# Question
Title: Chess960 - can Black profit by being allowed to choose a custom setup?
In Chess960, the White position is mirrored. In some positions, White enjoys a larger first-move advantage than in standard chess. Could we make Chess960 fairer by allowing Black to choose his setup (still following Chess960 rules for the starting position) based on White's?

If so, why isn't this done in contemporary Chess960 tournaments?

# Answer
I did the analysis! Big thanks to @Allure for sharing the data! As I mentioned in the comments, how much Black can profit, will depend on White's setup. In the worst existing position for Black as found in the answer from @Allure, Black could rearrange the pieces and have multiple setups where White has no advantage, e.g. this one:

```
   [FEN "nbbqrnkr/pppppppp/8/8/8/8/PPPPPPPP/BQRNNKRB w KQkq - 0 1"]

```

# **Summary of results regarding DFRC fairness:**

If White's position is randomly assigned and Black is allowed to adapt his battle line-up to counter White's attack, **Black is almost always better, even though White gets the first move advantage.** The markedness was very surprising, see the **centipawn evaluation summary statistics** for yourself:

* **mean**: -109
* **min** : -243
* **25%** : -139
* **50%** : -110
* **75%** : -77
* **max** : 23

On average, Black can get an advantage of -1. If White is fortunate, he can get one of two positions, where he has a guaranteed first-move advantage comparable to standard chess, no matter Black's setup (about 20 centipawns). In the worst case, White is losing from the start. The harmonious-looking standard chess setup isn't very robust for White. Black has multiple setups that give him an advantage of about -100 centipawns, e.g. this one:

```
   [FEN "bbnrqkrn/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]

```

For seeing more examples and the best and worst setups, check the analysis.

**The best setup for White**, i.e. most robust w.r.t. Black's possibilities is the following:

```
 [FEN "bbrqnnkr/pppppppp/8/8/8/8/PPPPPPPP/BQRBNNKR w KQkq - 0 1"]

```

The only other setup where White has a guaranteed first-move advantage is this very setup, mirrored. There seems to be something particularly good about this piece coordination for White (even though the castling would differ). If Black isn't careful with his setup, he can quickly find himself losing from the start (337 centipawns). Interestingly, the engine likes 1. a4 as an opening (more on best opening moves later).

**I further investigated, how large the advantage for White would be if both sides can influence the setups:**

1. White advantage when Black decides on White's setup first and White decides on Black's setup: White always has a sizeable advantage
2. White advantage when White decides on Black's setup first and Black decides on Whites's setup: Black almost always has an advantage (the first move advantage helps White to not always be worse)

Therefore, it is beneficial to have the last word, even if the opponent can try to mess up your own position however they like. There are no setups that are so bad that the opponent couldn't find a setup for you that is pretty bad against what you chose for them.

Furthermore, I analyzed the **importance of undefended pawns in the starting position** on its fairness. At first glance, it doesn't seem to have a large impact on the evaluations, even if only one side had weaknesses. If that was the case, however, it had an impact on the best opening moves for White.

**Best opening moves for White**

> Seize the centah! (*IM Andras Toth*)

It's comforting to see, that the opening principles still generally apply. The most frequent best moves:

**Chess960** : number of occurrences (number of occurrences if neither side has weaknesses):

* **e4** : 168 (89)
* **d4** : 149 (77)
* **f4** : 132 (43)
* **c4** : 121 (48)

**Double Fischer Random** : number of occurrences (number of occurrences if neither side has weaknesses)

* **e4** : 117246 (23491)
* **f4** : 115029 (16425)
* **d4** : 102330 (20973)
* **b3** : 92310 (9288)
* **g3** : 90390 (8734)
* **c4** : 88084 (13381)

**Double Fischer Random** : number of occurrences, only Black has weaknesses

* **e4** : 32346
* **f4** : 27672
* **d4** : 27415
* **c4** : 22421

**Double Fischer Random**: number of occurrences, only White has weaknesses

* **f4** : 27931
* **b4** : 26486
* **g3** : 25791
* **e4** : 24821
* **d4** : 22836
* **c4** : 20522

**e4 is generally the best first move for White** (just like in regular chess :P ). Most often, the best first move is to control the center with a pawn (at least from the side). The pawn that is the best one to move depends on its impact on piece development. If neither side has weaknesses, the ranking of best first moves is e4, d4, f4, and c4. If the own position has weaknesses, it seems we need to be more careful in the opening, with modest moves such as b3 and g3 being good (probably activating a bishop or queen) and controlling the center with pieces.

**Limitations:** All of the analysis is based on the data provided by TCEC with engine evaluations of depth 20. The evaluations can change with increasing depth. Some of the evaluations differ from those on my local machine. The evaluations are also dependent on engine configuration. The general findings should however be valid.
> 5 votes

# Answer
You're referring to what is known as double FRC - the starting position is not mirrored. While there are no FRC positions that favor Black, there *are* DFRC positions that favor Black.

DFRC was played in some TCEC bonuses. Here's the data with all the evals, and this is the position that favors Black the most, with an opening eval of -2.43 (!!).

```
[FEN "nbbqrnkr/pppppppp/8/8/8/8/PPPPPPPP/RQNKBBRN w KQkq - 0 1"]

```

If you're curious here is the position that favors White the most, with an opening eval of +3.59.

```
[FEN "qrkrbbnn/pppppppp/8/8/8/8/PPPPPPPP/BQRNNKRB w KQkq - 0 1"]

```

I leave it to players better than me to explain why these positions are so decisive.

As for why there are no DFRC tournaments - I can only speculate, but the fact that the opening evals are so decisive does not bode well for the inferior side. You could be dead lost before you make a move!
> 8 votes

---
Tags: theory, chess960
---


title: What is the color of a forfeit?

text:
# Question
Title: What is the color of a forfeit?
Again, wonders of Swiss.

Before the last round, I had bwbwbbwf. My opponent had bwbwbwbw. The f wasn't a colorless bye (I'd give up chess then :-) but a forfeit after pairings were out (due to sudden sickness of my R8 opponent). Is a forfeit unconditionally as colorless as a bye? (In that case, the colors are obvious, since my preference is strong w and my R9 opponent's weak b.) I read §C042D5 as affirmative of that assertion, am I correct?

# Answer
> 8 votes
FIDE document C.04.2 General handling rules for Swiss Tournaments gives the answer:

> Only played games count in situations where the colour sequence is meaningful. So, for instance, a player with a colour history of BWB=W (i.e. no valid game in round-4) will be treated as if his colour history was =BWBW. WB=WB will count as =WBWB, BWW=B=W as ==BWWBW and so on.

Hence your "bwbwbbwf" converts to "bwbwbbw=" in the notation of the document and that will be treated as if your colour history was "=bwbwbbw". So you will have a strong preference for white, as you say.

---
Tags: swiss-pairing
---


title: What is the FIDE Arbiter's exam like?

text:
# Question
Title: What is the FIDE Arbiter's exam like?
According to the FIDE Handbook (B.06.1.3.7), one of the requirements to become a FIDE Arbiter is:

> Attendance of one (1) FIDE Arbiters’ Seminar and successfully passing (at least 80%) an examination set up by the Arbiters’ Commission.

**What's the exam like?**

To be clear, I'm not asking anyone to give me the answers or help me cheat, just asking for a brief overview of what kinds of questions are on the exam.

* Is the exam mostly multiple-choice questions on the rules of chess (e.g. "Which of the following moves is legal?")?
* Is it mostly essay questions on tough professional judgments (e.g. "What would you do if a player complains that their opponent has poor body odor but you determine that the odor is caused by a bona-fide medical condition that the opponent cannot reasonably afford to get treated?")?
* Is the exam a practical demonstration of arbitration skills performed using actors cast in the roles of players?

# Answer
> is the exam mostly multiple-choice questions

Certainly not. Multiple choice questions were an invention when education became a business with "customers" and accreditation had to be made easier.

The most important section in the FIDE Laws of Chesss is the Preface where it says this:

> The Laws of Chess cannot cover all possible situations that may arise during a game, nor can they regulate all administrative questions. Where cases are not precisely regulated by an Article of the Laws, it should be possible to reach a correct decision by studying analogous situations which are regulated in the Laws. **The Laws assume that arbiters have the necessary competence, sound judgement and absolute objectivity. Too detailed a rule might deprive the arbiter of his freedom of judgement and thus prevent him from finding a solution to a problem dictated by fairness, logic and special factors**

To test if candidates have "*the necessary competence, sound judgement and absolute objectivity*" to be good arbiters the questions are mostly open-ended questions where, as well as giving a laws-based answer, candidates have to explain what else they would do and say and explain these actions.

Candidates who fail to do this while at the same time as giving answers which are 100% correct with respect to the Laws will fail.

Just to emphasise this point. The exam is open book. You can take your copy of the FIDE Laws in with you and consult them during the exam.

Note: I sat and passed the exam in December 2011.
> 18 votes

# Answer
In *addition* to Brian's answer, I'd like to point out that different federations may place the emphasis on different skills. I took only the national arbiter exam (rules, more rules...and some rules too) but know the curriculum of the German FIDE arbiter seminar. The main theme definitely was Swiss pairing and title regulations.

P.S. I don't recall multiple choice questions in the German national exam either. Although for pure rule questions they wouldn't do harm.

P.P.S. German passing scores are 80% on NA and 90% on FA...and since in my NA seminar almost everybody scored over 90%, all below 95% or so had to take an additional oral exam to pass.
> 6 votes

---
Tags: fide, arbiters
---


title: How many centipawns guarantee winning?

text:
# Question
Title: How many centipawns guarantee winning?
Since the question in this form is somewhat ill-defined, I elaborate on it so it can be solved by experiment:

What is the maximum centipawn value you can come up with so that the weaker side holds a draw?

Assume two very strong deterministic (i.e., you only need one game) computers play out a position which is very bad (with value c centipawns) for one side, but the weaker side still draws. Say, two Leela copies. (Fortresses would be the first thing I'd try. But they neither may be solvable by tablebases nor a draw by 50 move/3 repetitions inside the horizon, otherwise it's an immediate 0.0!)

P.S. For a "normal" position I expect a guaranteed win somewhere in the evaluation range +2 to +3.

# Answer
> 5 votes
This position looks familiar, doesn't it? ;)

As you can check on lichess, the evaluation is nearly +8, and yet the position is as dead as it can be...

```
[Title "Diagram from Black's perspective"]
[FEN "kR6/p1p1p1p1/P1P1P1P1/p1p1p1p1/8/8/PKP1P1P1/8 b - - 0 1"]
[startlfipped ""]

```

There are countless such examples, check this and this.

If you want to know the *practical* winning centipawn threshold (arising in realistic games), my guess would be something near 1.5.

---
Tags: computer-chess, evaluation
---


# Question
Title: Export all of my played games from chess.com
How can I export all my games played on chess.com?

For example to import to another program for analysis.

Exporting from the chess.com games list only shows the most recent 50 games.

# Answer
1. OpeningTree.com allows you to export all games played as White or Black by username.
2. Python wrapper for chess.com API by Artur Saradzhyan (I have not tested this.)
3. Manually export games from the chess.com game list, 50 at a time by date range (may require trivial deduplication). Supports chess clock info.
> 4 votes

# Answer
@qwr’s answer to their own question mentions a “Python wrapper for chess.com API,” but I think it’s worthwhile answering with the API itself, because it’s very accessible without any need to know/use Python. Hence…

Chess.com has, a fairly recently provided, Published Data API. See announcement by Ben Curtis, on May 10, 2022: “Published-Data API”:

> The PubAPI is a read-only REST API that responds with JSON-LD data. Our goal is to re-package all currently public data from the website and make it available via the PubAPI. "Public Data" is information available to people who are not logged in, such as player data, game data, and club/tournament information. This excludes private information that is restricted to the logged in user, such as game chat and conditional moves.

The key with using a REST API is to construct the appropriate URL that represents your query. (See Zell Liew, “Understanding And Using REST APIs, Smashing Magazine, May 20, 2021, for the most-accessible intro I know about getting information from a REST API.)

For example, to find out some basic information about Hikaru, specifically his “user profile,” put the following URL in your browser’s address bar:

```
https://api.chess.com/pub/player/hikaru

```

Your browser will return with:

```

avatar  "https://images.chesscomf…0x200o.f323efa57fd0.jpeg"
player_id   15448422
@id "https://api.chess.com/pub/player/hikaru"
url "https://www.chess.com/member/Hikaru"
name    "Hikaru Nakamura"
username    "hikaru"
title   "GM"
followers   983906
country "https://api.chess.com/pub/country/US"
location    "Sunrise, Florida"
last_online 1662743764
joined  1389043258
status  "premium"
is_streamer true
twitch_url  "https://twitch.tv/gmhikaru"
verified    true

```

For basic statistics about a player (ratings, win/loss, and other stats about a player's game play, tactics, lessons and Puzzle Rush score), tack on “/stats” to the previous URL:

```
https://api.chess.com/pub/player/hikaru/stats

```

This produces a long-ish regurgitation of statistics, for example, that Hikaru’s last bullet rating was 3352:

```
. . .

chess_bullet
last
rating  3352
date    1661276020
rd  41
best
rating  3570
date    1605136047
game    "https://www.chess.com/game/live/5710095242"
record
win 10136
loss    1376

. . .

```

Most directly on point to your question, you can get the PGN for all games a given player (i.e., *you*) played in a month. For Hikaru, for April 2022, the URL would be:

```
https://api.chess.com/pub/player/hikaru/games/2022/04/pgn

```

and your browser will download a multi-game PGN file.

AFAICT, you can download a player’s game for a particular month, but not for any broader period.

Since the URLs are very simple, it would be pretty easy to construct several year’s worth of URLs with a text editor and copy/pasting to change the years and months.
> 2 votes

# Answer
Use my API to get all games.

https://github.com/ChameleonRed/cw\_download\_chess\_com\_games

It is very simple.
> 0 votes

---
Tags: software, pgn, chess.com, download-games
---


# Question
Title: Why did Garry Kasparov not play under the flag of Azerbaijan in his comeback tournament in the summer of 2017?
Garry Kasparov was born in 1963 in Baku, Azerbaijan, at the time part of the USSR, Soviet Union.

According to the news he has also acquired Croatian citizenship.

In his comeback tournament in the summer of 2017 he still used the Russian flag. However I did see a Croatian flag together with the Russian one on the poster behind him at the signature sessions between the matches.

But why did Garry Kasparov not play under the flag of Azerbaijan?

# Answer
> 36 votes
> But why did Garry Kasparov not play under the flag of Azerbaijan?

Because his FIDE registration is with Russia.

If he wants to change his registration to Azerbaijan then the following also have to happen -

1) He has to have a valid claim like residency, nationality or birth, so birth would do.

2) Azerbaijan chess federation have to agree.

3) An administration fee has to be paid to FIDE and possibly a "transfer" fee also. Because Kasparov is a highly rated GM this would be very large. I think when Caruana transferred from Italy to US it was more than $50,000.

The section of the FIDE handbook which describes the rules is here.

# Answer
> 3 votes
He has an RF (Russian Federation) citizenship or, at least, he did at some point. In fact, he was the head of a minor party in RF which even held a few seats in the RF parliament at some point.

# Answer
> 1 votes
He did not play under the flag of Azerbaijan in his comeback tournament because he, and many of his relatives fled Baku in 1990, fearing for their lives... Pogroms by lynch mobs of Azeri nationalists. https://www.youtube.com/watch?v=RqXubG9MV10

---
Tags: kasparov
---


# Question
Title: What is the point of a5 in Sveshnikov Nd5 variation?
I am currently learning Sicilian Svenshnikov. Today, I came across a new line with Nd5 variation. First, we move a4 to kick the white knight and then play a5. I couldn't quite understand the point of this move as it gives back white the b5 square for its knight again. So what was the point of playing a5?

Here's the position for it:

```
[FEN ""]
[Startply "27"]

1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 e5 6. Ndb5 d6 7. Nd5 Nxd5 8. exd5 Nb8 9. a4 Be7 10. Be2 O-O 11. O-O Nd7 12. Bd2 a6 13. Na3 a5

```

# Answer
> 5 votes
> So what was the point of playing a5?

It is a prophylactic move. It takes the square away from White who was planning to play a5 and take control of the key b6 square in Black's position. Sure, Black could try playing b6 but after the exchange of pawns on b6 black would be left with a weak isolated a pawn.

---
Tags: opening, learning, sicilian-defense
---


# Question
Title: When is it okay to break a pin using kingside pawns?
In the following position, Stockfish recommends h3 followed by g4. I can understand feeling okay to move your kingside pawns in a closed position or an endgame, but I don't know if this position would qualify as either.

What about this position makes one feel comfortable to move the kingside pawns? Is it because black's knight is far from the kingside and white's knight is by the king? Other considerations?

```
[fen "q4r1k/1n2bppp/2pp4/4p3/1PB1P1b1/3P1N2/3B1PPP/3Q1RK1 w - - 0 1"]

```

# Answer
> 7 votes
> What about this position makes one feel comfortable to move the kingside pawns?

With so few black pieces on the kingside (really just two bishops unless somehow the rook can get involved) there is no danger. If it were black to move then a really good move would be f5 trying to break up the white center and open a file for the rook. But once white has time to play h3 and g4 this break becomes impossible. So, the move h3 has two purposes.

# Answer
> 3 votes
In any position, you should evaluate the pros and cons of each reasonable candidate move.

The cons of 1.h3 2.g4, as you correctly identified, is a potential weakening of your king. This is a valid concern. However, if you look at it more deeply, is there really a threat to your king safety? Yes, moving the pawns is conceptually dangerous, but it is important to consider the concrete details of the position: all of your pieces are more or less on the kingside, protecting your king, so there is almost no way that he will be able to checkmate you despite the weakening of your king. Even if the black queen teleports to g8 and knight teleports to g6, and black's pawn teleports to f5 as well, you are still not under any kind of devastating attack. It is simply inconceivable for any attack to work out when all your pieces are in good position for defence!

The pros are significant. Firstly, you force black to make a decision that allows you to unpin your knight and make your pieces slightly less awkward. (E.g. if instead 1.Qb3, you have to worry about 1...Bxf3 possibly giving you an endgame liability in doubled pawns; though not that it necessarily is a big problem in this exact position.) Secondly, if 1.h3 Bxf3, you gain the bishop pair, which is good. Even if 1.h3 Bh5 2.g4 Bg6, his bishop is entombed biting into your concrete pawn wall on d3-e4 and absolutely depressed. Black now has to spend time trying to play d5 to reactivate the bishop, which gives you time to do other things to improve your position and puts the onus on Black to find a plan to not have a worse position. Not to mention, the g6 bishop blocks the g7 pawn (black would like to play ...g6, f5 to break, but this is physically impossible). Black's position would be depressing while you have all sorts of ideas on the queenside like eventually getting the rook to a1 or c1 attacking the c6 weakness, or pushing the b pawn to promotion depending on Black's response.

On balance, the pros outweigh the cons, so 1.h3 2.g4 is a good plan.

---
Tags: analysis, strategy
---


# Question
Title: Are endgame tablebases included with Stockfish?
I just downloaded Stockfish as a .exe file for use with SCID vs PC. Are tablebases included with the executable? If not, how can I make Stockfish use them while analysing a game with SCID vs PC?

I understand that 6-7 piece tablebases are very large, but how about 5-piece?

# Answer
Just turned my comments above into an answer:

Nope, they aren't included by default. You'd have to download the tablebases you want and then get Stockfish to use them. I haven't done this myself, but this seems to be a good guide: https://www.reddit.com/r/chess/comments/7477uh/how\_to\_freely\_install\_a\_tablebase\_for\_stockfish/

As for the size of 5-piece tablebases, those shouldn't be a problem for memory. 6-piece is over 100GB though.
> 3 votes

---
Tags: stockfish, tablebases, scid
---


# Question
Title: What is new in the fifth edition of Dvoretsky's Endgame Manual?
It seems the only change between the fourth and fifth edition (after the author's passing) was a change in color. This surely can't be enough for a new edition, so I wonder what changes to the content were made?

> German grandmaster Karsten Müller, widely recognized as one of the best endgame theoreticians in the world today, has carefully updated the fifth edition with the help of American grandmaster Alex Fishbein. The incredible instructional value of the exercises has been preserved, and the blue text used in the first four editions has been replaced with text with a light grey background.

# Answer
1. The fifth edition (DEM5) has 440 pages, 16 more than the fourth edition. The book has been completely reformatted, and the diagrams have all been re-set.
2. There is a new foreword by former world champion Vladimir Kramnik and a new introduction by Karsten Müller.
3. The revision has been done by German GM Karsten Müller. With the passing of Mark Dvoretsky, Karsten has been generally recognized as the premier endgame analyst and theoretician in the world today. American GM Alex Fishbein assisted Karsten.
4. There have been new developments in several areas of theory (e.g., Bishop Endgames), and these were added.
5. Karsten and Alex have gone through the existing text of DEM4 very carefully, making minor changes and corrections throughout. New diagrams have been added, some have been removed. The complex indexing systems put in place by Dvoretsky have been modified accordingly.
6. The blue text in previous editions has been replaced by normal text highlighted with a light gray background.
> 5 votes

---
Tags: endgame, books
---


title: Longest sequence of unique series moves

text:
# Question
Title: Longest sequence of unique series moves
Clearly a spawnoff of the preceding question, but far easier to analyze, and maybe helping a bit to solve that one too.

Take the starting position, remove all black pieces to simplify and now make only white moves. Again, if you can reach the position in fewer moves or the same number of moves in a different way, the game stops and your score is the number of moves.

Example: 1.a3. You now only have 2.Ra2 and then you are stuck. I would be impressed if anyone even reaches 10 moves.

Jacobi can help with this.

# Answer
> 8 votes
**Addendum 10/29/2022:** See @Evargalo's answer below, in which they have concocted a verified, again by Jacobi, 30 move sequence.

Silly Hauke, did you not check the PDB database: "k='series' and stip='bp'"? :-)

I found a seriesmover that can be withered down to 24 moves to fit the bill.

#1

```
[Title "François Labelle, Phénix 279-280, Series Proof Game In 31.0 Moves, Abridged To 24.0"]
[FEN "8/8/8/8/8/8/PPPPPPPP/RNBQKBNR w KQ - 0 1"]

1. Nc3 null 2. Nd5 null 3. c3 null 4. Qa4 null 5. Qa6 null 6. a4 null 7. a5 null 8. Ra4 null 9. Rg4 null 10. Rg5 null 11. g4 null 12. Bg2 null 13. Be4 null 14. Bb1 null 15. d3 null 16. Bf4 null 17. e3 null 18. Ne2 null 19. Rg1 null 20. Rg3 null 21. Rh3 null 22. Rh6 null 23. h3 null 24. Bh2

```

I computer verified this with Jacobi, as linked above by @Hauke Reddmann, using this string:

EnglishN forsyth 8/8/8/8/8/8/PPPPPPPP/RNBQKBNR stipulation ser-a=\>b24 forsyth 8/8/Q6R/P2N2R1/6P1/2PPP2P/1P2NP1B/1B2K3

It can be extended to 29 with a different move order, starting at move 24 .@Evargalo I ran Jacobi with this code: EnglishN forsyth 8/8/8/8/8/8/PPPPPPPP/RNBQKBNR stipulation ser-a=\>b29.0 forsyth 8/8/Q6R/P2N2R1/5PPK/2PPP1NP/1P5B/1B6

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

1. Nc3 null 2. Nd5 null 3. c3 null 4. Qa4 null 5. Qa6 null 6. a4 null 7. a5 null 8. Ra4 null 9. Rg4 null 10. Rg5 null 11. g4 null 12. Bg2 null 13. Be4 null 14. Bb1 null 15. d3 null 16. Bf4 null 17. e3 null 18. Ne2 null 19. Rg1 null 20. Rg3 null 21. Rh3 null 22. Rh6 null 23. h3 null 24. Bh2 null 25. f4 null 26. Kf2 null 27. Kg3 null 28. Kh4 null 29. Ng3

```

# Answer
> 6 votes
My current best try is **33 moves**.

*(a previous attempt in 34 moves has been demolished by my friend Yosha Iglesias)*

The most promising idea I have found is to promote a pawn into a bishop and bring it back to the 2d or 1st rank.

The record (**33 moves**) is reached with **the b-pawn** :

*Series shortest proof game - 33, White pieces only* (C?) :

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

1. b4 null 2. b5 null 3. b6 null 4. b7 null 5. b8=B null 6. Be5 null 7. Beb2 null 8. c3 null 9. Qa4 null 10. Qa6 null 11. a4 null 12. a5 null 13. Ra4 null 14. Rf4 null 15. Rf6 null 16. f4 null 17. Kf2 null 18. Kg3 null 19. Kh4 null 20. g3 null 21. Bh3 null 22. Be6 null 23. h3 null 24. Rh2 null 25. Rf2 null 26. Rf3 null 27. Rd3 null 28. Rd8 null 29. d3 null 30. Nd2 null 31. Nb3 null 32. Bd2 null 33. Nc1

```

The longest version that has been checked with Jacobi (in 21217 seconds!) is **32 moves** long:

*Series shortest proof game - 32, White pieces only* (C+) :

1.b4 2.b5 3.b6 4.b7 5.b8=B 6.Be5 7.Beb2 8.c3 9.Qa4 10.Qa7 11.a4 12.a5 13.Ra4 14.Rf4 15.Rf5 16.f4 17.Kf2 18.Kg3 19.Kh4 20.g3 21.Bh3 22.Bg4 23.h3 24.Rh2 25.Rf2 26.Rf3 27.Rd3 28.Rdd5 29.d4 30.Sd2 31.Sf1 32.Bd2

---

Previous record was 30 moves with **the a-pawn**, also verified by engine thanks to Rewan Demontay.

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

1. a4 null 2.a5 null 3.a6 null 4.a7 null 5.a8=B null 6.Bd5 null 7.Ba2 null 8.b3 null 9.Bb2 null 10.Bf6 null 11.Nc3 null 12.Rb1 null 13.Rb2 null 14.Qa1 null 15.Bb1 null 16.Qa4 null 17.Qh4 null 18.g4 null 19.Bg2 null 20.Bb7 null 21.Nf3 null 22.O-O null 23.Kg2 null 24.Kg3 null 25.Kf4 null 26.Ke5 null 27.Kd6 null 28.Kc7 null 29.Kb8 null 30.Ka8

```

The a-pawn is so strong that we can even get to 25 moves by playing only the queenside:

*Series shortest proof game, White pieces only*, **25 moves** :

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

1. a4 null 2.a5 null 3.a6 null 4.a7 null 5.a8=B null 6.Bd5 null 7.Ra8 null 8.Ba2 null 9.b3 null 10.Ba3 null 11.Be7 null 12.Na3 null 13.Qa1 null 14.Kd1 null 15.Kc1 null 16.Kb2 null 17.Kc3 null 18.Kd4 null 19.Ke5 null 20.Kf6 null 21.Kg7 null 22.Kh8 null 23.Qg7 null 24.Bf6 null 25.Qb7

```

With a **bishop pawn** (c- or f-), there are many ways to reach **28 moves** :

1.f4 2.f5 3.f6 4.f7 5.f8=B 6.Bc5 7.Bf2 8.e3 9.Ke2 10.Kd3 11.Kc4 12.Kb5 13.Ka6 14.Bb5 15.Se2 16.Rf1 17.Bg1 18.Rf4 19.Rb4 20.c4 21.Qa4 22.b3 23.Bb2 24.Be5 25.Sbc3 26.Re1 27.Sc1 28.Re2 (C+)

1.f4 2.f5 3.f6 4.f7 5.f8=B 6.Bc5 7.Bf2 8.e3 9.Bd3 10.Se2 11.Rf1 12.Bg1 13.Rf4 14.Ra4 15.c4 16.Qb3 17.Qb8 18.b3 19.Bb2 20.Bh8 21.Sbc3 22.O-O-O 23.Bb1 24.Kc2 25.Kd3 26.Kd4 27.d3 28.Rd2 (C+)

1.c4 2.c5 3.c6 4.c7 5.c8=B 6.Bf5 7.Bc2 8.d3 9.Be3 10.Sd2 11.Rc1 12.Bb1 13.Rc4 14.Rg4 15.f4 16.Kf2 17.Kg3 18.Kh4 19.Kh5 20.h4 21.Rh3 22.Rhg3 23.Sh3 24.Bg1 25.e3 26.Be2 27.Bf3 28.Qe2 (C+)

Here is **28 moves** with **the g-pawn** :

1.g4 2.g5 3.g6 4.g7 5.g8=B 6.Bd5 7.Bdg2 8.Sf3 9.Rg1 10.Bh1 11.Rg4 12.Rc4 13.d4 14.Kd2 15.Kc3 16.Kb4 17.c3 18.Qa4 19.Qa8 20.a4 21.a5 22.a6 23.a7 24.Ra6 25.Ka5 26.b4 27.Bb2 28.Ba1 (C+)

With **the h-pawn**, I also get **28 moves** :

1.h4 2.h5 3.h6 4.h7 5.h8=B 6.Be5 7.Rh8 8.Bh2 9.f4 10.Kf2 11.Kg3 12.Kh4 13.g3 14.Bh3 15.Be6 16.Sh3 17.Qg1 18.Qa7 19.d4 20.Be3 21.Sd2 22.Rf1 23.Rf3 24.Bf2 25.Rb3 26.Rb5 27.b4 28.Sb3 (C+)

Alternative finish: 1.h4 2.h5 3.h6 4.h7 5.h8=B 6.Be5 7.Rh8 8.Bh2 9.f4 10.Kf2 11.Kg3 12.Kh4 13.g3 14.Bg2 15.Be4 16.Sf3 17.Qg1 18.Qc5 19.d4 20.Bd2 21.Bb4 22.Sc3 23.Rd1 24.Rd3 25.Sd1 26.Ra3 27.Ra4 28.Ba3 (C+)

Finally, the **central pawns** are not very promising unless I miss some smart trick...

---

Without pawn promotion, this construction is in **22 moves** :

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

1. Nc3 null 2.Ne4 null 3.c3 null 4.Qa4 null 5.Qa8 null 6.a4 null 7.Ra3 null 8.Rb3 null 9.Rb6 null 10.b3 null 11.Ba3 null 12.Be7 null 13.Bh4 null 14.Ng5 null 15.e4 null 16.Ke2 null 17.Kd3 null 18.Kc4 null 19.Kb5 null 20.Ka6 null 21.Ka7 null 22.Ba6

```

---

*Other ideas :*

1.b4 2.b5 3.b6 4.b7 5.b8=B 6.Be5 7.Beb2 8.c3 9.Qa4 10.Qa6 11.a4 12.a5 13.Ra4 14.Rh4 15.Rh5 16.h4 17.Rh3 18.Rf3 19.g3 20.Bh3 21.Bf5 22.Bc2 23.d3 24.Kd2 25.Ke3 26.Kd4 27.Kc5 28.Kb6 29.Ka7 (C+)

1.b4 2.b5 3.b6 4.b7 5.b8=B 6.Be5 7.Beb2 8.c3 9.Qa4 10.Qa7 11.a4 12.a5 13.Ra4 14.Rg4 15.Rg5 16.g4 17.Bg2 18.Bb7 19.Sf3 20.O-O 21.Kg2 22.Kg3 23.Kf4 24.Ke5 25.Kd6 26.Kc7 27.Kb8 (C+)

1.f4 2.f5 3.f6 4.f7 5.f8=B 6.Bc5 7.Bf2 8.e3 9.Ke2 10.Kd3 11.Kc4 12.Kb5 13.Ka6 14.Bb5 15.Se2 16.Rf1 17.Bg1 18.Rf4 19.Ra4 20.b4 21.Bb2 22.Bf6 23.Sbc3 24.Rb1 25.Rb3 26.Qb1 27.Sc1 (C+)

1.c4 2.c5 3.c6 4.c7 5.c8=B 6.Bf5 7.Bc2 8.d3 9.Kd2 10.Ke3 11.Kf4 12.Kg5 13.Kh6 14.Bg5 15.Sd2 16.Rc1 17.Bb1 18.Rc4 19.Rh4 20.g4 21.Bg2 22.Bc6 23.Sgf3 24.Rg1 25.Rg3 26.Qg1 27.Sf1 (C+)

1.f4 2.f5 3.f6 4.f7 5.f8=B 6.Bc5 7.Bf2 8.e3 9.Bd3 10.Se2 11.Rf1 12.Bg1 13.Rf4 14.Rb4 15.c4 16.Qa4 17.Qa7 18.a4 19.Ra3 20.Rab3 21.Sa3 22.Bb1 23.d3 24.Kd2 25.Kc3 26.Kd4 (C+)

1.a4 2.a5 3.a6 4.a7 5.a8=B 6.Bf3 7.e4 8.Se2 9.Sec3 10.Sa4 11.c3 12.Qb3 13.Qb8 14.b4 15.b5 16.b6 17.Bb5 18.O-O 19.Re1 20.Re3 21.Bfe2 22.Rh3 23.Rh4 24.h3 25.Kh2= (C+)

1.h4 2.h5 3.h6 4.h7 5.h8=B 6.Bc3 7.d4 8.Bf4 9.e3 10.Ke2 11.Kf3 12.Kg4 13.Kh5 14.Qg4 15.Be2 16.Bf3 17.Se2 18.Rd1 19.Be1 20.Sd2 21.Rac1= (C+)

1.h4 2.h5 3.h6 4.h7 5.h8=B 6.Bc3 7.d4 8.Sd2 9.Sdf3 10.Sh4 11.f3 12.Kf2 13.Kg3 14.Kg4 15.Kh5 16.g4 17.Bh3 18.Qf1 19.Be1 20.c3= (C+)

1.h4 2.h5 3.h6 4.h7 5.h8=B 6.Bc3 7.Bb4 8.c3 9.Qa4 10.Qa8 11.a4 12.a5 13.a6 14.Ra5 15.Rah5 16.R5h2 17.Sh3 18.Rg1 19.Rhh1= (C+)

1.h4 2.h5 3.Rh4 4.Ra4 5.b4 6.Bb2 7.Be5 8.Bh2 9.g3 10.Bh3 11.Kf1 12.Kg2 13.Kf3 14.Ke4 15.Nf3 (simply 15.Kd5 16.Kc6 17.Kb7 18.Ka8 is also 18 moves) 16.Qh1 17.Bg1 18.Qh2

1.a4 2.a5 3.Ra4 4.Rg4 5.g4 6.Bg2 7.Bd5 8.Ba2 9.b3 10.Ba3 11.Bf8 12.Na3 13.Qa1 14.Kd1 15.Kc1 16.Kb2 17.Qc1 18.Bb1 19.Ka2

1.a4 2.a5 3.Ra4 4.Rg4 5.f4 6.Kf2 7.Kg3 8.Kh4 9.Kh5 10.h4 11.Rh3 12.Rd3 13.g3 14.Bg2 15.Ba8 16.Nf3 17.Qh1 18.Ne1 19.Qb7 and maybe 20.Ng2

# Answer
> 2 votes
Here is an attempt of 8 moves:

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

1. h4 null 2. h5 null 3. h6 null 4. h7 null 5. h8=N null 6. Nf7 null 7. Nd6 null 8. Nb5

```

# Answer
> 1 votes
I can manage 10 moves.

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

1. Nf3 null 2. Nd4 null 3. f3 null 4. Kf2 null 5. Ke3 null 6. Ke4 null 7. Kd5 null 8. Kc6 null 9. Kb7 null 10. Ka8

```

Note that the only way for the knight to reach d4 in two moves is if it makes both its moves before the pawn moves, and hence before the king moves. Once the knight is on d4, there is only one route for the king to reach a8 in seven moves.

---
Tags: problems, records
---


# Question
Title: In the endgame, black had only two blocked pawns. It is his turn. Is it stalemate or must he move his king?
In the endgame, Black had only two blocked pawns. It is his turn. Is it stalemate or must he move his king?

My opponent claimed that the king cannot move if all other remaining pieces are blocked.

# Answer
> 2 votes
> My opponent claimed that the king cannot move if all other remaining pieces are blocked

Whether the king can move has nothing to do with other pieces being blocked. It has to do with all the squares it can go to being attacked by one or more enemy pieces. If the king has no **LEGAL** moves and all the other pieces are blocked and the king is not in check then *that* is stalemate.

Read the full rules here.

---
Tags: rules, endgame, stalemate
---


# Question
Title: What are the + (plus) and - (minus) and ? (question mark) in Lichess near elo?
What does the +58 mean here? How does a player with higher elo get +58 for beating me with white?

# Answer
> 14 votes
The +58 is how much White gained for winning. The -5 is how much Black lost for losing.

The reason the gain is so much higher is because White had a provisional rating. (This is indicated by the "?" after the 875.) Because White's rating was considered unreliable but Black's was reliable, White was going to gain or lose many points, and Black was going to gain or lose few points. This is a feature of the Glicko-2 rating system used by lichess. According to their FAQ:

> ... when a player is just starting out, their rating will change very dramatically, potentially several hundred points at a time. But after some games against established players the confidence interval will narrow, and the amount of points gained/lost after each game will decrease.

---
Tags: rating, lichess
---


# Question
Title: Why trade rook for bishop and knight in this puzzle?
The puzzle https://lichess.org/training/kFzbF has position

```
[Title "Black to move"]
[FEN "r3rnk1/1bq2pp1/1ppb1n1p/p2p4/3P1B2/P2B1N1P/1PPQNPP1/3RR1K1 b - - 1 16"]

```

and the solution is Rxe2 Qxe2 Bxf4.

Lichess's Stockfish gives this line is -5, and gives all other moves 0. Why?

I ran through several lines and don't see any unifying themes; for example, here is a line where I traded a bunch of pieces (while picking near-top moves):

```
[Title "Black to move"]
[FEN "r3rnk1/1bq2pp1/1ppb1n1p/p2p4/3P1B2/P2B1N1P/1PPQNPP1/3RR1K1 b - - 1 16"]

1... Rxe2 2. Qxe2 Bxf4 3. c4 Re8 4. Qc2 Rxe1 5. Rxe1 c5 6. dxc5 bxc5 7. cxd5 Bxd5 8. Nh4 Ne6 9. Bc4 Bxc4 10. Qxc4 Be5 11. Qe2 Bd4 12. Nf5 Qb7 13. Nxd4 cxd4 14. Rb1 Qb3 15. Qd1 Qa2 16. b4 axb4 17. axb4 Ne4 18. Qf1 Nf4 19. Re1 Qd5 20. f3 Ng3 21. Qf2 d3 22. Qxg3 Ne2+ 23. Rxe2 dxe2 24. Qe1 Qd4+ 25. Kh2 Qd1 26. Qc3 Qb1

```

and it's not clear to me that black is better until near the end.

# Answer
There is a lot going on, but first of all notice that the rook worth 5 is less than the bishop and knight worth 6. That said, that alone is nothing like enough to give a -5 advantage for black.

When you look at the exact transformation you get a few more clues: before the transformation, white's best placed piece is probably the dark square bishop, pointed down towards the queen and not easily attacked by black pawns without significantly weakening the black king. Eliminating it makes it that much harder for white to attack black's very well defended king and removes a defender of the white king.

That raises the question of why not to capture the bishop directly. The reason is that by taking the knight first, not only do you eliminate one of the defenders of the potentially weak d4 pawn, you also give yourself the queen-bishop battery, which combined with the potential for a pawn break c6 to c5 opening up the light-squared bishop (played later) puts a ton of pressure down towards the white king. In the continuation you posted, white is later forced into a losing two knights vs rook end game.

Basically, you end one point up with a nasty bishop pair pointed down towards white's relatively defenceless king (as compared with black's king for instance). That said I kind of feel like a rating of 1624 is pretty low to catch the nuances of the position - especially when you consider that in the game this is pulled from, a 2242 rated player totally missed the idea.
> 1 votes

# Answer
1...Rxe2 is the best move simply because a bishop and knight are better than a rook. Evaluations given by recent versions of Stockfish can sometimes be a bit impractical for humans, since if Stockfish can recognize a position as a type that *it* would always/almost always win, then it will evaluate it accordingly.

For humans, a more practical evaluation of your position might be something like -2.50, instead of -5. Dividing a big evaluation Stockfish gives by 2 is a good rule of thumb that I've found works decently for many positions, if you want an evaluation that is more realistic for human play.
> 1 votes

---
Tags: analysis, puzzles
---


# Question
Title: What happens after repeated incorrect draw claims?
Assume, one player is in severe time trouble and his opponent chooses to play on. He has a strong feeling that they may have reached the same position for the third time but doesn't have the time to carefully check.

I looked up the procedure in the current FIDE laws of chess

> 9.5.3 If the claim is found to be incorrect, the arbiter shall add two minutes to the opponent’s remaining thinking time. Then the game shall continue. If the claim was based on an intended move, this move must be made in accordance with Articles 3 and 4.

Can he stop the clock and call the arbiter? What would happen, if he was wrong for the 2nd, 3rd, etc. draw claim?

If it happens more than once, the opponent could claim that the first player was only doing it in order to alleviate his time pressure by stopping the clock and waiting for the arbiter.

Is the worst that could happen that the opponent gets 2 minutes for each incorrect draw claim, no matter their count?

# Answer
> Can he stop the clock and call the arbiter?

A player can always do this. However, according to the rules:

> 6.11.4
>
> If a player stops the chessclock in order to seek the arbiter’s assistance, the arbiter shall determine whether the player had any valid reason for doing so. If the player had no valid reason for stopping the chessclock, the player shall be penalised in accordance with Article 12.9.

Article 12.9 covers the possible penalties ranging from a warning through to expulsion from the event.

> What would happen, if he was wrong for the 2nd, 3rd, etc. draw claim?

The arbiter would decide if the player was being frivolous and if so take action under 6.11.4 above.
> 8 votes

---
Tags: rules, otb-chess, claim-draw
---


title: Was my opponent in check?

text:
# Question
Title: Was my opponent in check?
I’m new to chess and I had my queen on the left one space away from the king which was on the right and he was unprotected, is that check?

E.g., take the following sample position (note: not provided by the OP - if the OP would like to post the position they had in mind, please feel free to delete this edit):

```
8/8/8/8/2Qk4/8/8/2R3K1 w - - 0 1

```

# Answer
> 10 votes
After making your move, imagine it's your turn again. Would your queen be able to capture the enemy king? If yes, your opponent is in check. It also doesn't matter if some other piece protects that square or not.

If there's no legal move your opponent can do do remove their king from the danger, then you're not just giving check, but also checkmate!

---
Tags: beginner, check
---


# Question
Title: Is Silman's book 'How to Reassess Your Chess: Chess Mastery Through Imbalances' any good?
I don't know if book review is allowed in the site or not, but I am just starting with a position I found pretty confusing in his book.

```
[Event "?"]
[Site "?"]
[Date "????.??.??"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "*"]
[SetUp "1"]
[FEN "3r1rk1/1ppn1qp1/2n1bp1p/p1b1p3/2N1P2N/2P1B1P1/PP2QPBP/3R1RK1 w - - 0 1"]

1. Rd5 Bxd5 2. exd5 Ne7 3. Nxa5 Bxe3 4. fxe3 Nxd5 5. Nf5 *

```

> "2.Rd5!? (an imaginative try to infuse some energy into his position and regain the initiative-White is hoping for 2...Bxd5 3.exdS Ne7 4.Nxa5 Bxe3 S.fxe3 Nxd5 6.Nf5) 2...b6! ending the nonsense and leaving White in a quandary."

According to Silman, Rd5 was an inaccuracy whereas Stockfish says that it was the best move. And if you read the above text carefully then you will notice that Silman was trying to say that after 6. Nf5 White was better or the position is equal. But Stockfish says after Nf5 black is better. In reality, at some point the position was equal but Silman made it worse.

After the position, I am feeling like the book doesn't seem worth reading but IMHO, his other book (Silman's Complete Endgame Course: From Beginner to Master) was excellent and met Stockfish level as well.

# Answer
"!?" means interesting move, not inaccuracy. The symbol for dubious/inaccurate move is "?!".

Anyway Silman is considering 2...b6 to be the main response by Black. 2...Bxd5 is indeed inferior for Black.

Still, it's perfectly possible that Silman's book has some incorrect lines/evaluations. He didn't have Stockfish when he wrote it. That doesn't mean the book is not worth reading though. It's better to learn from an imperfect 2400 Elo player who can talk to you in human terms than trying to learn from a "perfect" machine that only speaks evaluation numbers.
> 16 votes

# Answer
As David answered quite correctly, there may be some incorrect lines and evaluations, as there will be in many books. That being said, Reassess Your Chess is one of the best books to read regarding chess strategy in my opinion.

This book is likely responsible for my biggest gains in chess understanding, even though I was severely underrated when I read it.

I would recommend getting a copy of the workbook once you have completed it, as it is full of positions for you to practice your newly acquired knowledge.
> 1 votes

---
Tags: books, middlegame
---


# Question
Title: Are randomly created Queen's Quadrille and Hippodrome puzzles always solvable?
I found two chess puzzles on chessvariants.com, Queens's Quadrille and Hippodrome.

I'm thinking of creating **random** Queen's Quadrille and Hippodrome puzzles with a computer program.

My question is can I always be sure that a randomly generated Queen's Quadrille or Hippodrome puzzle is solvable?

Should I additionally check if it is solvable after generating a random puzzle?

# Answer
> 1 votes
Are you asking whether all Queen's Quadrille and Hippodrome problems are solvable? They are not. There is a discussion on the Hippodrome page which you link to. Here is an example of a starting position which is valid both for Queen's Quadrille and for Hippodrome, and where no moves are available:

```
        5bbQ/4BRrB/4krRK/4NNnn/8/8/8/8 w - - 0 1

```

Perhaps you could consider a version of Hippodrome where the player gets to choose which of the 12 non-knight pieces is removed. Then it seems more plausible that all positions are solvable.

---
Tags: chess-variants, puzzles
---


title: Can you make a lucky brilliant move?

text:
# Question
Title: Can you make a lucky brilliant move?
Is it possible to make a brilliancy (a brilliant move) with luck? Or is it so rare that it can only be spotted by the best chess players?

# Answer
> Is it possible to make a brilliancy (a brilliant move) with luck?

Absolutely.

For adventurous players I think it is not that uncommon. They often make risky moves which they haven't calculated all the way through. Sometimes they work and sometimes they don't. Tal played a lot of brilliant moves which later were found to be unsound but his opponent's couldn't find the refutation over the board. Tal was lucky.

What happens at a lower level is you see what looks like a brilliant move and play it without calculating all the way through to the end. Several moves in your opponent makes a move you hadn't anticipated or seen which seems to refute your sacrifice. You break out into a sweat. You hunker down and start thinking hard trying to find a way out. After 10 or 15 minutes you find the right move and play it. A few moves later your opponent resigns.

Your original move was a brilliancy which you didn't have the ability or patience to calculate all the way through. If you had calculated a little bit further you would have found your opponent's apparent refutation and given up. You were lucky you didn't calculate that far and then you were lucky again when there was a good reply that kept your attack going after your opponent found the tricky move.
> 7 votes

# Answer
**Yes.** The proof is trivial. For any chess position where a legal "brilliant"1 move exists, then by definition there are at least *n* \>= 1 legal moves. Then even if a player randomly selects a move legal in such a position, there exists the possibility of playing a "brilliant" move.

In cases where a player is not playing random moves, the possibility still exists, though it may be with a low probability.

YouTube videos from chess Twitch streams abound with content where a lower rated player plays an incredibly strong move without knowing why it is so strong, or where a lower rated player plays a move not realizing they checkmate their opponent. Similarly, though maybe less often, strong players may play a move believing it is strong not realizing it leads to disaster.

1. The question is unclear on the definition for a "brilliant" move but the answer holds for any definition that is also a legal move.
> 4 votes

---
Tags: analysis, tactics, online-chess
---


title: Is chess a zero sum game?

text:
# Question
Title: Is chess a zero sum game?
"Chess is a zero sum game" is a claim you see often, even on this forum.

Game theorists will tell you that it is just obvious. Either the game is a draw, nobody wins or loses, or one side wins and the other loses. A win is equal and opposite to a loss and a draw is worthless. QED.

Economic trade is a classic example of a non-zero sum game. In fact it is a win-win game. If that weren't the case then there would be no trade. Nobody would trade freely if they knew they were going to lose in advance.

# Answer
> 9 votes
Edit: let me add something because this answer seems to be misunderstood. FIDE ratings are based on game scores (see the Mathematics of Elo Ratings. It was created by Arpad Elo as a method for calculating the relative skill levels of players in **zero-sum games** such as chess. A player's Elo rating is represented by a number which may change depending on the outcome of rated games played. After every game, the winning player takes points from the losing one. So, if chess is a zero-sum game, so are the FIDE ratings!

The question then is: are FIDE ratings a zero-sum game because of pairings of players with different K-factors? A question I reinterpreted in a more provocative way: is chess **empirically** a zero-sum game?

As stated in Brian Towers' answer:

> Not necessarily. My k FIDE factor is 20. If your's is also 20 then, yes, my loss will match your gain, but if you are a junior or still haven't played 30 games (I think) then your k factor will be 40 and you will gain double what I gain. Similarly if you have ever been over 2400 then your k factor will be 10 and your gain will only be half my loss.

In the May 2020 FIDE list of the standard rating (see here), I observe a distribution of K-values for 2,700 players rated with

* a Fide rating in April and May,
* at least one game recorded in the list of of May 2020.

The distribution is as follows:

```
     K      Freq.   Percent
    10        21     0.78
    20     1,704    63.11
    40       975    36.11
    Total  2,700   100.00

```

Then, I plotted the estimated probability density function of the difference between their rating in April and May (given that the formula for updating a player's rating is based on the expected and the actual scores of the games played). As expected, the difference is centered on zero because the points lost by some players are won by others.

However, the sum of points gained is greater (23,144) than the sum of points lost (-21,564), which represents an average gain of +0.59 per game. However, this average is not statistically different from 0! Conclusion: **we cannot reject the hypothesis that chess is (empirically) a zero-sum game!**

***One caveat***: I did not observe the results and matches of these players; I assumed that the points won by some players in this list are lost by others in the same list.

This aside, I like very much the point about the experience gained and the sharing of ideas during and after a game, which suggests that "chess is anything but zero sum"!

# Answer
> 29 votes
When I said chess is a zero sum game in that answer, I wasn't referring to anything involving ratings. Obviously if we include ratings then chess isn't strictly a zero sum game, since the gains and losses aren't always balanced out. But different rating systems are arbitrary, and aren't part of the game of chess itself.

Your question should be "Is the FIDE rating system a zero sum game?"

# Answer
> 22 votes
**Chess is a zero sum game**. There is 1 point available and it is divided over the players, what one gains the other loses. It is a simple concept with a simple answer. Tournament rules mention some very rare cases where the result is 0-0 or 0.5 - 0, but in my opinion those are "outside the game". That a mobile phone may ring is not really a matter for the game theoretical analysis of the game of chess.

**Chess games played in tournaments are not zero sum**, but the tournament as a whole is. There are many situations where e.g. neither player wins anything in case of a draw, but a win by one of the sides puts that player in a prize-winning position. Not zero-sum. But a chess tournament, viewed as a multi-player game, is *not the same game* as chess. And the tournament *as a whole* usually has a fixed prize pool and is thus again zero sum.

**Ratings are not a game at all.** They are a *method to estimate player strength* by some third party, not a system of "points" that you "win". I could have my own private system of ratings that I never tell you about, based only on published chess results. I don't think you can be considered to be playing a game if you don't even necessarily know of its existence. When Jeff Sonas computed what ratings would have been for players before 1970, where those players retroactively playing the ratings game? That is absurd. Ratings are not a game.

# Answer
> 8 votes
The main reason why people often claim chess in a zero-sum game is simple: it is!

Considerations about ratings, the joy of playing, the scoring system for a certain type of tournament... are not an intrinsic part of the game of chess. The utility function for chess only considers three values: win \> draw \> loss. The value for the first player determines the value for the second player. When player 1 sees their utility function maximized, player 2 sees it minimized and vice-versa.

Please note that the distinction between "sum-0" and "sum-1" is irrelevant here since chess strategy would be exactly the same if the scoring system were "0.5, 0, -0.5" rather than "+1, +0.5, 0". In contexts like business this distinction is important because you have the "0-monetary-value choice" of not participating. But once you are in a game of chess, the only way to opt-out is to lose

Chess if therefore a zero-sum game.. Your "chess career" may not be, though.

# Answer
> 6 votes
This answer ignores the question of ratings, instead looking at a setting like a tournament, league, or similar.

Here, a single game of chess is indeed zero sum, under the typical scoring rules (1pt for a win, 0.5 for a draw, 0 for a loss) and *assuming that the goal of players is to maximize points earned*. That this is "actually 1-sum, not 0-sum" does not go against this assertion: Since the number of games each participant/team gets to play is fixed, one might as well score (+0.5 / 0 / -0.5) without changing the resulting outcomes at all. (That is why typically, the interesting property of a game is really being constant-sum, and not necessarily zero sum. The former are sometimes referred to as "rescaled zero-sum games".) If the goal is *not* to maximize points earned, but rather e.g. to place as high as possible in a given tournament, it is well possible that a match is not zero sum; say, if both players would need a win to move up a rank, and losing or drawing would not make a difference by that metric.

It is important to point out that the zero-sum nature of a match does not arise from the fact "Either the game is a draw, nobody wins or loses, or one side wins and the other loses." alone. In football ("soccer"), the same is true, but games are often scored 3 for a win, 1 for a tie, 0 for a loss. Thus, a match is not 0-sum (or constant sum): Two teams would e.g. rather trade wins than tie twice. Two possible aims of the three points for a win rule are to incentivize more aggressive, arguably more interesting-to-watch play, and curb potential for collusion.

# Answer
> 4 votes
I've seen a lot of answers here discussing wins and loses, piece trades, and even ratings. Here is my take on chess being a "zero-sum game":

There are exactly two players, so any move, any trade, any event in-game, affects both players in the opposite manner. It is theoretically impossible for there to be a move that is net positive for both players, or a move that is net negative for both players. If players trade queens, this is not net negative for both players. It may be negative in varying degrees, but the net result is simply how it affects each players' odds of winning, and since there are only two players, if player 1's odds go from 60% to 65%, then player 2's odds decrease by 5% as well.

# Answer
> 3 votes
A game of chess, considered as an abstract game, is a zero sum game. A game of chess, considered as a way to try advance one's rating may or may not be a zero-sum game; it depends on the rating system. A game of chess, considered as a human activity, is not a zero-sum game, as both players may gain pleasure from it, whether or not one loses.

# Answer
> 2 votes
A different take on the question "Is the FIDE rating system a zero sum game?": one could define a player's scaled ELO rating with the formula

```
scaled_rating = ELO_score / k.

```

By the definition of ELO scores, this quantity is zero-sum: if I play a game against you, then your scaled rating change plus my scaled rating change is exactly zero.

There are two exceptions, because of how the factor k is defined:

* When you turn 18 or play your 30th game, your scaled rating doubles.
* When you first pass 2400, your scaled rating doubles.

These are always positive variations, and when a new players gets a FIDE ELO score it is positive. So technically chess is a positive-sum game: the sum of the scaled ratings of all players in the world (living and dead) is an increasing quantity.

However, the events that make this sum increase are probably not what you imagined. (In particular, there are at most 3 in the life of each player).

# Answer
> 1 votes
The claim that chess is a zero-sum game is clearly nonsense, apart from in the most theoretic way. Just looking at the scoring system gives the game away -

Win = 1 point
Draw = 0.5 points
Loss = 0 points

Clearly it is a one-sum game :-).

OK, joking aside, what about rating? Surely if we play a game and the game is rated then what one side gains in rating points will be matched by the other side's loss in rating points? Rating-wise it is zero sum.

Not necessarily. My k FIDE factor is 20. If your's is also 20 then, yes, my loss will match your gain, but if you are a junior or still haven't played 30 games (I think) then your k factor will be 40 and you will gain double what I gain. Similarly if you have ever been over 2400 then your k factor will be 10 and your gain will only be half my loss.

Putting these purely numerical factors aside it is clear that it is mostly a non-zero sum game. There is a FIDE rule which says that for a game to count as being played for rating purposes each side must have made at least one move. The event which lead to this rule was a weekend tournament in the 1970's when Tony Miles (England's first OTB GM) and Stewart Reuben (later an IA and long time member of FIDE's Rules Commission) agreed a zero-move draw. This guaranteed Miles first prize and gave Reuben a share of second prize. For them it was win-win, at least until the organizers saw what they had done, disqualified them and asked for the money back!

Whenever I play a serious/rated game against a much stronger player it is clear that even if (when!) I lose I don't actually lose anything real and in fact I gain. I gain the experience of having my ideas tested by a much stronger player. If there is time after the game and my opponent agrees to a postmortem then I also gain a free lesson.

Clearly chess is anything but zero sum.

# Answer
> 1 votes
The problem is whether to add or subtract a draw. Subtract 1/2 from 1/2 and you get 0, but add them and a draw is a "win-win" and as a popular site says "a wild game that ended peacefully," which is cold comfort if both spiders are dead, or both prisoners in the classic zero sum prisoner's dilemma end up in jail!! There is stochastic resulting bias if at a game state complexity of 10^123 (log of branching factor 35^80 plies) results in chance-like choices at the edge of chaos.

# Answer
> 1 votes
I would like to bring in the point that it is wrong to consider chess a game being played for the result. Both sides have to play trying to overcome or withstand the other side to play chess, but that does not mean that we play chess in order to win. Nor does it mean that what is- intrinsically- to be won in the practice of chess is deducible from the score.

Just a few examples: Quite obviously, a good game is more of a win-win game than a game played poorly by either side.

If you try to become a better fighter, losing or winning is not the key factor by which you value your gain.

It is intrinsic to chess that it is played by beings with vision and agency. It is hard to give engines this credit. Even though they exploit-apply vision and agency, we do not see them as beings- they need not be beings to do what they do. I'd say engines, computers can not play a game of chess, yet (it is not what they are set out to do, yet), and therefore they can not win, draw or lose a game, while for us playing them, the result is 0, 1/2 or 1 (in order of frequency).

The establishment of the rules of mate and stalemate can be seen as a win-win woven into the fabric of chess: the defender gets more credit in form of more points, the attacker gets more credit for making the difference against the harder odds. You could argue the other way round that it was far too easy to achieve stalemate, and it were lose-lose: The attacker frustrated without the resource of a stalemate win, the defender bored and inexact with stalemate draws just too easy to bring home. (It's the first one, isn't it)?

The zero-sum thing is importantly giving shape to the game, we have to play to mate or save the kings. But it is also unimportant in as far as it does not reflect lots of things counting for us, like, for example, the love for wood.

# Answer
> 0 votes
The only times chess is not a zero-sum game are in situations described by a famous Tal quote: "You must take your opponent into a deep dark forest where 2+2=5, and the path leading out is only wide enough for one." In that case chess becomes, after simplifying the equation, "+1" sum game.

---
Tags: psychology, evaluation
---


# Question
Title: Tournaments with not-everyone-treated-equal
Less "radical": see also this question.

Usually, in tournaments rules hold uniformly for each participant. Here are some examples that might violate the rule:

* A: Those who can't notate (very young players, disabled) may have an assistant. (Usually they get a slight time malus in return. Official rules: E-01-8.1.6 and E-02)
* B: For very young players, also other measurements may be taken (e.g. playing without clocks), but this usually then holds for everyone (U8 tournaments and such) and thus no violation of the above principle.
* C: Sometimes in DWZ (German rating system) club tournaments, the weaker player gets compensated with a time bonus, but usually only in "fun" tournaments.

Was there ever a "large" (even FIDE) tournament where "weaker" people got a bonus beyond A and more in the line of C?

# Answer
> 3 votes
This is kind of an opposite of an answer, but McMahon system is a modification of the Swiss system where players are awarded starting scores according to their rating: the higher rating, the higher starting score. The logic is that we "pretend" that the first few Swiss rounds have been played, and the higher-rated players were paired with significantly lower-rating players and won their games.

This may sound extremely unfair, and McMahon system is rarely if ever used in chess, but it's quite common in Go. Go has no draws, and the result of a game between two players of different level is much more "deterministic" than in chess. So, it really makes sense to avoid such pairings.

Incidentally, when Morozevich picked up Go, there was some over-excitement about his results as reported on chess websites unfamiliar with McMahon system, such as "he scored 9/9 in a the European Go championships". True, this does not nearly imply he won!

---
Tags: rules, tournament
---


# Question
Title: Am I obligated to tell my opponent the position of my piece he displaced in blitz?
In a blitz game, my opponent displaced 3 pieces upon capturing. He arranged 2 correctly but could not figure the position of the third piece. Am I obligated to say the position of the 3rd piece when he asks?

# Answer
> 11 votes
There is nothing in the rules which says you have to tell your opponent the correct position of the piece. However, if you think about it for even just a few seconds the drawback of not saying should become obvious.

Let's go through it.

1. Your opponent asks you where the piece should go and you either say you don't know or just ignore them.
2. Your opponent thinks "OK, he has no clue" and then puts the piece back in a losing position for you.
3. Suddenly you come to life. "No! No!", you say. "It goes here!"
4. Opponent calls the arbiter. Explains that 2 seconds earlier you had no clue but now you "know" where the piece was. Says you were right first time and you are just trying to avoid what was already a lost position for you.
5. Regardless of the arbiter's decision you have lost credibility with the arbiter who is now less likely to believe you the next time you are involved in a dispute.

# Answer
> 1 votes
Here's the quote from FIDE rules:

> If a player displaces one or more pieces, he shall re-establish the correct position on his own time. If necessary, either the player or his opponent shall stop the clocks and ask for the arbiter’s assistance. The arbiter may penalise the player who displaced the pieces.

So, but the rules of chess, it would be their responsibility to restore correct position and you are under no obligation to help them. If they did it wrong, you should stop the clock and call the arbiter; the arbiter may penalize your opponent e.g. by adding you time.

---
Tags: rules, blitz
---


# Question
Title: What do modern chess players understand about the game that previous generations did not?
In an interview, Garry Kasparow stated that each generation of chess players knows more about the game than the previous one. He applies this thought concretely to the question of who is better - him or Magnus Carlsen. He seems to imply that Carlsen is the stronger player because of this.

What are the kinds of things that succeeding generations have learnt? Have there been well-known breakthroughs in understanding chess?

# Answer
The knowledge of previous generations was summed up in Aron Nimzowitsch's book, published in 1929, called *My System*. The advances in chess knowledge up to Kasparov's time are best summed up in John Watson's 1998 book *Secrets of Modern Chess Strategy: Advances since Nimzowitsch*.

It is perhaps worth revisiting *My System* to remind ourselves of some of what was knowledge in 1929:

1. Control of the center, by both pawns and pieces
2. Rapid development
3. Prophylaxis as both overprotection of important squares and thwarting the opponent's plans
4. Strengths and weaknesses of the IQP (isolated queen's pawn)
5. The importance of the two bishops
6. Pawn chains (e.g. French Defense)
7. Importance of open files and of the 7th and 8th ranks for rooks
8. Centralization of the king and minor pieces in the endgame

In between Nimzowitsch and Watson it's worth mentioning Ludek Pachman and his 3 volume *Complete Chess Strategy* first published in Czech in 1960. He deals extensively with the **Minority Attack**, which was around in Nimzowitsch's time (Capablanca used it) but didn't make it into *My System*.

Watson's main departure from Nimzowitsch centers around his principle of **Rule Independence.** What this boils down to is the idea that rules, a la Nimzowitsch, are for general guidance only and are not set in stone. Calculation is more important than rules. In this respect Watson captures the essence of modern chess in the age of computers. Perhaps also worth noting that Kasparov was the first of the computer generation pioneering, as he did, use of Chessbase.

To demonstrate the principle of rule independence Watson borrows an Andy Soltis example:

```
[fen ""]
[Title "Khlavin vs Zhdanov, Latvian Champs 1961"]
[Startply "20"]

1. e4 c6 2. Nc3 d5 3. Nf3 g6 4. d4 Bg7 5. h3 a6 6. Bf4 Nf6 7. e5 Ng8 8. Qd2 b5 9. Be2 h6 10. O-O-O e6 11. g4 Nd7 12. Bg3 Bf8 13. Rdf1 Nb6 14. Nd1 a5 15. Ne1 b4 16. Nd3 Nc4 17. Qe1 Qb6 18. b3 Qxd4 19. bxc4 Qa1+ 20. Kd2 dxc4 21. Nf4 Qa2 22. Ke3 Bb7 23. Qd2 g5 24. Nh5 c3 25. Qd3 Rd8 26. Qe4 Bc5+ 27. Kf3 Rd4 28. Qe3 Qd5 0-1

```

After Black's 10th move Soltis writes, sarcastically,

> It doesn't take long to conclude that White has a very strong game. He has developed nearly all of his pieces while Black's only developed piece, his king's bishop, bites on granite. Black's queenside is full of holes on dark squares and he has just locked in his queen's bishop. A quick mating is assured, you might conclude. And you'd be right.

Dynamics change everything. Pieces gain their values not from a hard and fast rule but from the position and their possibilities which are ever changing. The **Initiative** has a value which can also change everything. Watson devotes a chapter to the **Exchange Sacrifice**.
> 26 votes

# Answer
This question needs a book. A rough sequence of changing understanding could be.

1. importance of rapid development, control the center, and activity.
2. importance of positional considerations over activity, endgames.
3. importance of activity in consideration of position. Positional Exchange Sacrifice. Accepting structural problems to achieve activity.
4. professionalism, deep preparation, opening and endgame mastery.
5. importance of concrete calculation over all other considerations. Attuned to the exceptions of the rules to the position at all times.

This is a woefully inadequate list. I could tell a whole story just about time controls and time management. To learn more about Garry's take I recommend his amazing series "My Great Predecessors."
> 9 votes

# Answer
I disagree with most (though not all) of the points mentioned in existing answers, and find them to arise from a rather naive and unsophisticated understanding of the game. I will first begin by explaining why some the points already mentioned are NOT the answer to the question.

One of the existing answers presents the answer as saying that prior to the modern era, people believed that chess was based on rules like controlling the center, whilst the new advances involve the "initiative" and "exchange sacrifice" and an understanding of "rule independence". This is totally ridiculous, because players all the way back to Paul Morphy, one of the earliest 'great' players of the game, played extraordinarily "romantic" chess which was all about sacrificing pawns for activity. Tal is also another famous, more recent example. To the contrary, modern players are more likely to play slow, maneuvering chess compared to the "romantic" era of Morphy and Andersson, like the countless Berlin defences (popularised by Kramnik in the 2000 World Championship against Kasparov) and Ruy Lopez and Giuoco Piano slow maneuvering chess seen nowadays at top level.

The books by Nimzowitch and Watson, and indeed any chess book in general, merely represent the points that the author thinks to be instructive for the reader and valuable to include in the book. The idea that this can be taken to be a summary of existing knowledge in chess, many aspects of which (e.g. a strong chess player's "intuition") is not even possible to really write down in a book the first place, is rather naive. All of the points mentioned in Nimzowitch's book was surely already understood to some depth by Paul Morphy, and even by any average 2000 rated player in 1900 or in the modern day. For example, the "exchange sacrifice" is an idea that even 1000 rated beginners have probably heard about, and these surface-level words and phrases have no relevance to the process of thinking at top-level chess. This has absolutely nothing to do with what Garry Kasparov was talking about when he mentions the advance in chess knowledge.

---

The real difference primarily lies in **opening theory**.

Prior to the age of engines, strong players who are looking to gain an advantage as white in the opening would need to discover these ideas for themselves through extensive analysis and great creativity. In complicated positions, it may often not even be clear whether or not a certain idea is good; evaluating these positions is a very difficult and sometimes tedious task (in terms of analysing lines). Nowadays, if Magnus Carlsen were trying to prepare for a World Championship match, he (or his team of seconds) could simply look to the engine for reliable analysis of lines and there is more or less no chance of making a severe error in analysis that could cost him the game by walking accidentally into a lost position out of the opening. Of course, there is still a lot of work to be done, in the sense that the opponent has access to engines too so it is difficult to come up with creative ideas to surprise the opponent, but it is still a great advantage in terms of quality of analysis compared to the pre-engine era.

Additionally, from the decades of games that have been played since Kasparov's time, chess theory in various popular openings have developed and improved, so that the top players know a lot more details about various lines than Kasparov would have been able to know. This is simply because more ideas would have been played by strong players, winning some nice games, and everybody (in the top-level chess world) takes notice and learns the lines too. Some topical examples includes detailed analysis in popular lines such as the Najdorf and Berlin, as previously mentioned. (Though I will admit that I am not strong enough to give detailed analysis of all of the intricacies of these lines and how they evolved over the past 20 years, and you should probably not believe anyone who claims to do so unless they are a strong GM.)

Another concrete example is that of openings like the King's Indian Attack, King's Indian Defence, and Queen's Indian Defence, all of which have been borderline refuted by engines. For example, in computer championship games, the side which plays the opening has an overwhelming disadvantage and loses a large proportion of the games. This is true even for openings like the Caro-Kann and the French defence. This has led to a drop in popularity at top level for many of these openings, when they had been popular even just a decade ago. For example, the famous game Gelfand-Nakamura from 2010 ("Nakamura's immortal") is a great example of a tremendously complicated middlegame where Nakamura won in the King's Indian Defence with the black pieces, where a critical position involving queen sacrifices on consecutive moves occurred.

```
[fen ""]
[Title "Gelfand vs Nakamura, World Team Championships 2010"]
[Startply "48"]

1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. Nf3 O-O 6. Be2 e5 7. O-O Nc6 8. d5 Ne7 9. Nd2 Ne8 10. b4 f5 11. c5 Nf6 12. f3 f4 13. Nc4 g5 14. a4 Ng6 15. Ba3 Rf7 16. b5 dxc5 17. Bxc5 h5 18. a5 g4 19. b6 g3 20. Kh1 Bf8 21. d6 axb6 22. Bg1 Nh4 23. Re1 Nxg2 24. dxc7 Nxe1 25. Qxe1 g2+ 26. Kxg2 Rg7+ 27. Kh1 Bh3 28. Bf1 Qd3 29. Nxe5 Bxf1 30. Qxf1 Qxc3 31. Rc1 Qxe5 32. c8=Q Rxc8 33. Rxc8 Qe6 0-1

```

Despite this incredible win, which you might expect means that the popularity of the King's Indian Defence would surge amongst top level players, if you check the database, the last time Nakamura has played this opening as Black in a classical game was against Lenderman in the US Championships 2018 which ended in a draw. He has rarely played this even in rapid and blitz in serious tournaments since 2019. You will see similar trends if you look at the openings played in tournaments like the Candidates with a surge in popularity of reputable openings like the Ruy Lopez and fall in popularity of these imbalanced (and arguably engine-refuted) lines.

Hypermodern openings such as 1.b3 (Larsen's opening), 1.g3 or the Grunfeld offer an example that is less recent but maybe easier to understand. These openings were deemed to be dubious since they violated classical opening principles, opting to control the centre with long-ranged pieces (like a fianchettoed bishop) rather than pawns. The Grunfeld, for example, relies on active counterplay and undermining White's strong (but overextended) pawn center, where Black actively gives up center control. But once people such as Bent Larsen (a former 4-time World Championship Candidate) started playing moves like 1.b3, top players realised that hypermodern ideas were not as bad as once thought; indeed, these have now become popular openings in online blitz (with Nakamura, the currently FIDE blitz rated #1 in the world frequently playing 1.b3 in online blitz) and even in serious classical OTB tournaments (Maxime Vachier-Lagrave famously has the Grunfeld in his repertoire). To be clear, these openings have been known since more or less the 1920s, so Kasparov definitely wasn't talking about them when referring to new knowledge of modern players. Nevertheless, they offer an illustrative example of the nature of advance of chess knowledge that is easier to understand for non-GMs.

**TL;DR** What do modern chess players understand about the game that previous generations did not? The answer is **detailed intricacies in many different lines of opening theory**. This is why it is reasonable to think that Magnus Carlsen, or maybe even Fabiano Caruana, or Levon Aronian, or Ding Liren, or Ian Nepomniachtchi, at their peaks would likely (or at least have a real chance to) best Garry Kasparov at his peak. It is simply an unfair comparison because Kasparov did not have the advantage of knowing these few decades of opening theory that have developed, aided by modern engines, since his retirement. **These concrete lines, variations and details are the difference, not some vague claims of "inventing a new style of chess" or "rule independence", which are total nonsense.**
> 6 votes

# Answer
I'd second that this answer needs a book (I'd read it). Any new edition though is bound to summarize all of the beforeanswers, which I'll call "the classics", and incorporate what AlphaZero "invented" as a new style of chess, which may very well go along the lines laid out above.

These last five years however have shown that the matches between it and e.g. Magnus Carlsen have spawned new schools of thinking. Carlsen employed "new" moves into his own playing since. Any answer to the questions very much ought to include these recent developments.

Since I lack serious playing skills myself (and just made this account to contribute) here is what I'd expect to be spelled out in it:

* in their 2019 book *Game Changer*, Natasha Regan and Matthew Sadler spell out how AI plays differently and "inhuman"
* "No matter whether efficiency means sacrificing material or being incredibly solid, they will do what is required! Regardless of whether they are the pinnacle of AI or the Chess World Champion." - referring to players. Quote from https://www.newinchess.com/media/wysiwyg/product\_pdf/873.pdf
* a paper by company DeepMind, *Acquisition of Chess Knowledge in AlphaZero* should also provide insights
* On chess.com theres also a lengthy article with much appreciated details: https://www.chess.com/news/view/how-alphazero-learns-chess
> 1 votes

# Answer
YiFan's answer is excellent, but I think one piece of knowledge that emerged with the advent of computers can be formulated concisely: **we are now much more confident that chess is a draw.**

Before, at top-level chess White often played the "most critical" line in the most topical opening, Black responded in kind, and they would debate whether white gets a winning advantage or not. Kasparov won plenty of games out of the openings, and one may say he was arguing, by his play, that chess is a win: "I have an advantage in the most principal line, and I also have an advantage in sidelines, because they are inferior."

Nowadays, while some lines were "refuted", the overall trend is that black can make a draw in many, many ways - *most* sound opening systems have a path to equality. Not only these old main lines are a draw, but also many of the "inferior" sidelines are drawn, in more than one way. So, nobody is trying to prove that they can get opening advantage against the best play, like Kasparov did in his time. It has shifted to surprising the opponent.
> 1 votes

---
Tags: strategy, theory, history, study
---


# Question
Title: Rated Correspondence Chess for a French Federation Member
As a member of the French chess federation, I am somewhat disheartened to see that the only way to play for an official rating is on ICCF. I do not wish to play on ICCF as I dislike the use of engines and tablebases in correspondence chess.

Is there a place that I can play for official ratings that does not allow engine use? USCF springs to mind, but I am not sure I can play there while being associated with the French federation. Is this at all possible?

# Answer
> 3 votes
I have been an International Chess Correspondence Federation (ICCF) delegate of a country for 20 years. So, the answer to your question is that you cannot transfer from France to USA in the ICCF without the approval of the French federation. But, in general federations would accept a transfer. You would have to contact the French Federation. However, the United States Chess Federation (USCF) accepts members even if they are not U.S. citizens. So, you can play in USCF tournaments. Note that USCF and US ICCF are not the same. USCF belongs to FIDE, but US ICCF belongs to ICCF. If you decide to do that, check that some U.S. tournaments do not allow chess engines, but others do because the U.S. is also a member of the ICCF. A good question is what is an official tournament? ICCF is the elder correspondence chess federation, but ICCF and FIDE are not 100% connected anymore. My suggestion would be that you play correspondence chess on lichess.org. ***Lichess do not allow the use of chess engines.*** Is it official? Why do you care about that? Lichess is the main chess server because it is 100% free. 250,000 members!!! For me that is an official system. Lechenicher Schach Server offers correspondence chess games without engines as well. Even they offer their website in French: https://www.chess-server.net/fr/ Lechenicher is also 100% free. However, be careful because they also have tournaments where the use of chess engines is allowed. Just register in the right tournament. My guess is that there are many other websites that offer correspondence chess without engines. Just do not limit yourself with the requirement of "official." At the end of the day, nobody cares about our chess rating except ourselves. Good luck with your chess journey! Hugs!

---

***Update:***

LSS now has a rating list for correspondence chess for players that do not use software programs (chess engines).

LSS is 100% free. An excellent server that I highly recommend.

---
Tags: rating, correspondence-chess
---


title: Why Bxa2 is bad according to Silman?

text:
# Question
Title: Why Bxa2 is bad according to Silman?
```
[FEN "2nr1r2/1pp1q1pk/2n1bp1p/p3p3/4P2N/2P1N1P1/PP2QPBP/3R1RK1 b - - 0 1"]

1... Bxa2 2. Bh3 Nb6 (2... Nd6 3. Rxd6 cxd6 4. Bf5+ Kg8 5. Ng6 Qf7 6. Nxf8 Qxf8)

```

I found the above position in *How to Reassess Your Chess* by Jeremy Silman. He said that after 1...Bxa2 2. Bh3 Black is suddenly dead meat. But according to Stockfish, 1...Bxa2 is the best move.

Why did Silman think Bxa2 is bad?

Silman wrote in the starting page that he used Fritz and Deep Blue. They are not better than Stockfish as everyone knows. But Silman also added that he got help of some IM and GM. Also, he analyzed the positions.

Instead his continuation was 1...Nb6 2. Nd5 Bxd5 (Stockfish suggests Qf7. As a human, I also don't like Knight on d5 so I will also consider taking it with the bishop since knight take d5 is blunder cause exd5 forks bishop and knight) 3. exd5

# Answer
> 1 votes
I agree with Hauptideal's general answer, but for this specific position perhaps I can add a suggestion why 1...Bxa2 might not be very human even if the engine does enjoy the position afterwards.

The problem here is the f5 square. Both of white's knights are staring at that square, and if a knight does land there it does so with a tempo on the black queen, and very near the black king too. You could imagine that in some worst case scenario, if the black queen wanders off to the queenside, say, white might be able to play moves like Qh4 at some point and black would have to worry about king safety. Even if not, the fact that there is a knight on f5 that is more or less impossible to remove (even if you try to trade with ...Nd6, the other white knight takes its place) is not very nice from a human perspective and white gets more than enough compensation from the pawn, or at least so it would seem to a human playing this game.

If 1...Bxa2, the point of Bh3 is not just to control the light-squared diagonal but also more concretely the f5 square. There are ideas of not just Nf5 now, but also Bf5. To help to understand this position consider a concrete line where I will play human moves for black and engine responses for white: 1...Bxa2 2.Bh3 Nd6 3. Rxd6! Qxd6 4. Rde1 Qe7 5. Bf5+ Kg8 6. Nd5 Bxd5 7. exd5 Nb8 8. Be6+ and black is lost.

```
[FEN "2nr1r2/1pp1q1pk/2n1bp1p/p3p3/4P2N/2P1N1P1/PP2QPBP/3R1RK1 b - - 0 1"]

1... Bxa2 2. Bh3 Nd6 3. Rxd6 Qxd6 4. Rd1 Qe7 5. Bf5+ Kg8 6. Nd5 Bxd5 7. exd5 Nb8 8. Be6+

```

If you ask the engine, turns out the critical mistake was 6...Bxd5, but this doesn't seem like an outrageous move to a human because the black bishop is stranded on a2 and this not just solves the problem of the off-side bishop but also eliminates a seemingly powerful white knight. But concretely, black loses due to weaknesses around his king. Even if black does not fall victim to this blunder, if you look at the lines, there is often only one move that maintains equality or very slight advantage for black (less than -0.5, let's say) and every other move is a huge advantage for white. This is why the position is tough from the perspective of human intuition and strategy, even at GM level, despite the fact that Stockfish seems unconcerned about grabbing the pawn.

# Answer
> 6 votes
In every classic book, you'll have lines that modern engines do not like. I stumbled on the very position when I read the book, and I remember the phrase "dead meat" being extremely cryptic to me. However, I found, that Silman's books are much better than, say, Chernev's Logical Chess Move by Move (which I stopped reading precisely because of the bad objective quality).

It is very good that you check everything with an engine, that you do not understand. However, even if a modern engine considers a variation better than Silman, **it is still very valuable to read and understand Silman's annotations**, because you'll learn something about **practical** "human" moves and **how to generally think about positions**, even if *concretely*, a certain other variation might work slightly better. Often, these better variations are hard to assess for humans correctly, because a lot of complications are to be considered or a great calculation depth is needed to see the point. In short, they are impractical, and it's hard to deduct a general strategic pattern/rule from these moves. The goal of "How to reassess your chess" is not to make stockfish-like calculation machines out of you, but to teach you strategic concepts, and his moves are always "good enough" for practical play and learning strategic ideas. Especially in a book about strategy, there will be alternatives and multiple possible avenues, but he chose one specific line to demonstrate an idea to you. Of course, you may not *have* to maneuver your knight to that juicy outpost, for example, but it's pretty good to do it and he can prove his point that you sometimes can and should invest the time to get your pieces to good squares. Yes, there may be another variation the computer might play, but you wouldn't have learned the concept.
In a few years, a new chess engine might laugh at your Stockfish 15, just as Stockfish 15 now laughs at the engines Silman used to write his books. **The strategic principles, however, stay**. When you find an example, where Silman is very wrong objectively, you should of course skip this particular example or not take it too gravely (in the example, the move is so impractical for Black that even an International Master would refrain from doing it (even if objectively, the ?? may be wrong, it may be correct practically..). This is the exception in this book, anyhow.

> Should I throw the PDF right now?

Yes, but only for you to read the hard copy. Please buy the book if you can afford it. There are no legitimate (scanned) PDFs from Silman's works. But I would keep reading because you can still learn a lot from Silman.

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Tags: analysis, middlegame
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# Question
Title: Opponent replies to a half made move - what should the arbiter do?
In round 1 of the recently concluded 4th EJCOA IM norm tournament this game was played:

```
[Title "Rajat Makkar vs Neil Berry 4th EJCOA IM Norm 2022"]
[fen ""]
[Startply "36"]

1. d4 Nf6 2. c4 e6 3. Nf3 d5 4. Nc3 Be7 5. Bf4 O-O 6. e3 Nbd7 7. c5 c6 8. b4 b6 9. h4 a5 10. a3 h6 11. Bd3 Ba6 12. Bxa6 Rxa6 13. b5 cxb5 14. c6 Qc8 15. c7 b4 16. Nb5 a4 17. Qc1 Ne4 18. Qc6 Nb8 19. cxb8=N Ra5 20. O-O g5 21. hxg5 hxg5 22. Bc7 1-0

```

In the position above Makkar had a long think before getting up and saying something to one of the Black players on an adjacent board who was watching the game. The player smiled, nodded, went back to his board, took a white knight he had captured and handed it over to Makkar who then made his stunning move. All great for the arbiter who didn't have to get out of his seat.

I wondered, what if it had gone differently? Suppose White had captured the knight with the pawn, left the pawn on the 8th rank, paused the clocks and raised their hand to call the arbiter to ask for a knight. Suppose Black had immediately flashed out the move QxQ. What should the arbiter do?

Just to recap some of the rules.

1. A player is allowed to reply to their opponent's move after the move is made but before the opponent complete's the move by pressing the clock.
2. If a player completes (by pressing the clock) a promotion move leaving the pawn on the board then that is an illegal move. Along with the usual punishment the arbiter should remove the pawn and replace it with a queen.
3. If a player touches one or more of their pieces, they must move the first piece touched that can be moved
4. If a player touches one or more of the opponent’s pieces, they must capture the first piece touched that can be captured
5. Only the player having the move may adjust one or more pieces on their squares provided they say “j’adoube” or “I adjust” or something similar
6. Any other physical contact with a piece, except for clearly accidental contact, shall be considered to be intent
7. A player is said to ‘have the move’ when the opponent’s move has been ‘made’.

What should the arbiter do?

# Answer
Rule 4.7.3 says:

> The move is considered to have been made in the case of... promotion, when the player's hand has released the new piece on the square of promotion and the pawn has been removed from the board.

The move has not yet been made; there's no way a move can be "half made" under the rules. So Black does not "have the move".

This is technically not an illegal move, because

> 3.10.2 A move is illegal when it fails to meet the relevant requirements of Articles 3.1 – 3.9

The player has violated the rules, but *not* any of the rules in 3.1 - 3.9, which govern *how* the pieces move but not *when*.

It is also not a touch-move violation, as 4.3 and 4.4 specify that the player must have the move to violate them. It is perhaps best categorized as a violation of rule 1.2:

> The player with the light-coloured pieces (White) makes the first move, then the players move alternately, with the player with the dark-coloured pieces (Black) making the next move.

The arbiter should proceed in the same way as if one side had made two moves in a row. There does not appear to be a specific penalty for this, but proceeding with the same penalty as an illegal move would seem appropriate, since it's the same general sort of violation even if it's not technically an illegal move.

So, Black is not under any obligation to move his queen or take White's queen because he did not have the move when he touched them, but should be penalized for moving without having the move. White, having touched the pawn and black knight, must take the knight and promote, but does not have to use the knight he's getting from the other board. (Although, if he doesn't, he may be subject to penalties since then he's paused the clock without a good reason.)
> 7 votes

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Tags: rules, arbiters
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