis/preparation tool that I can just open anywhere in a browser, or do I need to install the ChessBase program to get more features?

---

More specifically, this is one feature that I miss in the Live Database:

Find all games for a specific player, as either white or black, and for each position, see which moves they made (and the result of those games).

Basically, the possibility to filter the "Live Book" window on a specific player with a specific color.

I assume this can be done in the ChessBase program, although I have never actually tried the program.

---

I also wonder, say I go ahead and buy the ChessBase program. Is it still necessary to have the premium chessbase.com account, or is that all included when I buy the program?

# Answer
Take a look at chesstempo. You can use their online database free up to so many moves and then they want you to pay to search deeper. I used to use chesslab.com which was great for searching positions, but it uses a vulnerable version of flash -- if you can deal with that it is a nice resource. chess-db.com claims the biggest database (which is not necessarily good, do you want the kids under 12 tournaments?). The site is fast and has a lot of features.
> 3 votes

# Answer
Chessbase is by far the best preparation tool - almost all of the top players use it for a reason (as well as most serious players in general).

I wouldn't recommend using the online version though, for a couple of reasons. As you have found, a few features seem to be missing. In addition, having wifi access is required if you want to look someone up (which can be inconvenient if you're at a tournament and need to prepare for an opponent quickly).

The ChessBase program is the way to go. I've been using it for around 10 years now and it's been great. It's straightforward to look any player up in any database. The program also supports the top chess engines (like Komodo, Stockfish), and allows you to save your games in databases.

The normal version would be fine. The more premium versions give access to a few perks, but I think it's overrated.
> 2 votes

# Answer
A really good preparation tool that I use is 365chess. Although it is not better than ChessBase since it offers less features and games, it is online and free, the only requisite to access their big database is to register an account. You can filter games by player, but searching by player and position is a bit awkward, you may need to first go to his games and play out the moves to reach the position you want.
> 0 votes

# Answer
I have ChessBase 16. It has very helpful features but it is costly. If you like the GUI (Graphical User Interface) do not go for it. It is good if you are of the following levels;-

Intermediate, Advanced, Expert & Professional

ChessBase is for serious players who want to improve
> 0 votes

# Answer
Chessbase by itself however is pretty useless. You need a decent reference database behind it eg; Mega Database 2020x. My Chessbase setup is the Mega Database 2021, Opening Reference Database 2021 and the Correspondance Database 2020 (which I reference the most). I addition to this I have a script to collect games of all titled players on Lichess and Chess.com that are 10 minute or above time controls. This gives me a comprehensive database for reference purposes. Storage is a bit of an issue that being said.

I utilise Chessbase to analyse every game I play, explore new opening ideas and I absolutely love it. That said, its an expensive set up. If you haven't got disposable income it effectively prices you out. I even have my own databases for Opening Repertoires , studies etc

Ultimately though Chess.com , Lichess have comprehensive databases that are sufficient for 90% of use cases in my opinion.

I can't ethically suggest to someone they should invest the $500USD to get chessbase set up properly , but if you take chess seriously want to improve and support the developers of the tool , I would say it a very good tool.

There are free-alternatives (SCID as an example) however you need to build your own databases which can be quite hard. There is a website called https://theweekinchess.com/ which is quite good for this , which if you are patient or a adapt scripter you could collect all their archives and build your own database. Just an idea.

Edit: Happy to write up a quick powershell script to help download all the twic archives if you'd like.
> 0 votes

# Answer
Chess Assistant = cheaper, more package combinations, superior analysis functions. Chessbase = Easier searches+saving+use+flexible membership, not buggy+superior support, uploads newest games on starter package, on-line latest games on all. As and ex-2100 chess player I find TONS within CA I relish but actually struggle and become frustrated with, whilst wishing for CB to reach those multiple+individual depths, if far more comfortable from a more reliable and quality+workable fact.
> -1 votes

---
Tags: chessbase, preparation
---


# Question
Title: Smallest number of moves needed to mate a lone Black king on e8 with all White pieces
Imagine that all White pieces are in their initial position and Black only has their king on e8. What is the smallest number of moves needed for White to give checkmate?

# Answer
There seem to be many ways to mate in 6. That is the best I found. Here is one.

```
[FEN "4k3/8/8/8/8/8/PPPPPPPP/RNBQKBNR w KQ - 0 1"]

1.e4 Ke7 2.Qg4 Kd6 3.Qg7 Kc5 4.d4+ Kb4 5.Bd2+ Ka4 6.b3#

```
> 4 votes

---
Tags: problems
---


# Question
Title: What is the chess position with biggest X, where no matter what legal move black/white does, a specific player will be mated at a max X moves later?
There are positions where no matter what legal move black or white does during this sequence of moves, an specific player, will always be mated after X moves (sometimes earlier, but after X moves its a certain thing).

What is the position with biggest value for X?

# Answer
The longest known sequence is 22 plies long.

```
[Title "Alexey Khanyan, Tim Krabbe's Website Diary Entry #267 2008, Mate In 11"]
[FEN "4Q2Q/4r3/4n1n1/1bbK1krn/RR1RR1RR/2qn1R1n/4n1nN/Q3Q3 b - - 0 1"]
[startflipped ""]

1... Ng2f4+ 2. Rfxf4+ N2xf4+ 3. Rgxf4+ Nh3xf4+ 4. Rhxf4+ Ndxf4+ 5. Rxf4+ Nhxf4+ 6. Rxf4+ Ngxf4+ 7. Rxf4+ Nxf4+ 8. Rxf4+ Kxf4+ 9. Qee5+ Qxe5+ 10. Qaxe5+ Rgxe5+ 11. Qxe5+ Rxe5+ 12. Qxe5#

```

Source: Diary Entry #267
> 7 votes

# Answer
We don't know-. For instance, it's entirely possible the starting position is just mate in 10000.

However, the obvious answer if we modify the question slightly to the longest forced mate known can be found in an endgame tablebase (a collection of endgame positions, with evaluations and time to mate). The Syzygy tablebase is an example. The current record (ignoring the 50 move rule) is 546 with this position (as mentioned on Wikipedia). Most tablebases ignore the 50 move rule, and as such I cannot find any note on the longest forced mate with the 50 move rule.
> -1 votes

---
Tags: problems, records, forced-move
---


# Question
Title: Position Analysis - Win or Draw - Efimeko v Rublevsky 2009
Is the current position winning or equal , and with the perfect play what would be the resulting position.

```
[Event "Karpov Poikovsky"]
[Site "Poikovsky RUS"]
[Date "2009"]
[Round "4"]
[White "Efimenko"]
[Black "Rublevsky"]
[Result "*"]
[SetUp "1"]
[FEN "b1r3k1/7q/5BpQ/8/4P3/6PP/2P3BK/8 w - - 0 1"]

```

# Answer
> 1 votes
So perfect play is a tricky so allowed the engine to play it out.

**Analysis**

A review of the position using StockFish 14 indicates that White is winning with a positional advantage of +-1.51. This was discovered at a depth of 40. I ended up running this to a depth of 120 at which point the position was drawn. I went backwards to find the critical position where this occurred and stepped a bit more forward for explanations sake.

```
[Event "Karpov Poikovsky - Analysis"]
[Site "Poikovsky RUS"]
[Date "2009.06.06"]
[EventDate "2009.06.03"]
[Round "4"]
[Result "1-0"]
[White "Zahar Efimenko"]
[Black "Sergei Vladimirovich Rublevsky"]
[ECO "B45"]
[WhiteElo "2682"]
[BlackElo "2702"]
[SetUp "1"]
[FEN "b1r3k1/7q/5BpQ/8/4P3/6PP/2P3BK/8 w - - 0 1"]
[PlyCount "54"]

1. Qd2 Qf7 2. Bd4 Kf8 3. h4 Kg8 4. Qh6 Qh7 5. Qg5 Qf7 6. h5 Kh7 7. Bh3 Rxc2+ 8. Kg1 Bxe4 9. hxg6+ Bxg6 10. Bg4 Rc4 11. Qh4+ Bh5 12. Bxh5 Rxd4 13. Bxf7+ Rxh4 14. gxh4 Kg7 15. Bd5 Kg6

```

**Conclusion:** The *position is drawn* and with perfect play White has no ability to convert this to a win.

If you look at the above at move 14. it become apparent what the issue is. Black has only a King, but white has a Bishop (Light Squared) , Pawn and King. The pawn is on the H file. White cannot stop the black king retreating to the h8 square where it can force a stalemate or draw by three fold repetition.

**Full Game that was actually played**

```
[Event "Karpov Poikovsky"]
[Site "Poikovsky RUS"]
[Date "2009.06.06"]
[EventDate "2009.06.03"]
[Round "4"]
[Result "1-0"]
[White "Zahar Efimenko"]
[Black "Sergei Vladimirovich Rublevsky"]
[ECO "B45"]
[WhiteElo "2682"]
[BlackElo "2702"]
[PlyCount "127"]
[FEN ""]

1. e4 c5 2. Nf3 e6 3. d4 cxd4 4. Nxd4 Nc6 5. Nc3 d6 6. g3 Nf6 7. Bg2 Bd7 8. O-O Be7 9. a4 O-O 10. Nb3 Rc8 11. f4 Na5 12. Nxa5 Qxa5 13. Kh1 Bc6 14. Bd2 Qa6 15. Qe1 b6 16. Qe3 Rfd8 17. Qd3 Qb7 18. b4 Qa8 19. b5 Bb7 20. Qe2 Rc7 21. a5 bxa5 22. Rxa5 Qb8 23. Rfa1 Rdc8 24. Qe3 d5 25. Qxa7 d4 26. Qxd4 Bc5 27. Qa4 Bb6 28. Ra6 Nd7 29. Rxb6 Nxb6 30. Qd4 Rd7 31. Qf2 Qc7 32. Be1 h6 33. h3 Qd8 34. Kh2 Nc4 35. Na4 Rd1 36. Rxd1 Qxd1 37. Nc5 Ba8 38. Bc3 Qd6 39. Bd4 Qb8 40. Qe2 Qxb5 41. Qg4 g6 42. Qh4 Qe8 43. Qxh6 e5 44. fxe5 Nxe5 45. Nd7 Qxd7 46. Bxe5 f6 47. Bxf6 Qh7 48. Qd2 Qf7 49. Bb2 Qe6 50. h4 Qe7 51. Qd3 Re8 52. Qd4 Kh7 53. c4 Rd8 54. Qc3 g5 55. Qa5 gxh4 56. Qf5+ Kg8 57. Bf6 hxg3+ 58. Kh3 Qd7 59. Bxd8 Qxd8 60. c5 Qc7 61. Qg6+ Kf8 62. Qd6+ Qxd6 63. cxd6 Kf7 64. e5 1-0

```

---
Tags: analysis
---


# Question
Title: What is the earliest possible age to start teaching children how to play chess?
My daughter is 4 years old, and she plays checkers very well for her age. She asked me if she can learn how to play chess too. So I am interested in what is the best age to start teaching her. Is it too early to do this? Does anyone have any experience?

# Answer
Depending on several factors, the age to start teaching a child to play chess can vary.

The mere fact that she asked you how she can play chess is a good sign that she is interested in learning. Interest is one of the key factors because we don't want to force-feed them the game. If I had to pick an age, I would say 4 is a good age, but it depends also on maturity. I would also say not to expect too much and let her have fun. A great place to start is https://www.chesskid.com

My 2 (almost 3 year old) stumbled upon `Chessmaster` by accident. He was more intrigued by the movie type intro to the game rather than the actual game itself, nevertheless, he remained interested and knows all the names of the pieces, but that is about it. He knows that it is a game, but if I tell him something like "Take the knight", he will take a pawn on some square and go all the way across the board and take it, lol, so based on my own experience, 3 seems to be too young in most cases. I have really yet to see 4, but when my kid reaches 4, I guess I will find out, but based upon his reaction now, I think he would have a good grasp of the rules by age 4, maybe earlier. As for now, I just let him have fun.
> 55 votes

# Answer
You can teach your daughter how to play the game at any age, especially if she is curious. I remember asking my father to teach me around the age of 4, and while I was not very good at the game, I was at least able to understand how the pieces moved. It became my favorite game to play as a child, and I would constantly challenge my father to games, and even win some (I'm certain he let me win). If your daughter is asking, you should teach her.
> 24 votes

# Answer
Any age, IMO. My father taught me to play at about 6.

Oh, and lead by example - take your kid to your local USCF chess club and become a member. Play, show good sportsmanship, etc etc.

Chess is empowering for kids; as long as they are polite they can **kick the crap out of adults and people reward them for it**, lol.
> 23 votes

# Answer
Whenever she wants to learn. And let her choose the pace.
> 16 votes

# Answer
I've heard of high level chess players starting at a young age. One such story is Yelena Dembo. She played her first rated tournament at 3 years 9 months: http://yelenadembo.com/about-me

But there are plenty of high level players that start later, so I wouldn't consider early play a requirement to reach that level. Not that that is necessarily your goal, ha!

I think the two key pieces are 1. interest and 2. attention span. If 1 is there but not 2, you should definitely start with some mini games, as recommended in another answer.

I sincerely hope I can instill an interest in mine when she's a bit older--partly selfishly as I'd like to have someone to play with, and it would be great if we could go to tournaments together. But I also believe that chess is a good developmental tool that teaches critical decision making, attention, sportsmanship, pattern recognition, among many other things, I'm sure. I've purchased the rather new "Chess is Child's Play" book, which I haven't looked at much so far--it has exercises for 2-4 years old, and instructions for teaching 4+.

My 16-month-old can't even lift my triple-weighted chess set yet (it's all in one bag--probably weighs about 5 lbs). She very much likes to take the pieces out (to give them to me) and I show her how they set up on the board. Then she likes to pick them up and give them to me to put them back in the bag (we do this a couple times a day--she goes over and points at the chess set when she wants to play with it). She likes the knights, especially. Little horses! If only there were a set with ducks as pawns, or something. I think that would be a hit.
> 10 votes

# Answer
My daughter just turned 4 and she knows how every piece moves, which is great IMO, but it is frustrating at times because I wish I could teach her more things at once. However, I do not force her, it is actually the other way around There is not a single day that she does not ask me something about the pieces or anything related to the game.

She knows what is a rank and a file but she doesn't quite understand what is diagonal, she is starting to locate coordinates on the board but that's about it.

I bought her a plastic chess set with figurines instead of the classic Staunton pieces, that way the queen actually looks like one, and so does the king and the rest of the pieces, believe me, that for a kid at that age it helps a lot, she can now set up the board and pretend to play with her 2 yr old sister, until the imaginary fight between the two sides gets real.
> 8 votes

# Answer
As early as `he` or `she` can. But do not force it upon the child. Just show the path. The child if interested (s)he will pick it up soon or a bit later in their life.
> 7 votes

# Answer
My son is five years old, and he is an expert at making stuff with Legos like blocks and had learned preschool stuff before most of the other kids his age (in my locality). He also speaks/converses in 3 languages quite well. With this, I assumed he would be good at chess.

Two months ago I introduced him to chess, explained the rules, and within 2 days and 7-8 games, he managed to learn all the rules (I withheld en passant and castling). By game 15 he was moving all pieces correctly. Initially he had a problem understanding why the rook, which is smaller (shorter) than a bishop, was not to be exchanged with it.

Also, he would be very careless in keeping pieces, especially knight and queen, where it would be at the risk of being taken. I tried training him with only few pieces on the board and showing how not to keep the pieces where it can be taken. Unsurprisingly he was very good at identifying the threats. I guess it is because there are only 3-4 pieces on board, and that makes it simpler to observe.

Its been quite a lot of games since then, almost 40-50, but he still does not keep supporting pieces when keeping/moving them in the front under threat. I notice that he is sometimes, or most of the time, interested in just moving his pieces, and does not pay attention to the opponent’s move. He told me a few days ago that, and said “How come you are always winning?!”

He has actually not learned yet how to do addition and subtraction in school, and maybe that is why he does not understand losing 2 pieces in exchange for 3 is not good!

I am almost concluding here that maybe he should have grasped the concept of profit/loss by understanding addition and subtraction before I taught him chess, now I have reduced the frequency of play, maybe none or 2 in a week.

I think I will stop it completely and reintroduce it when he has learned addition/subtraction well and/or he is around 7 or 8 years old.

As with Garik’s tip, maybe I will teach him checkers!
> 7 votes

# Answer
I taught my younger sister at 4. Partly because she was extremely good at adult-type jigsaw puzzles, I was sure her pattern recognition capabilities were up to it, and her ability to be still and concentrate for a reasonable amount of time. I would look for that sort of sign of readiness.
> 7 votes

# Answer
If your daughter "plays checkers very well and asks you if she can learn to play chess also," she's ready. Some people are ready at age 4, others aren't ready at age 40. It all depends on the person. It's best if you let THEM tell you (as your daughter has) when they're ready.

Jose Raoul Capablanca learned to play chess at age four, and became world champion.
> 7 votes

# Answer
I learned to play around two and beat my mom in my first game. I never became particularly good at chess - maxing out around 1800 as a late teenager after a couple years of serious play. From my own experience I'd recommend against using success as a toddler as a predictor of future playing ability.
> 5 votes

# Answer
As young as possible, but start them with a simpler board: A King and a few pawns. When ready, add a Rook. Slowly work the pieces in, so they can grasp each piece's role in time.

A full board is pretty overwhelming to any beginner.
> 3 votes

# Answer
As with anything, its most important to make the game a **positive** experience.

I also recommend taking her to a chess club where she might be able to play people around her age (though not necessarily at her level), if she does get hooked I really recommend getting a tutor of some sort and having her play competitively (obviously you should not force this on her, but you should let her try it at least once).

It really is best to start playing young not only because of the developmental factors (neuro-plasticity etc etc) but also because you will never have as much **time** as you do when you are a child, to enjoy chess (unless you play professionally).
> 3 votes

# Answer
In my opinion, it is possible to teach children chess from as early as two years old. It all depends on what results you expect to see and at what age. The goal of a chess game is to win by defeating your opponent's army. The concept of winning and defeating an opponent is not trivial and the understanding of this concept comes at different ages for different people. Explaining the rules of the game (how the pieces move) can be done at any age. Yet explaining the concept and driving force is a bit more complex.

In general, the earlier you begin learning chess, the better you become at chess. At the same time, you need passion to drive your learning forward. So becoming a good chess player is a combination of passion and practice. While teaching the rules will be simple, becoming passionate about chess is a much more complex process. Certainly, the odds of becoming interested in chess are greater if the child already has some understanding for logical thinking, cause and effect, basic mathematical knowledge and perhaps experience in other games (e.g. checkers). Having this in mind, perhaps the age of 6-8 is more ideal.

My advice would be to keep a full sized chess board at home and play with family and friends at home on a regular basis. If you have chess as part of your daily life, an interest for learning it will be sparked sooner or later. Learning by example is powerful and usually works well in practice. If chess becomes associated with positive emotions and moments, then the chances of becoming interested in chess should be pretty high.
> 2 votes

# Answer
In some countries, chess is a part of school subjects. According to research, students who started to play chess got a higher IQ.

Chesskids.com is a wonderful chess site dedicated to kids.
> 2 votes

# Answer
It depends on the person. I use to teach chess to children and some very young kids could not learn chess while others could. Because of this, I am impressed by the people above who learned how to play chess at two.
> 2 votes

# Answer
My daughter started at her Montessori at 3.5. She is 5 now and is happy playing someone on the board by herself (and I coach her from time to time). We have chess play-dates with other 5/6 year olds where they do chess for an hour followed by physical play for 1-3 hours. I teach kids chess as a hobby and I know I once started a very active 3 year old boy and he lost interest very fast. It does vary from child t child but I think 4 would be a safe age based on my experience, provided you let them win some every now and then:)
> 1 votes

# Answer
When I learned chess as a kid we started with pawns only with all white pawns on 2. row and all black pawns at 8. row). The pawn moved as in a normal game of chess and the winner was the one who first brought a pawn to queen promotion (though no queen was brought into play the game just ended here).

Next step was to bring in the knights. The setup was: Black knights on b8 and g8 and now only 4 white pawns at c2,d2,e2 and f2. The goal for white was again to get a pawn to queen promotion and the goal for black to capture all white pawns before the reach queen promotion.

In the next steps the black knights was replaced with

1. the bishops at c8 and f8
2. the rocks at a8 and h8
3. queen at d8

all these variants had same goal and white pawn setup as with the knights.

I think these games gives a good insight into the movement and the strength of the pieces and how the work together - you can of course make your own variations with more or less pieces also.
> 1 votes

# Answer
I believe that the best age is to start at 4 or 5. This is because this age is when children have a long enough attention span and can learn seriously.

First, start off with a game where there are only pawns. Slowly teach the child the rules, and then start a game, where the child loses. Do this again, but don't let the child be discouraged by losses. Then, play easy and lose a game on purpose. Repeat these steps until the child plays reasonably well. Continue on until mastery.

Repeat processes for knights, bishops, rooks, and queens. Then, start combining these pieces with the pawns individually.

Once this is done, start off again with two knights and 8 pawns. Then, keep adding pieces until the 'normal' chess setup is reached.

From this point, I recommend the Chesskid courses as suitable.
> 1 votes

# Answer
The best age is probably any time she shows interest. As a child, if I was interested in something, I'd only be interested in it for a month max (if no one had formally introduced me to it) before I moved on. If your daughter shows interest, then feed that interest, otherwise she might move on (and have lost a great opportunity).
> 1 votes

# Answer
I was a very self-serious kid, who really wanted to learn the game. My elementary school had an after-school program where I got to play with my peers and learn from "Older kids" (probably teenagers). I was eager to study and learn and figure out what the pieces meant, but other kids my age were less engaged.

Case in-point, in one of our casual tournaments we held I won third place because one kid did some illegal moves, and one kid thought that you could flick pieces at other pieces and if they got knocked over they got removed bowling-style. The kid was probably six or seven, but just wasn't interested.

Something which kept the game kind of fun was chess variants; once the kid learns the rules set up puzzles and games. See if they can win with only certain pieces or certain positions. This type of learning reinforces rules and (if they are the puzzle-solving type) gives them more immediate feedback for what they are learning.

You can teach someone chess very young if you introduce them to it one rule at a time, and through a way which is engaging (not just 32 pieces on the board standard variant chess day in and day out). Other people have suggested some good softwares for this, but much of that can be done over-the-board. Judging by the earlier responses on this post: they are well on their way to learning. Just thought I would add that in my experience, age matters less than maturity and intention.
> 1 votes

# Answer
The minimum is 3 years old at most: Misha Osipov (3 yo) vs Anatoly Karpov (2016).

(not sure terminology here...did i just describe the infimum aka greatest lower bound? idk lol)
> 1 votes

---
Tags: learning, children, scholastic-chess
---


# Question
Title: Why don't people play the Englund Gambit?
```
[FEN ""]

1. d4 e5

```

I have been playing this gambit for over 8 months with extensive analysis and have come to the conclusion that it is a very playable opening and, in many cases, black can achieve a position that gives him attacking chances. Why don't people play the Englund Gambit then?

# Answer
> 12 votes
A part of it has to be that white doesn't have to keep the pawn.

```
[FEN ""]
1. d4 e5 2. dxe5 Nc6 3. Nf3 Qe7 4. Nc3 Nxe5

```

`4.Nc3` is actually the most popular move in lichess database. Black Queen is placed a bit strangely on e7, it is blocking the development of the dark-squared bishop and not supporting the d-pawn if it wants to move to d5. Black can double white pawns with Nxf3, but white has plenty of activity to compensate for it. White has many promising continuations, but here is one:

```
[FEN ""]
1. d4 e5 2. dxe5 Nc6 3. Nf3 Qe7 4. Nc3 Nxe5
5. Bf4 Nxf3+ 6. gxf3 Qb4 7. Qd2 d6 8. e4

```

This position is not exactly a gambiter's dream, since white is much more active, and also stockfish gives it 1.5.

# Answer
> 6 votes
Many people play this gambit.
Even some grandmasters.

At the highest level white's scoring chances are overwhelming. That says the gambit is unsound.

At lower levels black does a little better which says the players skill has a small bit to determine the outcome. But the gambit is still unsound and only has shock value in fast games to make it worth trying.

If you are doing well it is because your level is well below master and your opponents are likewise.

# Answer
> 1 votes
Isn't the problem with the Englund gambit that the mainline is basically busted unless you play the chessbrah queen sac? If black does not go for the trap line but plays nc6 then f6 or Qe7 d6, at least black has fast development, stockfish doesn't hate it. But it seems to me most people who play it want to go for the trap line with Qd2 qg4, but after Bd2 Nc3 from white black is lost if he does not sac the queen. I am interested in what Mr 1900 above is playing, as in my experience everyone in that rating range knows the refutation to the trap.

# Answer
> -1 votes
I am 1900+ on chess.com and 2100+ on lichess in blitz and bullet. I play the Englund gambit almost exclusively against white's 1. d4. It is 100% playable. Don't let anyone tell you otherwise.

---
Tags: opening, gambits
---


# Question
Title: Most recent "best in world" player who would be defeated by a CM
Of the chess players who could reasonably be considered the best in the world in at least one year in history, how far back would you have to go before one of them would lose to a 2020 Candidate Master (or FM or IM) in a classical game? How would historical figures such as Steinitz or McDonnell or Ruy López fare against the different ranks of titled players?

(Going back far enough, mileage on rules like castling or stalemate may vary. If you think it makes a difference which player's version of rules is used then give the answer both ways.)

# Answer
> 5 votes
McDonnell was never best in the world, and I doubt he would have been stronger than 2200 FIDE, a candidate master would be an even match. Out of the best players in the world, both Philidor and Labourdonnais would both be capable of being defeated by a CM, with regularity. It is difficult to compare strengths of the players from the past, because they would be possibly strong GM level in tactical calculation, but weak in openings and modern strategy. But I would estimate a regular 2200 FIDE CM could beat them on occasion

# Answer
> 1 votes
There has almost certainly never been a "world's best player" in the last few hundred years who would lose to some of the weak CMs around today (or even in 2020). You do not need a rating of 2200 to be a CM in today's world. You can be sub 1200 and "win" the title by finishing in the first 3 in a continental championship for under 8's.

To see a list of weak CMs go to the FIDE advanced ratings search page and search for CMs according to rating ascending. There are currently 7 players rated under 1200 in the list of CMs.

---
Tags: history, famous-players, titles
---


# Question
Title: How to make a computer play like a player?
Since computers have surpassed by now all humans, it should be very easy for it to emulate a strength of an weaker player. So the idea is:

* Supply a number of games
* The computer ajusts its options (Rating, Cowardice, Pawn Structure play, etc) to the player

EDIT:

For people who think the behavior of an engine cannot be changed to fit nearly a human:

http://wbec-ridderkerk.nl/html/UCIProtocol.html

You can set the options to be correct, but I was looking for an program to fit those options more or less.

Also ChessMaster has multiple characters you can play against, and I think they have some well defined traits : Passive, values bishops, etc. I think it is possible to find those preferences if you put enough games.

# Answer
> 14 votes
Firstly, you ***must understand*** how an engine plays chess, because if you don't you'll never understand why it's hard. Without going into too much technical details, an engine doesn't think. Even the most powerful chess engine in the world don't know how to play chess, they examine hundreds and thousands of positions. For each position, the engine uses some heuristic to derive a static evaluation for each position. The engine uses a technique known as alpha-beta to derive the overall optimal evaluation.

The key point to note that chess engine doesn't know how to play chess, it's simply a calculator. It doesn't know how to adjust itself from games, simply because it doesn't understand anything about chess.

It's **very easy** to tune down an engine's strength, but making it to play truly like a human is awfully hard. A chess engine never blunders, never forgets anything, never panic because you launch a king-side attack, never biased towards particular opponents etc. The way computer makes a move is simply very different to how you make a move.

I'll give you an example. Have you tried those weak playing levels in a chess app? Yes, you beat them easily, but that might be because they gave you a pawn for absolutely no reason and not under any pressure. Those engines were programmed to simulate blunders, but they couldn't simulate pressure, they just randomly blunder pawns and pieces. This is not a human play.

Programmers have tried to optimize an engine based on machine learning but with little success.

# Answer
> 4 votes
This has been done by Maia, a human-like neural network chess engine that's been trained to play like a human would.

> Note that each Maia plays at a level above the rating range it was trained on, for an interesting reason: Maia’s goal is to make the average move that players at its target level would make. Playing Maia 1100, for example, is more like playing a committee of 1100-rated players than playing a single 1100-rated player—they tend to average out their idiosyncratic mistakes (but Maia still makes a lot of human-like blunders!).

# Answer
> 2 votes
I couldn't make one play like a human. But it could play less than perfect. Have it select its move randomly from the top "n" moves, where lower value of "n" denote higher strength. n=1 would mean the computer would play the best move every time. An n of 2 would mean the machine would select randomly between the best 2 moves.

There would have to be exceptions to allow the machine to make immediate recaptures, etc., so it doesn't simply drop pieces.

I would venture that I, as a "B" player, could not beat Stockfish with n=10.

# Answer
> 1 votes
Simulating realistic human play of a given level by computer is an open problem. My impression (being an interested layperson) is that it is a problem that is attracting some amount of attention constantly, but that the amount of engineering effort that has gone into trying to solve it is orders of magnitude lower than that spent on designing strong chess programs. Hence I would not feel confident in predicting that a satisfactory solution is necessarily very hard, but I would confidently say that a solution cannot be produced as an afterthought to designing a strong chess program.

Both of the two main approaches to building a strong chess program (MCTS+neural networks for evaluation and search policy trained by reinforcement learning on the one hand, alpha-beta with various selective search heuristics and handcrafted evaluation functions on the other) do not try to simulate human chess cognition. There is therefore no expectation that these algorithms can be easily tweaked to produce human-like play.

# Answer
> 0 votes
I am not really sure I understand your question: are you asking how to do this, or pushing your ideas for others to evaluate? In any case, let me try.

First of all why do people say that computer can not play like a human. To support such claim there should be at least some studies which tells that a human can determine (with some accuracy) whether a game was played by the machine or not. (There was Kasparov accusing Deep Blue team that they used a human to help a machine, but no one proved anything). Something like a Turing test. I have not heard about such studies and I highly doubt that an above average chess player can accurately predict whether the game is played against a computer. For example, can you determine who is a machine here (or may it is just two humans):

```
[fen ""]
1. e4 e5 2. Nf3 Nc6 3. Nc3 f5 4. exf5 Bc5 5. Nxe5 Qe7 6. f4 Nf6 7. Bb5 Nd4 8. a4 a6 9. Be2 d6 10. Nc4 Bxf5 11. Ne3 O-O 12. Bc4+ Kh8 13. Ne2 Bxc2 14. Nxc2 Ng4 15. Ncxd4 Bxd4 16. Qb3 d5 17. Bxd5 Rae8 18. Bf3 Rxf4 19. Qxb7 Bc5 20. a5 Rff8 21. Qxa6 Qd7 22. h3 Ne5 23. Kd1 Nxf3 24. gxf3 Qd5 25. Kc2 Qxf3 26. Ng3 Qxg3 27. Rhf1 Qxh3 28. Rxf8+ Bxf8 29. Qb5 Re6 30. a6 Qh1 31. Ra4 Re1 32. Ra1 Re6 33. Ra4 Re1 34. Ra1 Re6 35. a7 Rc6+ 36. Kb3 Qf3+ 37. Ka2 Rc5 38. Qa4 Qd5+ 39. Kb1 Qh1 40. Ka2 Qd5+ 41. Kb1 Qh1 42. Ka2 Qd5+ 43. Kb1 1/2-1/2

```

Theoretically it is not hard to simulate game of a weaker opponent or an opponent with some preferences (we humans have preferences). In all artificial intelligence the move is determined based on a scoring function. So by modifying a scoring function you can achieve the game similar to what you want. For example if you want your machine to be more aggressive (attacking the opponent, sometimes even recklessly) you can modify it in such a way, that it will prefer lines where a lot of things can go wrong for the opponent. Even if with the best play you became a little bit worse.

Because you can modify a scoring function in any possible way, you can resemble the preferences of some humans playing solid/drawish lines, attacking, preferring knights over bishops, two rooks over a queen.

---
Tags: engines, style
---


# Question
Title: Other than Fairy-Max, is there a variant [fairy] chess engine that is compatible with XBoard?
Fairy-Max (which ships with the XBoard package) can play variant chess. Is there any other XBoard-compatible engine that also plays variant chess (and runs on Linux or \*BSD)?

# Answer
> 7 votes
The **XBoard Alien GUI** is reputedly better suited to playing chess variants than the standard XBoard is, but that's just an observation. There are many engines that play only a few variants.
Here's a list of engines (other than Fairy-Max) that have been noted as playing a large selection of variants and working with XBoard (Linux environment being implicit):

# Answer
> 0 votes
add Fairy Stockfish to that list... a recent development

---
Tags: engines, software, chess-variants, linux
---


title: A rook endgame from a classical book

text:
# Question
Title: A rook endgame from a classical book
From the game Kozul-Kurajica, Sarajevo 1998:

```
[FEN "2r3k1/5pp1/1p5p/3p4/8/P5P1/1P3PKP/4R3 w - - 0 0"]

```

In the above position; Stockfish 12 at a depth of 42 evaluates the position the position as +1.58 in Whites favour. With "Perfect Play" does the evaluation change significantly to give a definitive verdict.

Position from the book "Fundamental Chess Endings" - Müller & Lamprecht (2001) - Gambit Publications.

The game line was 1.Kf3 Kf8 (1...Rc2 2.Re2 wastes time, since the pawn ending is always lost) 2.Re3 Rc6 3.Rd3 Rd6 (3...Rc2 4.Rb3 loses) 4.Kf4 Re6 5.Kf3 (5.Rxd5 Re2 draws) Rd6 6.Ke3 Ke7 7.Kd4 Rf6 8.f3 Kd6 9.Re3 g5 10.a4 Re6? (decisive error by M/L; 10...h5 shall hold).

# Answer
So doing a reference cross check I managed to locate the game from which this position is derived from. The position occurs at the end of move 25.

```
[FEN ""]
[Event "Sarajevo Bosnia 28th"]
[Site "Sarajevo"]
[Date "1998.05.31"]
[White "Kozul, Zdenko"]
[Black "Kurajica, Bojan"]
[Result "1-0"]
[ECO "E00"]
[WhiteElo "2585"]
[BlackElo "2580"]

1. d4 Nf6 2. c4 e6 3. g3 Bb4+ 4. Nd2 c5 5. a3 Bxd2+ 6. Qxd2 cxd4 7. Nf3 d5 8. cxd5 exd5 9. Bg2 O-O 10. O-O Nc6 11. Nxd4 Re8 12. Nxc6 bxc6 13. Qc2 Ba6 14. Re1 Qb6 15. Bf4 Bc4 16. Rac1 h6 17. e4 Rac8 18. Be3 Qa6 19. exd5 Bxd5 20. Qc5 Bxg2 21. Kxg2 Nd5 22. Bd4 Rxe1 23. Rxe1 Qb6 24. Qxd5 cxd5 25. Bxb6 axb6 26. Kf3 Kf8 27. Re3 Rc6 28. Rd3 Rd6 29. Kf4 Re6 30. Kf3 Rd6 31. Ke3 Ke7 32. Kd4 Rf6 33. f3 Kd6 34. Re3 g5 35. a4 Re6 36. b4 Kc6 37. Rc3+ Kb7 38. Rc2 Rf6 39. Rf2 Rf5 40. b5 h5 41. Rf1 h4 42. Rf2 hxg3 43. hxg3 Kb8 44. g4 Rf4+ 45. Kxd5 Rxa4 46. Kc6 Ka7 47. Rc2 Ra3 48. f4 gxf4 49. Rc4 f3 50. Rf4 Rc3+ 51. Kd6 Kb8 52. Ke7 Kc7 53. g5 Rc5 54. Rxf7 f2 55. g6 Re5+ 56. Kf8+ Kd6 57. Rxf2 Rg5 58. Kf7 Kc5 59. Rf4 Kxb5 60. Kf6 Rxg6+ 61. Kxg6 Kc5 1-0

```

**Quick Visual Analysis:**

* Material is equal
* White has 2 pawn islands with a promotion threat on the A file in particular
* Black has 3 pawn islands.
* Whites Rook on the e file cuts the black king out of the game in the position , however white needs to activate the king and in doing so allows the black king to escape and join the play.

I would say given the position that white is winning but only slightly.

**Engine Analysis:**

Initial reports because the position had been reviewed multiple times.

* Deep Fritz Depth 22 = +0.48
* Houdini 4 x64 Depth 22 = +.041

I ran a StockFish 14 analysis on the position; which if you deem a engine as "Perfect Play" the position was drawn in most instances. However allowing it to run a bit longer; it appears that white can force the win.

```
[FEN "2r3k1/5pp1/1p5p/3p4/8/P5P1/1P3PKP/4R3 w - - 0 1"]
[Event "Sarajevo Bosnia 28th - Positional Analysis"]
[Site "Sarajevo"]
[Date "1998.05.31"]
[White "Stockfish 14"]
[Black "Stockfish 14"]
[Result "1-0"]
[ECO "E00"]

1. Re3 Kf8 2. Kf3 g5 3. h3 h5 4. Re5 g4+ 5. hxg4 hxg4+ 6. Kxg4 Rc2 7. b4 Rxf2 8. Rxd5 Ke7 9. Re5+ Kf8 10. Re1 Kg7 11. Re8 Rd2 12. Kf4 Rf2+ 13. Ke3 Rg2 14. Kf3 Rc2 15. Re3 Rc4 16. Ke2 b5 17. Kd3 f6 18. Kd2 Rc8 19. Rc3 Ra8 20. Kc2 f5 21. Kb3 Kf6 22. Rc6+ Ke5 23. Rc5+ Ke4 24. Rxb5 Rg8 25. Ka4 Rxg3 26. Rb8 f4 27. Re8+ Kd3 28. Rf8 f3 29. b5 Ke2 30. b6 f2 31. b7 f1=Q 32. Rxf1 Rg4+ 33. Kb3 Rg3+ 34. Ka2 Rg8 35. Rb1 Rb8 36. Rb5 Kd3 37. a4 Kc4 38. Rb3 Kc5 39. a5 Kc4 40. a6 Rf8 41. b8=Q Rf2+ 42. Ka3 Rf6 43. Rb4+ Kd5 44. Qb5+ Ke6 45. Re4+ Kf7 46. Qe8+ Kg7 47. Rg4+ Kh7 48. Qg8+ Kh6 49. Rh4#

```

The engine at this point keeps going around in a circle and will eventually reach draw via threefold repetition.
> 1 votes

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Tags: analysis
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