# Question
Title: SCID on Mac doesn’t load database on startup
I installed SCID on my Mac (Ventura 13.1) and I was able to load a database of games. I right clicked and selected “Load at startup” but after I close and reopen SCID I only see the Clipbase.

I tried both SCID 4.8 and the 5.0 beta. Same results :(

I also tried restarting my Mac but no luck. (The layout wasn’t saving for some reason, but this was solved with a Mac reboot)

# Answer
> 1 votes
It sounds like there may be an issue with the way SCID is saving the database settings when you load it at startup.

Here are a few things you can try:

Make sure that the database you want to load at startup is the default database in SCID. To do this, go to File \> Set Default Database and select the database you want to use.

Try manually opening the database you want to use after SCID starts up. To do this, go to File \> Open and select the database you want to use.

Check the preferences settings. Some versions of SCID have an option in the preferences to load a specific database at startup. This option can be found in the File menu, in the preferences section.

Try saving the layout of the database with the layout you want. In some versions of SCID, the layout isn't saved after closing the program, so it's necessary to save it manually by going to View \> Save Layout.

Try using a different version of SCID and see if that resolves the issue.

If none of these steps solves the problem, it may be a bug in the version of SCID you are using, and you may want to contact the developer for assistance.

---
Tags: scid, macos
---


title: Percentage of kids that "stay"

text:
# Question
Title: Percentage of kids that "stay"
Just for fun, I'm going through my ancient games. Who? Never heard of? Vanishville?

As a kids trainer I of course know that only a tiny percentage will become "professionals" (and I merely mean that they play for our team of adults, not that they earn money). Is there solid data on the concrete amount (which of course locally varies due to size of the club, available trainers, social milieu etc. pp)?

# Answer
> As a kids trainer I of course know that only a tiny percentage will become "professionals" (and I merely mean that they play for our team of adults, not that they earn money).**Is there solid data on the concrete amount?**

The simple answer is "No" because the question appears to be carefully constructed to NOT have any meaningful data.

If you has asked about the percentage of children aged under N playing FIDE rated chess who are still playing FIDE rated chess N+m years later then that could be answered.

Here in England there *is* data available to organizers and arbiters regarding children's dates of birth which could be used to suggest some kind of answer but that data is problematic.

First, it is not available to the general public because it is open to child protection issues. So, there is no way of independently verifying any results.

Second, it does not include data for children who never played an ECF rated competition. That probably already excludes a significant number of children.

Third, playing for an adult team is a very variable bar. In our club we have had at least one (adult) player play for a team with an ECF rating under 1000 and we currently have adult players playing for lower level league teams for us rated about 1300. I don't think those examples would count as "professional" in any sensible definition of the word.
> 2 votes

# Answer
The best indication I can come up with is: how many kids playing rated tournament chess are still playing rated tournament chess 10 or 20 years later?

Out of 145 players in a junior USCF tournament I selected from late 1996, 17 of them have played a USCF game in 2007 or later. Only 7 of them have played a USCF-rated game since 2017. That's about 12% and 5%.

For comparison, out of 30 players in an adults-only competition held at the same location at the same time, 20 have played a USCF game since 2007, and 11 since 2017. That's about 67% and 37%.
> 5 votes

---
Tags: statistics
---


# Question
Title: Who is the Schmidt Variation of the scotch opening named after
in the scotch opening if black develops their knight on move 4, this is called the Schmidt variation, does anyone know who it's actually named after?

# Answer
Eugen von Schmidt (so 'von Schmidt variation' would have been a better name), who was one of the editors of 'Schachzeitung'. His analysis was published in the January issue of 'Schachzeitung', 1865.

For his original analysis (in German, of course), see https://books.google.se/books?id=y61AAAAAcAAJ&hl=sv&pg=PA2#v=onepage&q&f=false .

(Taken almost straight from Oxford Companion to Chess, which has useful info on a large number of openings, the names and their history, at least up to 1992 or so.)
> 3 votes

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


# Question
Title: Is there a way to get blunders, mistakes and inaccuracies using Stockfish?
Stockfish provides the best moves/lines but is there a command or technique to get inaccuracies, mistakes and blunders? How is this done by lichess or chess.com?

They also have the ability to show an evaluation chart throughout the game. Are they doing it iteratively move by move? Even in that case how can you categorize the moves as mistakes or blunders using Stockfish?

# Answer
Common methods for engine annotation include a strict evaluation model or the expected points model. In the strict evaluation model, engine annotations require user-defined parameters to classify inaccuracies, mistakes, and blunders using the strict difference in the evaluation between the move played and the engine's top choice.

In the expected points model, the engine's evaluation is mapped to a function between 0 and 1, indicating the probability of win (or the expected score). Then the assessed move's expected points score is similarly compared to the engine's top choice.

**Chess.com**: Using Chess.com's Knowledge Base, the current documentation for How are moves classified? What is a ‘Blunder’ or ‘Brilliant’ and etc? shows moves are classified using a new system, **ClassificationV2**, which uses an expected points model instead of the previous strict evaluation differences.

Chess.com is using the probability of a win evaluation and assessing the move's impact on that probability based on the following:

* Best: 0 ≤ change ≤ 0
* Excellent: 0 \< change ≤ 0.02
* Good: 0.02 \< change ≤ 0.05
* Inaccuracy: 0.05 \< change ≤ 0.10
* Mistake: 0.10 \< change ≤ 0.20
* Blunder: 0.20 \< change ≤ 1.00

Chess.com labels a move as "brilliant" (!!) when it sacrifices a piece, is best or nearly best move in the position, does not result in you having a bad position, and where you would not be completely winning if you had not found the move. This is defined more generously for lower rated players and stricter for higher rated players.

**Lichess.org**: The documentation for Lichess indicates that they also use their Win% and Accuracy% metrics "*to identify inaccuracies/mistakes/blunders in game analysis*."

Lichess definitions:

* "`Accuracy%` represents how much you deviated from the best moves, i.e. how much your winning chances decreased with each move you made."
* "`Win%` represents your chances of winning the game from a given position."

Lichess first computes `Win% = 50 + 50 * (2 / (1 + exp(-0.00368208 * centipawns)) - 1)`
which allows comparing `Win%` before and after each move.

This enables the `Accuracy%` calculation.
`Accuracy% = 103.1668 * Math.exp(-0.04354 * (winPercentBefore - winPercentAfter)) - 3.1669`

Older Lichess forum posts (, ) indicate previous strict evaluation differences such as

* Inaccuracy: 0.5 \< gap ≤ 1,
* Mistake: 1 \< gap ≤ 2, and
* Blunder: 2 \< gap,

may have been previously used, but it seems this is no longer the case.
> 6 votes

---
Tags: engines, stockfish, online-chess, computer-chess, annotation
---


# Question
Title: Youngest Player to beat a reigning World Champion?
In September 2022 19 year old Hans Niemann beat Magnus Carlsen in the Sinquefield Cup.

On the 19th January 2023 18 year old Nodirbek Abdusattorov beat Magnus Carlsen in the Tata Steel tournament.

Is Abdusattorov the youngest player to beat a reigning world champion in a classical (i.e. not rapid or blitz) over-the-board game?

# Answer
I have not identified the record with certainty, but here are some young winners of World Champions in classical chess:

* N.Abdusattorov, 18y 4m 1d, vs Carlsen in Wijk aan Zee 2023
* V.Kramnik, 18y 8m 11d, vs Kasparov in Linares 1994.
* A.Esipenko, 18y 9m 17d, vs Carlsen in Wijk aan Zee 2021
* T.Radjabov, 18y 11m 10d, vs Topalov in Linares 2006

*Edit*: V.Keymer, winning against World #1 at 18y, 9m, 25d, would be in a very good spot on this list, had Magnus Carlsen not renounced his World Champion title a few months earlier...
> 18 votes

---
Tags: records, world-championship
---


# Question
Title: Rook and promoted Bishop vs Rook endgame--forced win or draw?
I've recently been trying to learn the queen vs rook and rook and bishop vs rook endgames, and I've found it interesting how close the margin of victory vs draw is. I was thinking about whether the bishop's color lock is the reason it can't win. So what if we gave the bishop its shogi promotion that allows it to additionally move like a king? Does this promoted bishop give its rook the support it needs to overcome the enemy rook?

Also, as a related question, is there a more general resource for analyzing endgames with nonstandard pieces?

# Answer
It's hard to provide full analysis, but I'd say yes with almost all certainty. One of the main difficulties the stronger side encounters on this endgame is getting to use the bishops to block checks on the right squares. This leveled-up bishop can block checks on any square while the king and rook corner the enemy king
> 1 votes

---
Tags: endgame, checkmate, unorthodox-pieces
---


# Question
Title: What is the variability of engine evaluations as a function of depth?
Chess engines such as StockFish provide centi-pawn evaluation of positions. Clearly the longer the engine runs the deeper it can search and thus provide more accurate centi-pawn evaluation.

Basically, given a random position (say of equal material), I seek to know how the centipawn evaluation changes as a function of the depth parameter. When the depth is very low (say 2-5 moves) the evaluations expected to be erratic and change dramatically, but how does it look like on higher depth (say 20-30 or even higher) - do we tend to see convergence to a value? In other words, is it the case that we learn less and less about the position the deeper we go?

Interestingly, in both cases having the engine run long enough is somewhat futile (unless we are looking for a forcing mate), for (1) if depth 30 is good enough and we learn less and less the deeper we go, why bother to reach depth 40? Or (2) if the other case is true: namely, that there could be some significant difference between depth 30 and depth 40 evaluation, why stop at 40? who promise us that at depth 50 the evaluation would be closer to the 40 value than of the 30?

# Answer
> 1 votes
**Not possible to predict**

An extra node (i.e., position searched) can always change the evaluation, potentially by a lot. Regardless of how far ahead you search, as long as you don't search the entire game tree (not realistic for chess), it's always possible there is something just "beyond the horizon" that you didn't find.

See example here. When going from d = 28 to d = 29, Stockfish's evaluation crashed ("moobed" in the lingo of engine chess enthusiasts). That's because it missed a tactic that required d = 29 to find.

You can find more examples of such positions where the engine's eval changes dramatically after a certain period of thinking time here.

---
Tags: engines
---


title: "Safe advantage" and "unsafe advantage"

text:
# Question
Title: "Safe advantage" and "unsafe advantage"
By a safe advantage, I mean it is easy for the side with the advantage to keep it. Winning the game is extremely likely under normal conditions. Example: KQ vs KN is a very safe advantage.

By an unsafe advantage, I mean it is a complicated position and the side with the advantage can only keep it with very accurate play. If they make even one mistake/inaccurate move, the advantage may be lost and they may even lose the game. Many complicated middle game positions are "unsafe" in this sense.

Does there exist terminologies that describe a "safe advantage" and "unsafe advantage"? Can an engine give a "safety index" of an advantage?

# Answer
What you are looking for is the term "sharp". A position that is sharp requires accurate play to maintain the evaluation; there may only be one good move for either side. From there defining this sharpness is hard to do from a first principles basis as what is sharp for you or I may not be for Magnus. That aside here is a free tool you may want to play with. The fritz engine also claims to have its own sharpness evaluator.
> 4 votes

---
Tags: engines, terminology
---


# Question
Title: What is the reasoning behind the suggested move?
In this game, my actual move was Qg6, leaving the knight on f3.

Why does chess.com suggest Ne1+ ?

I figure it would just be taken by the rook, but the engine suggested white would have played Kf1.

The text says this will win the white queen. I don't get it.

# Answer
> 4 votes
The idea of 1...Ne1 is to distract the Rook from the defense of h2, so the Black Queen would go to h2. For example:

If 2.Rxe1 Rxf2 check ***(attraction)*** 3.Kxf2 Qh2 check 4.Kf1 Rf8 check 5.Qf7 Rxf7 checkmate.

In addition, if 2.Kf1 Qxe3, with the idea of 3... Qxf2 checkmate.

If White would not capture the Knight, Black has brought that Knight to the attack, and the h3 square is free for the Black Queen. For example:

If 2.Kg1 Qh3 with the idea of Qg2 checkmate.

# Answer
> 1 votes
The other answer covers everything but I'll add that what engine analysis says about a totally winning position doesn't matter much. Here Stockfish can see the mate in 5, so it goes for that. If you can't, you'll just play some simpler move and your position will still be winning.

Also, if you don't understand an engine's suggestion (like Kf1 instead of Rxe1), you can play the move you think is better and see how the engine reacts to it.

---
Tags: analysis, tactics
---


# Question
Title: FIDE rules regarding use of foreign languages in algebraic notation
Article 8.1a states that:

> In the course of play each player is required to record his own moves and those of his opponent in the correct manner, move after move, as clearly and legibly as possible, in the algebraic notation (Appendix C), on the ‘scoresheet’ prescribed for the competition.

Appendices C2 and C3 state:

> C.2 Each piece is indicated by an abbreviation. In the English language it is the first letter, a capital letter, of its name. Example: K=king, Q=queen, R=rook, B=bishop, N=knight. (N is used for a knight, in order to avoid ambiguity.)
> C.3 For the abbreviation of the name of the pieces, each player is free to use the name which is commonly used in his country. Examples: F = fou (French for bishop), L = loper (Dutch for bishop). In printed periodicals, the use of figurines recommended.

Hence foreign languages and, indeed, foreign alphabets are allowed in the part of the notation denoting the piece moved. I believe I've seen Greek letters for pieces in a top level scoresheet.

However, C5 states:

> The eight files (from left to right for White and from right to left for Black) are indicated by the small letters, a, b, c, d, e, f, g and h, respectively.

C7 goes on to state:

> As a consequence of the previous rules, each of the sixty-four squares is invariably indicated by a unique combination of a letter and a number.

and then goes on to give a picture of a chessboard with the squares annotated with a1 through h8.

No allowance is made here for use of foreign alphabets and indeed in the aforementioned scoresheet that I saw the letters a through h were used for the files.

Am I correct in believing that the effect of these rules is that while native Russian, Greek, Arabic, Hebrew, Thai, Hindi, etc. speakers may use the standard abbreviations for the pieces in their own alphabets they must use the Latin letters a through h for the files rather than, for instance, alpha, beta, gamma, delta etc. for a Greek person?

# Answer
> 2 votes
There was an International Arbiter at our club annual rapid championship last night and when I asked him this question he was rather dismissive, I'm afraid. The rule is not intended to discriminate against speakers of languages with non-Latin alphabets and of course they may also use their alphabet for the files.

# Answer
> 8 votes
As a native Russian player I may assure you that we always used the suggested notation, e.g. Фd4 or Лd1 (Ф - ферзь - for Queen, Л - ладья - for Rook, etc); even the 6 years old beginners did so. Nobody ever was insane enough to suggest Russian alphabet for encoding files.

# Answer
> 1 votes
Russian algebraic notation uses Roman letters a-h. Hebrew does use א (Aleph) through ח (Ḥet, the 8th letter). It would be awkward to mix Hebrew letters, normally read right-to-left, with Roman, read left-to-right (as is Cyrillic). Yes, the Aleph column is still on the left, even though this makes columns a-to-h appear as א-to-ח in most diagrams, reversing the usual reading order. (In actual play White sees the columns in reverse order, but Black sees them in natural order -- so on average it's a wash.)

---
Tags: fide, annotation
---


# Question
Title: Is Whale Variation a successful opening?
I am an early, intermediate in chess. I played the Whale Variation (1.e4 e5 2.c4) and won some games as White. But there is an issue when Black moves their knight to d4. I have a problem with it. Is the Whale Variation a proper opening to use?

I would like to know your ideas about Whale Variation.

# Answer
> 4 votes
The Whale variation

```
[FEN ""]
1.e4 e5 2. c4

```

is quite an offbeat opening. It shares obvious similarities with the English opening, and it sometimes transposes, but it has some serious drawbacks. The obvious one is the gaping hole it leaves on `d4`. Another one is that it leads to very closed positions, which intermediate players usually do not fin comfortable. This leads to inaccurate plans and rushing, which because of the dubious setup from white, usually ends up favoring black. The main one is that white does not have a threat, allowing black to immediately seize the initiative with `Nf6`.

Let's address first the hole on `d4`. There are several setups to play around it, the most straightforward plan is to play `d3`, `Be3`, and `Ne2`. This overprotects the weakness and ensures better center control, but is awfully slow since `Bc5` essentially blocks everything, and severely neglects king safety (white's not gonna castle anytime soon). Another setup is to kingside fianchetto, and another is with `Be2`. They all have big drawbacks, since essentially white is playing an English opening with a way too early `e4` push. With somewhat accurate play for black (`Nf6` and `Bc5`, which are natural moves that they should consider), there really is no good solution for this.

Here you have several sample lines that give an idea of why this opening should be avoided. For example, 1. e4 e5 2. c4 Nf6 3. Nc3 Bc5 4. d3 d6 is more than fine for black, with easy plans and development. This seems like a closed Sicilian gone wrong. Also, 1. e4 e5 2. c4 Nf6 3. d3 Bc5 4. Be2 is pitiful, with white's only "developed" piece being completely shut behind the pawns. Black still has easy plans.

Finally, let's address the issue of giving up the initiative. Since white is no making any threats with 2.c4, black is completely free to just play `Nf6` and `Bc5` in virtually all variations. Moreover, `d6` and `Bg4` is a very standard plan, as well as `Nc6` aiming for the hole in `d4`. Since the dark squared bishop is now outside the chain pawn, black has `e7` free for a knight, with Nf6-Ne7-Ng6 being a common reroute.

This makes it a difficult variation to play if black makes reasonable moves. I would suggest to play the English opening, and steer the game into closed positions that will benefit from a timely `e4` push. For example: 1. c4 c5 2. Nc3 Nc6 3. g3 g6 4. Bg2 Bg7 5. Nf3 Nf6 6. e4, followed by `d3`.

# Answer
> 0 votes
I really like it and have used it for a while. The biggest problem for me though is the complete lack of white bishop movement. I played like this https://www.chess.com/game/live/68154946291

---
Tags: opening, analysis, learning
---


title: Why is this the wrong move?

text:
# Question
Title: Why is this the wrong move?
I am new to chess. I am playing puzzles on chess.com. I made a move which I thought was checkmate, but it tells me I made the wrong move.

It looks to me like the King is in check by the bishop. But no pieces can take the bishop, and the king has no safe spaces to move to.

Why is this the wrong move?

# Answer
> 4 votes
I just realized, the knight cannot take the bishop, but it can block it!

# Answer
> 6 votes
White can play Ne2 and block the check. Instead, you can play Rd2 which is mate in one.

---
Tags: checkmate, beginner, chess.com
---


# Question
Title: Stockfish destroys Daniel Naroditsky's endgame variation (from his book (Mastering Positional Chess))
```
[FEN "7r/p3k3/2p5/1pPp4/3P4/PP4P1/3P1PB1/2K5 w - - 0 1"]

1. Kd1 Rh2 2. Ke1 Rxg2 3. Kf1 Rh2 4. Kg1 Rh6 5. f3 Re6 6. Kf2 Kf6 7. Kf1 Kf5 8. Kf2 b4 9. a4 Re4 $4 *

```

The position and variation was taken from Mastering the Positional Chess by Daniel Naroditsky, Chapter 3, Page no. 95.

Stockfish says starting position is losing. That's what Daniel also wrote in that book. But later he clarified the position is drawn. In his book, he marked Ke1 as brilliant move whereas chess.com mark it as inaccuracy. Even no player between 1000-2000 will ever play Re4. Even after Re4 it is winning for white.

```
[Event "?"]
[Site "?"]
[Date "????.??.??"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "*"]
[SetUp "1"]
[FEN "7r/p3k3/2p5/1pPp4/3P4/PP4P1/3P1PB1/2K5 w - - 0 1"]

1. Kd1 Rh2 2. Ke1 Rxg2 3. Kf1 Rh2 4. Kg1 Rh6 5. f3 Re6 6. Kf2 Kf6 7. Kf1 Kf5 8.
Kf2 b4 9. a4 Re4 10. fxe4+ Kxe4 11. Kg2 Kd3 12. g4 Kc2 13. g5 Kxb3 14. g6 Ka3
15. g7 b3 16. g8=Q b2 17. Qg6 Ka2 18. Kf3 b1=Q 19. Qxb1+ Kxb1 20. Kf4 Kc2 {No
matter which way black king will go he is always slow. Whereas the variation in
Naroditsky's book ended after b2. {he didn't continue the variation anymore\}}
(20... Ka2 21. Ke5 Ka3 22. Kd6 Kxa4 23. Kxc6 Kb4 24. Kd6 a5 25. c6 a4 26. c7 a3
27. c8=Q a2 28. Qb7+ Ka3 29. Qa6+ Kb2 30. Kxd5 a1=Q 31. Qxa1+) 21. Ke5 Kxd2 22.
Kd6 Kd3 23. Kxc6 Kxd4 24. Kb5 Ke4 25. c6 d4 26. c7 d3 27. c8=Q d2 *

```

In the above variations, Daniel stopped his variation after b2. And black can play some waiting move but white's king will aim for others pawn whereas the queen will guard the b1 square forever. As played out the moves on board, I noticed black's king is slower than white's king to grabs pawns. So no matter where the black's king aims for he is likely to be lost. I didn't see any drawing chances.

How the position before Re4 is draw? Even how is it likely to be draw after Re4?

# Answer
> 20 votes
I think you misunderstood both the position and Naroditsky's comments.

> Stockfish says starting position is losing.

The point of the study, as often, is that the correct evaluation goes against your first intuition. Here Stockfish is confused by the huge material advantage Black can gain and typically fails to assess correctly that White can build a fortress and save the draw.

The credit for this gem goes of course to the study's creative author, Vitaly Chekhover, not to Naroditsky.

> That's what Daniel also wrote in that book.

Daniel Naroditsky did **not** write that White is losing. He wrote *"At first sight, White is completely lost"* which hints that there is more to be found than what's on the surface and stresses out how miraculous the saving idea will be.

> If black doesn't play Re4 then white is likely to out of moves sooner (will be in zugzwang.)

That's not correct. White has the waiting moves Kf1-f2-f1 when the black rook is on the e-file and Kg1-g2-g1 if it switches to the h-file. Thus White will never be in zugzwang and can patiently hold in his fortress. Whatever the evaluation of your engine, this position is a draw.

> After Re4 it is winning for white.

Even if it's true it won't change Naroditsky's point: with or without ...Re4, Black cannot win.

> Didn't Daniel calculate other variations while analyzing this position (I am not asking if he had really did. But I am asking why didn't he show other variations as he did for other examples)?

The position after 9.a4 is a positional draw where there is no *variation* to be checked at all: ...a6 or ...a5 or king moves are pointless, the white King can deny any entry square from the black Rook, so Naroditsky analysed 9...Re4 because targetting d4 is basically the only attempt to disturb the balance.

The reader is expected to check by himself that "Black has no way to break through", you can try to shuffle the rook a bit to convince yourself, but no extra variation can help you reaching that conclusion. He could have given a line like 9...Rh6 10.Kg2 Kf6 11.Kg1 Ke7 11.Kg2 a6 12.Kg1 Re6 13.Kf1 a5 14.Kf2 Kd7 15.Kf1 Re8 16.Kf2 and so on ad nauseam, but that would not have been much more informative.

---
Tags: endgame, books
---


# Question
Title: When should white push d4-d5 in the Ruy Lopez?
I just played a very short game in the Ruy Lopez, where I played white and pushed d4-d5 early, and it felt like I just gave black's knight a headstart to maneuvre into a better position where I was quickly lost. I thought that this push was common in Ruy Lopez positions so I was surprised this was so bad, and I can't find any master games in a similar position where this mistake is made (and it makes sense that I just helped black with their maneuvre), so why then is it so clearly bad here, but apparently thematic in other Ruy Lopez positions?

```
[Event "Live Chess"]
[Site "Chess.com"]
[Date "2023.01.24"]
[Round "-"]
[White "me"]
[Black "black"]
[Result "0-1"]
[CurrentPosition "r4rk1/ppp3pp/1b1p1pn1/3Pp3/4Pn2/2P1BN1q/PPBN1P2/R2QR1K1 w - -"]
[Timezone "UTC"]
[ECO "C64"]
[ECOUrl "https://www.chess.com/openings/Ruy-Lopez-Opening-Classical-Central-Variation-Charousek-Variation"]
[UTCDate "2023.01.24"]
[FEN ""]
[UTCTime "07:21:29"]
[WhiteElo "1714"]
[BlackElo "1827"]
[TimeControl "600"]
[Termination "Black won by resignation"]
[StartTime "07:21:29"]
[EndDate "2023.01.24"]
[EndTime "07:26:39"]

1. e4 e5 2. Nf3 Nc6 3. Bb5 Bc5 4. c3 Bb6 5. O-O d6 6. Re1 Nf6 7. d4 O-O 8. d5 Ne7 9. Bd3 Ng6 10. h3 Nh5 11. Bg5
f6 12. Bc1 Nhf4 13. Bc2 Bd7 14. Be3 Qc8 15. Nbd2 Bxh3 16. gxh3 Qxh3 0-1

```

# Answer
Obviously d4-d5 in your game was not successful even if you could have defended better afterwards (e.g. 11.Be3 comes to mind, to counter the beast bishop on b6).

d4-d5 is a double edge move, gaining space but removing the pressure against e5 and the possibility to open the d-file. Many strategic subtelties and tactical nuances can make it better or worse given the circumstances.

Factors than make d5 more attractive are:

* White first plan in the Ruy Lopez is to target the Pe5 and force Black to protect it. Most often you want to wait for Back to invest time in the defense of e5 (...Re8, ...d6, sometimes Nc6-b8-d7...), or to threaten ed4 (e.g. with Nf6, Re8, Bb7 aiming at e4) before you release the pressure with d4-d5 and leave their pieces passive.
* when Black has played ...a6 and ...b5, the square c6 is weakened and d5 puts a grip on it. Also, the Black queenside pawns are a target (exposed by a4 or b3-a4 or b3-c4) which will be more difficult for Black to defend when the Pd5 restricts their pieces.
* if the dark squared bishop is inside its pawn chain (Be7), then d5 blocking the Pd6 will box it in and force it to remain passive for a long while (Black sometimes go for the very long plan ...Re8, ...Bf8, ...g6, ...Bg7 and eventually ...f5 to revive it). Conversively, when it eyes f2 from a7 or b6 as in your game, d4-d5 opens a dangerous diagonal where the active bishop sits very happily.
* Black's light-squared sometimes goes to b7, trying to target White's Pe4. It would enjoy a bright future if the center opens, but d4-d5 shuts the door on its nose; ...c7-c6 would then be the only try to revive it, but it's not so easy to engineer because it weakens the Pd6 and the square d5.
> 2 votes

---
Tags: pawns, ruy-lopez
---


# Question
Title: Have there been GMs playing consistently super-risky?
Three things I don't mean with super-risky:

* Tal was a risky player but he could calculate extremely well and had reasons to believe that if a refutation of his sacrifices exist, the opponent wouldn't find it (only today's engines).
* In a lost position anything is fair game, so no point of thinking about the objective centipawn value of a move.
* In rapid games you can risk far more anyway.

I thus define a super-risky move as a trap in about equal position in a tournament game that can be seen through by the average opponent (say, GM level) and ends up to the disadvantage of the trapper. (That's surely not 100% objective but shall suffice.)

Have there ever be any GMs (especially including GM-strength players before the title existed) playing consistently super-risky? (I throw at least one suggestion into the room: Dawid Janowski.)

# Answer
What you describe is called "Hope chess". It is a very common beginner's mistake. To reach any reasonable standard of chess (like strong local club player) the player has to eliminate this basic mistake. So, no, master level players do not do this. If they play a move which looks like this then it was a blunder rather than a deliberate bad move.
> 6 votes

# Answer
Hans Niemann, in his post-Sinquefield Cup interview (the end of his first super tournament) described himself on the opposite end of risk-taking compared to Wesley So, who is very risk-averse. Hans then says for future tournaments he needs to be more risk-averse, and that playing risky is influenced by playing lower rated players but causes unnecessary losses at the highest level.
> 4 votes

# Answer
Is this close even if no cigar? I think of Carlsen in openings.

Larry Kaufman says:

> 'Magnus doesn't generally play such great openings, he strives to get the game out of book as early as possible usually.'.

Of course, it's not always that an out of book move is far inferior to a book move.
> 0 votes

---
Tags: style
---


title: Early recorded games (before 1600)

text:
# Question
Title: Early recorded games (before 1600)
Do we have examples of recorded chess games from 1600 or before? A game where all the moves were written down. It would be interesting to see such a record.

This question was inspired by Was not chess notation an earlier sort of Cartesian Coordinates? on History of Science and Mathematics Stack Exchange. (There it is asked whether chess notation may have influenced Descartes' coordinate system work; but that is not my question here.)

# Answer
Here is a list of such games at chessgames.com.

Of course, you can't blindly copy them; the oldest one is a fictional game from a poem and some aren't complete games. But it should give you a start ...
> 5 votes

# Answer
Besides Murray's History of Chess (already referenced), you may also try:

The Oxford Encyclopedia of Chess Games (by Levy and O'Connell) tried to reproduce all known chess games before ... was it 1800? As it was intended for modern readers, it uses modern notation, but most scores have a source reference, which you might be able to trace -- though I suspect many go to Murray's manuscript notes. (Don't rely on its index, though.)

It is also a question of how you define 'chess' and 'game'. You might be defining it in a way that limits your inquiry already from the start. Several early manuscripts on chess problems have 'notation' but not for complete games. You can find the Bonus Socius collection in Murray, for example, (also in van der Linde) and there's at least one modern reproduction of the original manuscript, in case you want to go at that level. But you should have at least some facility for reading medieval latin or french for that.

And I'm sure there are Arabian manuscripts as well, though those are outside my sphere of interest.
> 1 votes

---
Tags: history, notation, famous-games
---


# Question
Title: Do serious chess players ever play time-controls without increments?
Do serious chess players ever play time-controls without increments?

Not necessarily limiting to GMs but let's say professionals or "amateur-professionals".

# Answer
Around here matches between the local counties (Chiltern League, UK) still have a guillotined time limit of 2 hours each for all moves. All other competitions I play in have increments; in fact I won't nowadays play in a competition unless it has an increment, Chiltern League excepted, though I can't actually remember when this was last an issue.

Whether you count me as "serious" is another matter ( 1932 ECF, play about 50 rated games a year), but in our last Chiltern League match there was an IM and two FMs playing, along with a few other 2100+ players.
> 1 votes

# Answer
The most recent tournament I played, the Grenke Open 2019, had a time control of 2 hours for 40 moves and 30 minutes for the rest of the game, no increment. Considering the number of 2600 players in that tournament, I would be inclined to answer yes.

Since then there hasn't been another Grenke Open, so that answer is a bit old but I doubt they would add increment. I think with a very large tournament and two rounds per day it might otherwise be difficult to schedule. (at least with the usual 30 seconds per move increment)
> 1 votes

# Answer
Classical Tournaments basically all have increment, or at least delay.
> 0 votes

# Answer
In the past it wasn't that easy to get a clock with increment per move, so non-increment games were the norm. The most similar thing you'd get is extra time controls (like 30 or 60 extra minutes after move 40).

Today almost all chess clock used in competition allow you to set time increment so the technichal limitation isn't there anymore.

Competitive non-increment games require extra rules and more arbiter intervention, so when given the option, organizers will usually choose to set an increment even in Blitz tournaments
> 0 votes

---
Tags: time-control
---


# Question
Title: What are all of the possible tags for PGN?
In a PGN file, there are tags like:

```
[Event "Tournament"]
[White "John Smith"]

```

And so on. I would like to know all the possible tags for PGN files so I can use them in a PGN file that my friend is demanding for.

# Answer
> 9 votes
PGN standards are described here. There are seven more-or-less required tags:

```
[Event]
[Site]
[Date]
[Round]
[White]
[Black]
[Result]

```

and many different supplemental tags, for example `[WhiteElo]` and `[BlackElo]` for the players' ratings, `[Board]` for the board number in team events, and `[TimeControl]` for information about the time-control used.

# Answer
> 4 votes
Glorfindel cited the PGN standard, so if you feel you need to include fields that you're not familiar with, by all means consult it.

But like *many* standards, it's far too comprehensive to be implemented fully in most situations. For example, the standard provides for the \[Date\] of the game, and the \[EventDate\] of the tournament; both White's and Black's clock time at the end of the game; the 3-letter acronym for the player's country, the name of the player's team (in an Olympiad or World Team Championship, these will match, but otherwise the team is normally unrelated); the name of the source publication for the game, the \[SourceDate\] for the date of the publication that the game appeared in; the *Site* and the *EventSite*; ... you get the idea.

Way over the top for all but the professionals, primarily those involved in publishing tournament bulletins and chess e-/magazines.

I'd also encourage you to make sure your PGN fields include:

\[Event\] \[Date\] \[White\] \[Black\] \[Result\]

Of the seven mentioned, the following are optional, even in published games: \[Site\] \[Round\]

The Site can be multiple things: the city name, such "Baku", the server organization name (if online) such as "playchess.com", the correspondence chess association (if CC) such as "ICCF", or the tournament name, such as "Dos Hermanas".

The Round is used when there are multiple games in one event, as in most tournaments, but can also be a combination of Board # *and* Round # in team tournaments. So, in the Baku Olympiad, for example, "Round 1.1" signifies a game played on Board 1 in Round 1. In most older tournament scores, the Round information is often missing, although it could be reconstructed from the tournament crosstable.

Note that \[Event\] *must* be the first field for most PGN import processing.

If the game score doesn't begin from the start position, you can insert a FEN field to represent the position, who's on move, what castling rights remain, and any e.p. capture that is possible at the beginning position. Just look up Forsyth-Edwards Notation for more information.

Use spaces to separate the moves and move numbers as follows:

9. \[white move\] \[black move\] 10. etc.

You may run into trouble with variations, if you transcribe them manually. Keep the following rules in mind.

A. The variation immediately follows the move that it varies from, so:

4. e5 dxe5 (4... d5)

shows the alternative move 4...d5 in the proper position in the score, immediately following the main (or parent-variation) move.

B. Certain codes are used by some PGN translators to represent the position evaluations at the end of a variation. They don't always import and export them the same way, and they don't always accept the "+/-" Informator symbology.

C. The game score should end with the result. e.g. "1-0", or "\*" if it is only a line.

D. The FEN diagram / game replayer used on Chess.StackExchange is non-conforming, so don't use your experience with it as a guide. Two examples:

* It doesn't require the \[Event\] field at all
* It requires all PGN information lines to have a 4-space prefix. The latter helps distinguish the games from the language of the rest of the post on C.SE; such text outside of a game is not an option in the PGN standard.

# Answer
> 1 votes
PGN specification makes differences between import and output formats. For example, the seven tags event, site, date, round, white, black, result are mandatory for output in a specific order, but when importing you shouldn't be that strict - missing tags are ok, other order is ok, etc.

Then, there are a number of frequently used additional tags, like tags for rating, opening, title, etc. Open some of your favourite PGN files in an editor and have a look.

Then, when importing, I'd more or less accept *anything* that looks like a "key-value-pair" tag, and ignore (but maybe store) it if it's unknown.

I don't think most chess software give perfect PGN output, but most of them will also accept rather "exotic" interpretations. What does this mean for your use-case? Ask yourself what games you want to transfer, what info is in there, and then you'll probably find good tags for that. Maybe consider how your friend is going to process the PGN files.

# Answer
> 0 votes
I just have seen that old question, and I think I have a new (more complete) answer to it.

The PGN specification of course is the reference, because of its old state, I decided to have it published in a new fashion. See my GitHub repository on PGN Spec Commented for that. The following links are all linking to that repository:

* PGN Spec Chapter 8.1 about the tag pairs. It explains in detail the so called seven rooster tags.
* PGN Spec Chapter 9 which contains the so called supplemental tag names.
* PGN Spec Supplement 5 the running clock. So if you want to stream a game, you may deliver the current clock as that.
* PGN Spec Supplement 6 the clock start time. Allows to have additional information, if you want to show a game that has different start times for the players (e.g. because the game is in the middle).

So I have no idea if these additional tags are used at all, but they are at least described.

---
Tags: pgn
---


# Question
Title: Iuri Shkuro is part of the top peak FIDE blitz rating list (2800+) apparently by 'farming'
There's a Sep2020 reddit post by user ChessAddiction entitled 'How the Elo rating system works, and why "farming" lower rated players is not cheating.' I also ask about farming here: When is farming unethical?

NoseKnowsAll asked here

> Who the heck is Iuri Shkuro and how did he get such a high blitz rating if I've never even heard of him?

This is re the entry

> Shkuro, Iuri Ukraine 2828 2017/03

I googled this and apparently Iuri Shkuro is a Ukrainian GM who was involved in some kind of 'farming' in blitz rating. This post is kinda TL;DR. (I tried scanning for instances of 'farm' or anything similar but couldn't find.) NoseKnowsAll actually shares a link to a FIDE webpage re Shkuro, but I still don't see any indication of 'farm' in the page.

# **Question**:

**What was going on**:

1. What did Iuri Shkuro do, and
2. what was wrong with what was done?

Sounds like the guy was playing in tournaments meant (mainly but not only) for 1500-1999 players or something. I mean, **if farming 'is not cheating', then why doesn't this apply to Shkuro**? Based on another post, it doesn't seem like farming is 'unethical' just 'risky'.

> No GM would risk a hefty rating penalty by playing only weak tournaments. Too much risk for very little gains. A single tactical oversight (GM is human too!!) could be deadly.

# Answer
> 1 votes
Got an answer from kitikami from reddit in a post that compares Shkuro with Igors Rausis.

cf Why is there a minimum rating gain when you win?

It appears Shkuro was **making tournaments** where e'd obviously win where as Rausis was just entering tournaments, **of other people**, where e's most likely win.

---

1

> Rausis was entering weak open tournaments that no normal GM would have any interest in and beating amateurs in a handful of classical games, but they at least appeared to be legitimate tournaments.

2

> Shkuro and Kobylianskyi were organizing and directing their own blitz or rapid tournaments where they would play a bunch of random locals over a day or two and then submit their results to FIDE until it pushed them into the top 10 of the World Blitz/Rapid lists. I think there were even some questions about whether they were playing the events at all due to how obscure, poorly organized, and poorly documented they were, but in any case these events had no discernible purpose other than to inflate the rating of the person organizing the event and did not appear to ever have been presented as a serious competition. FIDE's decision to nullify their ratings was as simple as making all these events unrated (which would not have worked for Rausis since other than him farming, the results of those events had legitimate competitive meaning).

3

> Rausis' rating was arguably no more legitimate (and his farming was arguably even less ethical since he was ruining real tournaments for his opponents rather than doing his own vanity thing separately), and you could certainly argue his rating deserved to be handled the same way as the other two. What he was doing was on a smaller scale and exploiting existing tournaments available to anyone, though, whereas the other two appeared to be deliberately manufacturing their own personal rating farms.

4

> Here's a record of a rapid tournament where Kobylianskyi is listed as both Tournament Director and Chief Arbiter and scored 10/10 and a blitz tournament where Shkuro is listed as Tournament Director and scored 33/34.

5

> FIDE's official decision is here: https://doc.fide.com/docs/DOC/2021%20GA/Annex%203.2.1c%20UKRAINIAN%20PLAYERS.%20Final%20Resolutions.pdf

6

> The tournaments were originally rated, but FIDE decided after their investigation to rescind the ratings from all their tournaments within the suspicious time periods. While the investigation was ongoing, it looks like FIDE put them both under a sort of probationary period where the Ukrainian Chess Federation had to get FIDE approval for them enter any rated events, but after FIDE released their decision they were free to enter events as normal again.
>
> It looks like the only thing that happened was FIDE reset their ratings and basically told everyone "don't do this again".

# Answer
> 3 votes
https://www.fide.com/news/344

Looks like he is under investigation and under suspicions of cheating. His actual rating has not changed either...

---
Tags: rules, fide, rating, online-chess, etiquette
---


# Question
Title: Why wouldn't Magnus Carlsen just farm rating points by playing weak tournaments to reach 2900 kinda like what Igors Rausis did?
**Edit re close votes for opinion-based**:

1. I edited question from don't/didn't to wouldn't. So now it's hypothetical for any player who happens to to have a peak rating of 2800+.
2. Voting this to be opinion-based kinda assumes it IS optimal. Explain then why it is optimal please?

---

Maybe related:

1. Why is there a minimum rating gain when you win?
2. Iuri Shkuro is part of the top peak FIDE blitz rating list (2800+) apparently by 'farming'
3.

> Seems like the minimum guaranteed gain for any win does make farming profitable.Vladimir F Героям слава

4. What stops me from pumping up my rating by playing a 200 game match against a much weaker (\>400 point difference) player?
5. Could you raise your score arbitarily high by only playing against much weaker opponents?

---

Note 1: I think I read but am not sure: FIDE has, or HAD, a rule like even if you're more than 400 points apart from your opponent, the game is treated as if you're just 400 apart. Eg a 2600 who beats a 1600 gains the same rating as beating a 2200. But I heard FIDE made a change to this rule. In any case, I'm gonna ask my question pretending the rule is still in place.

---

My question is:

> In late 2021 / early 2022, Magnus said e had this goal to reach 2900+ peak FIDE rating (either in the monthly lists or live ratings if Magnus didn't already), why doesn't Magnus Carlsen just farm rating points by playing weak tournaments to reach 2900 like what Igors Rausis did?

Now, I saw some posts that say it's optimal but unethical or ridiculous while others that say it's not optimal. Hence, this question boils down to whether or not it is indeed optimal.

Case 1: It is optimal.

* Here my question becomes: **So, why wouldn't Magnus, or any 2800+ player really, do it?** I mean, is it because Magnus is afraid that the achievement will not seem 'legitimate'?
* Note 2: This is kinda arguing ex post facto, but I don't think 'because regular tournaments mean more money for Magnus' is an answer given how Magnus quit the 2023 WCC later in mid-2022.

Case 2: It is not optimal.

* Here my question becomes: **Why is it not optimal?**

# Answer
> 1 votes
"Farming" was indeed the optimal stratregy to climb the Elo ladder. The reason Carlsen (and most top players) don't use it is simple: gaining rating points is not the ultimate goal of his chess career. The actual goal is winning important tournaments. Rating is the way to get access to those tournaments, but at this point in his career no tournament in the world would deny Carlsen a chance to enter because of his rating being too low.

Since the regulation changes from late 2022 it's no longer possible to just farm weaker opponents. The 400-point gap rule applies now to one game per month rather than to every game played like it used to.

Before the changes, only Carlsen himself knows the reason. However if he reached 2900 by climbing like that, the damage to his reputation would be much bigger than the reward he could get by hitting 2900.

There's also a cost of oppotunity: he would permanently lose the chance to break that record in the proper way. And also winning 50+ classical time control games is a huge time investment that Carlsen could be using for anything else.

---
Tags: fide, rating, etiquette, carlsen
---


# Question
Title: How many positions per second should my homemade engine calculate?
My program prints time spent on executing a function for doing/retracting move, and both take together an average of 00.0002 seconds. That means my engine can analyze at most 5000 positions per second, right? That doesn't seem to be good, given the branching factor of 30.

How bad is that, and what average/maximum speed could I expect with optimizations (on normal char\[64\] board) ?

# Answer
> 1 votes
On my old laptop with an i5 processor, running on a single thread, a recent version of Stockfish (written in CPP) makes around 1 million nodes per second (1Mnps). You must take into account that these nodes are not just the move generator, but the engine is also using its evaluation, so Stockfish's move generator should be much faster than that

My very simple chess engine (written in C), whose move generator is not optimized can make around 4.5Mnps also on a single thread (with no evaluation, just the move generator working. This is what in chess programming is called a perft test).

So at first glance something like some thousands of positions per second seems like very poor performance.

Of course part of this poor performance can be due to the language you've chosen to write your engine, but unless you've made a really weird choice, it seems like there's something odd about your program. My educated guess is either the move generator is buggy or its design is (very) sub-optimal.

# Answer
> 1 votes
I benchmarked my home made chess engine. It can play 600 000 moves per second in debug mode. It can calculate 80 000 - 100 000 legal moves per second in debug mode (which means that it can calculate and then play around 70 000 legal moves per second in debug mode). However, when running my engine in release mode it is over 10 times faster than in debug mode, meaning that in release mode it can calculate and then play 700 000 legal moves per second. I made my engine in Rust (if you wrote your engine in Python maybe that's why it is slow), I store the chess position by having an array of chess pieces that store their position. When calculating legal moves I first create another representation of the chessboard, this time I make an 8 by 8 array where every number represents a chess square (this way I can check whether a piece is in the way of another piece in O(1) time instead of in O(n) time).

---
Tags: engines
---


# Question
Title: Farming: Prevent reaching a certain rating without having beaten/drawn someone of that rating (up to a point of course)?
**Context:**

In other online games like csgo and valorant, it's extremely unlikely to reach a certain rank without having beaten (or drawn with) someone of that rank. I guess this is largely because you cannot choose your opponents.

The case is similar in OTB chess where you (usually) can't choose your opponent. So for people peak rated X between, say, 1400 and 2600, they've definitely beaten or drawn with someone with peak rating greater than X. Eg if my peak (FIDE or USCF or whatever) rating is 1488, then I've definitely beaten or drawn with someone whose peak rating is at least 1488.

In online chess like on chesscom and lichess, you can farm rating in choosing opponents lower than you but you wouldn't necessarily be able to compete with people your own rating. Farming is even much more feasible when you do it in a farmbitrage way for chess960 in lichess. It's like this:

1. Let's say I create a new account and after 400 games, I've been rated about 1326 - 1345 for the last 50 games playing people only rated between (-10,10) of my rating whom I get paired with in public challenges.
2. Also, I have a peak rating of about 1359.
3. Being told of the idea of farming, I'll now try private challenging players rated 1000-1149.
4. Eventually I get a new peak rating of 1360+. But wait let's try to continue farming.
5. Now I've even reached **peak 1580** and have my rating settle about 1537 - 1558 for the last 50 games.
6. The problem is if I ever go back to the (-10,10), then I'm screwed. I'm about 1537 - 1558, yet I didn't actually beat anyone rated 1500+. I'd be screwed against even a 1480.

**Question**:

What would be some problems if websites like lichess and chesscom were to do something like **preventing a user from reaching a rating of, say, 1351 unless they've beaten or drawn with someone already 1351+** (rating at the time of the game as opposed to peak rating. Or you can do peak rating if you want. Let's say at the time of the game) ?

I know it's kinda artificial, but here's how I imagine what could be the case:

1. Let's say I'm 1347 and the highest rating of a player I've beaten or drawn is 1352.
2. Now I'm playing against a 1346.
3. If I win, then I would normally get a +8. But since the most I've beaten is a 1352, then my rating increase for this game is limited to +5 only.
4. Thus, if I win, then my rating is just 1352.
5. As long as I keep playing players lower rated than me, I should not have a rating more than 1352.

Notes:

1. You can do peak rating instead of rating at the time of the game. Eg I haven't beaten someone rated 1351 at the time of the game, but I've beaten someone who was previously rated 1351 (but was eg 1337 at the time of the game).
2. Of course this has to be up until a certain point. In OTB FIDE ratings, Magnus Carlsen is peak 2882 but hasn't beaten or drawn with players rated 2852+...except vacuously because there are no such players. So I guess the maximum for this could be like 3000 or something.
3. It doesn't have to be exactly 1351 to be allowed to reach 1351. It could be that I need to have beaten / drawn with a 1301 to be allowed to reach 1351.
4. **Consider that if FIDE, csgo or valorant implemented such a rule, then virtually nothing would change.**

**Purpose**:

1. My purpose in this question and my recent farming / rating questions is not really to beat the system or whatever, but **to know if I've hit a plateau** s.t. I realise 'oh ok time to do more puzzles or study more endgames.' Like if I can reach a rating X without further studying, then why not? Otherwise, how else would I decide 'oh I need to study more' ?

**In games like csgo and valorant, I can know exactly this.** If after 100 games I haven't ranked up, then I'll be able to realise that if I want to rank up, then I'll have to practice a lot more.

2. I think also for like sub battles or something. If I'm doing a sub battle, then how would I know the rating of anyone who applies for my team is not obtained primarily by farming? Like there's no asterisk or anything that says 'rating obtained primarily by farming'. So they could've farmed in order to get to a higher rating bracket to join. (I could check their highest rated win, but still.)

**In games like csgo and valorant (do they have sub battles? Idk lol), I can know exactly this.** If someone is rated 1600 in csgo or valorant (I know they're more on ranks / rating groups than ratings, but you know Gasai what I mean), then I know they've already beaten (or drawn with) someone of that rating. Like they didn't reach 1600 from just beating 1300 players or something.

# Answer
> 1 votes
Well, for one thing, you wouldn't be able to start things out this way. Imagine you have a new website and you start people at 1200. Nobody would ever be able to go above 1200 because nobody is there in the first place.

Even if you have an established player base, sometimes two new players will play each other. Under your proposal the winner wouldn't be able to gain any rating points. Indeed, anyone only playing people at their rating would have a difficult time gaining any points.

And this manipulation of the ratings would have a detrimental effect on the accuracy of the ratings as a whole. If you can beat 12 players in a row who are rated 1000-1149, your rating is almost certainly *not* 1149 or below. Telling the rating system that your rating is actually only 1149 is just going to make you underrated, and that has negative effects on your opponents' ratings as well.

OK, much of this can be mitigated with your stipulation that it doesn't have to be quite so strict and being within 50 points is enough. But then you're postulating a person with a strength of around 1326-1345 who can beat someone rated 1000-1149 more or less every time, but can't get a single win or draw against someone rated 1530 so they can legitimize that 1580 rating. Ratings aren't so absolute that a strength difference of 200 points will ensure a win for the stronger side.

---
Tags: rating, online-chess
---


# Question
Title: Given the value of a given piece is there a way to find the value of a similar piece that can only move, without capturing, or only capture?
Let's say the value of a piece that moves and captures in the same way is known. Then a similar piece that can move in the same way as the piece of known value, but which cannot capture, and consequently cannot check or checkmate a king is probably less valuable than the piece it has similar moves to, although a piece that cannot capture could still be useful for blocking the movement of other pieces. Similarly if there was a type of piece that could capture like a chess piece with known value, but which could only move when capturing, then it probably wouldn't be as valuable as said piece as it would not be capable of moving to attack another piece without capturing something first. Of course something that moves like a queen but cannot capture would probably be more valuable than something that moves like a rook but cannot capture. Similarly something that captures like a rook but can only move to capture would probably be more valuable than something that captures like a knight but can only move when capturing.

So if the value of a given piece is known, whether it be a standard piece or fairy piece, is there an algorithm to find the value of a similar piece that can move but not capture, or piece that can only move when capturing?

# Answer
> 2 votes
Fairy-stockfish can help you with this. You can define pieces you described. To find the optimal piece values, depends on your starting position and board size. Create some start positions, do some engine vs engine matches to optimize piece values. You can do trial and error but can be automated.

I make a sample start position. Check the **startFen** below.

Per fairy-stockfish variants specs, the following is its definition that can be added in variants.ini file.

```
[crazy:chess]
pieceToCharTable = PNBRQ......T.C.D.E...Kpnbrq......t.c.d.e...k
customPiece1 = e:mN
customPiece2 = c:cN
customPiece3 = t:mB
customPiece4 = d:cB
startFen = rdeqkctr/ppnbbnpp/2pppp2/8/8/2PPPP2/PPNBBNPP/RDEQKCTR w KQkq - 0 1
pieceValueMg = e:200 c:250 t:200 d:250
pieceValueEg = e:80 c:200 t:80 d:200

```

Notice the customPiece definition.

```
e:mN
e is piece type, m=move without capture, N=knight
The mN is called the betza notation.

```

```
c:cN
c is piece type, c=capture, N=knight, cannot move to empty square

```

```
t:mB
B is the bishop that cannot capture.

```

```
d:cB
B is the bishop that can capture, but cannot move to empty sq.

```

You can define any startpos, board size, piece types and others.

Read the betza to define how the piece moves.

#### Sample game

```
[Event "Computer Chess Game"]
[Site "?"]
[Date "2022.12.05"]
[Round "2"]
[White "crazy2"]
[Black "crazy1"]
[Result "0-1"]
[TimeControl "120+1"]
[Variant "crazy"]
[VariantMen "P:fmWfceFifmnD;N:N;B:B;R:R;Q:Q;T:mB;C:cN;D:cB;E:mN;K:KO2"]
[FEN "rdeqkctr/ppnbbnpp/2pppp2/8/8/2PPPP2/PPNBBNPP/RDEQKCTR w KQkq - 0 1"]
[SetUp "1"]

{--------------
r d e q k c t r
p p n b b n p p
. . p p p p . .
. . . . . . . .
. . . . . . . .
. . P P P P . .
P P N B B N P P
R D E Q K C T R
white to play
--------------}
1. e4 d5 2. d4 e5 3. Ne3 a5 4. a4 Be6 5. Nf5 Bxf5 6. exf5 Na6 7. Qb3 Ra7 8.
h4 h5 9. Nd3 Nd6 10. Nf2 exd4 11. cxd4 Nb4 12. Th2 b6 13. Nd3 Na6 14. Nf2
Qc7 15. Nd1 Nb4 16. Qe3 c5 17. Nc3 Kd8 18. Ra3 c4 19. Kf2 Qc6 20. Kg1 Rd7
21. f4 Ne8 22. Tg3 Na6 23. Ra2 Bb4 24. Bf3 Nac7 25. Qe2 Ed6 26. Bxh5 Ee4
27. Bg4 Nd6 28. h5 Re7 29. Qd1 Kc8 30. Tf2 Qd7 31. b3 Kb7 32. Rh3 Ka7 33.
bxc4 Bxc3 34. Bxc3 Nxc4 35. Qb3 Ne8 36. Bf3 Dxf4 37. Dxe4 dxe4 38. Be2 Ncd6
39. d5 Qb7 40. Bb5 e3 41. Bc6 Qa6 42. Te1 Qc4 43. Qxc4 Nxc4 44. Ee2 Ned6
45. Rc2 Tf7 46. g4 Kb8 47. Kg2 Re4 48. Rc1 Rh6 49. Rd1 Ne5 50. Bxe5 fxe5
51. Rb1 Rb4 52. Rxb4 axb4 53. Kf3 b3 54. Ec3 e4+ 55. Ke2 Nc4 56. Cxe3 Ne5
57. Bb5 Kc7 58. Eb1 Kd6 59. Bc4 b2 60. Kd1 Kc5 61. Kc2 Kd4 62. Tb4 Nxc4 63.
Cxc4 Kxc4 64. Rc3+ Kxd5 65. Rc8 Rc6+ 66. Rxc6 Kxc6 67. Kxb2 Kc5 68. Te1 Kd4
69. Kb3 Kd3 70. Kb4 Td5 71. Kb5 e3 72. Kxb6 Ta8 73. a5 Ke2 74. Ea3 Kxe1 75.
a6 Kd2 76. Ec2 e2 77. Ee1 Kxe1 78. h6 gxh6 79. Ka7 Kd2 80. Kxa8 e1=Q 81.
Kb7 Qe4+ 82. Kb6 Qb4+ 83. Kc6 Kd3 84. g5 Kc4 85. f6 Qb5#
{Xboard adjudication: Checkmate} 0-1

```

# Answer
> 1 votes
This doesn't tell you that actual value of said pieces, but you can expect any such piece to be worth far less then a pawn. https://www.chessvariants.org/d.betza/chessvar/ghost.html Here is a chess variant called "The Black Ghost". It's a variant where, to balance out whites first move advantage, black is given a piece that can move ANYWHERE, but can't capture. And in that variant, the "ghost" is generall worth less then a pawn.

So your example pieces are going to be worth far less.

# Answer
> 0 votes
Assessing the relative values of kinds of piece is already tricky because, as a game progresses, more and more units get captured, so the power of the remaining ones changes. The size of the change depends on the nature of the piece's move: bishops gain much power from diagonals opening; knights, less so.

If a piece can only move if it captures, it gets weaker because opportunities to capture anything get fewer and further between. Compare such a piece to a hopper (e.g. a grasshopper, or the cannon in xiangqi), which may move with or without capturing on its arrival-square, but must leap over another unit in order to reach that square.

---
Tags: point-value, unorthodox-pieces
---


title: What is the point of shark points?

text:
# Question
Title: What is the point of shark points?
In this tweet Benjamin Portheault gives this alternate scoring for the current Wijk event:

Can anybody explain what is going on here beyond just *Sharkpoints = Waste + Points*? What are they supposed to be measuring? Where do these numbers come from? If they are supposed to give a fuller (probably just different) view because just "points" isn't enough then they fail because "Sharkpoints" also fail to account for "waste".

# Answer
Benjamin Portheault links this tweet as an answer to a similar question under his tweet. If I understand the metric correctly, then each game is evaluated and for the worst and best positions of that game a win probability is computed. The waste points are then taking the win probabilities of the best evaluations and compare them with the actually achieved points. Similarly, the save points are computed for the win probabilities of the worst positions and compared against the actually achieved points. The shark points is then the number of points a player could have achieved for never "wasting" together with their actual "saving".

For example, Vincent Keymer appears to have played many games in which the engine was giving him good evaluations at some point in the game. However, he did not manage to capitalize on that and scored only 3.5 points. According to the waste measure, he should have scored another 4.51 points to a total of 8.01. Magnus Carlsen, conversely, was often in positions that were disfavored by the engine. Yet, he scored a total of 6 points, which is 4.06 points more than predicted according to the save measure.

As the all these measures are computed as the sum over probabilities, they do not correspond to actual game outcomes (as can be seen by the decimal values) and it could be that two players would gain shark points for the same game. For example, if Keymer plays Carlsen and first Keymer reaches a position that is strongly evaluated in his favor, and later Carlsen has the better evaluation, but in the end they draw. In this case, both players would have "wasted" this game and would have corresponding waste and shark points. Yet, realistically, only one player could have turned their advantage into an actual score point.
> 4 votes

---
Tags: scoring
---


title: How to learn to play blind

text:
# Question
Title: How to learn to play blind
Is there a standard way to learn to play blind? How should one go about becoming better at blind chess? Should it come "natural" to a player at some point?

I am interested in knowing if it is a skill to learn or something that is simply a proof of a player's ability and so can't be learned before one reach like master level or something.

# Answer
As others have mentioned, the "normal" way to learn to play blindfold is to simply get better at chess. A strong amateur will be able to play a game blind without much specific training. This is due to chunking—being familiar with lots of patterns makes memorizing those patterns much easier.

That being said, there are specific exercises which can help a weaker player play blindfolded:

0. **Become extremely well versed in coordinates**. It is impossible to play Blind without this. See this trainer for instance.
1. **Tactics involving deep calculation**. Deep calculation while looking at a board is essentially the same muscle as holding a position in your head.
2. **Quiz yourself on the color of each square**. This will help you get a feel for the board.
3. **Mentally move single pieces around in your head**. Especially knights and bishops (long diagonals can be tricky). Write down 10 of these moves and check that they were legal afterwards. You should be able to do this reasonably quickly.
4. **Practice**. Lichess has a Blindfold setting where the pieces vanish. Not quite as good as proper blindfold (you can still see the board...) but it's a good stepping stone.
> 4 votes

# Answer
Here is a website that helps you learning blind chess: https://chessninja.org

Several similar sites exsist. They offer exercises to practise board visualization.
> -4 votes

---
Tags: learning, blindfold-chess
---


# Question
Title: Why is there a minimum rating gain when you win?
Fide has a rule saying that if one player is rated more than 400 points higher than his opponent, their difference should be set to 400 when calculating rating gain/loss. That means no matter how weak the opposition is, a GM (or anyone) will receive minimum 0.8 rating points for winning. What is the reason behind this?

To me it just seems like a giant weakness in the rating system, making any strong GM able to get as high rating as he wants just by playing weak opponents. Wouldn't it be better if the gain approached 0 when the difference increased (like the basic formula for calculating rating actually does)?

EDIT: As most of the answers don't really seem to get the point, I will add an example which points out the problem:

One of the top 10 players in the world (say Magnus Carlsen), wants to increase his rating to 3000. He has a good friend who has 1200 in rating, and who is willing to play a match of 200 games (2 each day for 100 days) against him. His friend will of course play his best, so this is by no means considered cheating.

According to https://wismuth.com/elo/calculator.html, Magnus will have way more than 99 % chance of winning a single game, but for simplicity, let's say he has 99 % chance of winning a game (which is an understatement). If we then forget about draws (for simplicity), Magnus would be expected a score of 198/200. That means a rating gain of 0.8\*198 - 9.2\*2 = 140 rating points. That is if he scores as expected. And he used less than 1/3 of a year, and is extremely close to 3000 already. What if he does it again? (And again?) Even if he plays really poorly and loses 5 and draws another 5 out of the 200 games, he will gain 85 rating points. That is by scoring FAR below expected.

If there was no rating difference cap, playing an expected result (say 198/200), would by definition give a rating gain/loss of 0. So who came up with the idea of making a loop-hole for any top GM to become extremely high rated?

Of course it would be looked at as bad sportmanship to do something like this, and I doubt any of the top players of the world would consider doing so, but that doesn't justify the possibility being there. In a serious sport with a serious rating system there shouldn't be these kind of loop-holes.

Can anyone find any arguments justifying this rule?

# Answer
> 21 votes
> Fide has a rule saying that if one player is rated more than 400 points higher than his opponent, their difference should be set to 400 when calculating rating gain/loss. That means no matter how weak the opposition is, a GM (or anyone) will receive minimum 0.8 rating points for winning. What is the reason behind this?

This is an historical anomaly. Currently, apart from your first ever rating, every game is rated individually. This means that you can never lose rating points by winning a game (LRPBWAG). It wasn't always so.

I don't remember exactly when the change happened, 2008 I think, but before this ratings were calculated per tournament. What happened was that your rating was calculated using your score for the tournament, the average of your opponents' ratings and your expected score against them. This opened up the possibility of winning the tournament but losing rating points because some low rated players in the tournament, who you crushed, lowered the average rating for the tournament so much that even though you scored well against similarly rated players as yourself your rating went down.

The original solution to this was to limit the difference to 350 points. Later this was changed to 400. Now that games are rated individually it could be scrapped.

There was an article on Chessbase 6 years ago discussing this point between Jeff Sonas, Ken Thompson and John Nunn.

Part of John Nunn's contribution is worth quoting -

> The original rating rules had no 350-point rule. It must be remembered that in 1970 the rating list was very small and it was never envisaged that it would be extended substantially. Only top tournaments were rated (and these were invariably all-play-all events) and all calculations were done by hand. The 'Losing Rating Points For Winning A Game' problem didn't really arise. The top players always skipped the first round or two of an Olympiad, and in any case any weak opponents would be unrated, so the games simply didn't count.
>
> But times changed, the rating list expanded and started including more and more weaker players. Open tournaments appeared, and the LRPFWAG problem started to become significant. I don't remember exactly when the 350-point rule was introduced to deal with this, but I believe it was around 1980. Later, in 1988 or 1989, Karpov was unhappy about losing points when he had won a tournament, arguing that the aim of taking part in a tournament was to win it, and if you have achieved that then you shouldn't lose points through not having won by a large margin. For a time the 'Karpov rule' was in effect, that you couldn't lose points for winning an event. This was later scrapped.
>
> Rating games individually is a fairly recent innovation, and for the vast bulk of the lifetime of the Elo system it was done on a tournament basis (because it made the calculations easier, especially for all-play-all events). The current rule is in a way a hangover from the earlier times, but I think there is some logic in it, although one can argue over the exact details. Rapidly improving young players, for example, can be massively underrated.

# Answer
> 13 votes
The rule makes total sense to me as statistics for rating is not so accurate when the difference in playing strength is too much. Capping to 400 minimises the statistical damage.

No GM would risk a hefty rating penalty by playing only weak tournaments. Too much risk for very little gains. A single tactical oversight (GM is human too!!) could be deadly.

# Answer
> 8 votes
For starters, eight-tenths of a point really isn't that much of a ratings gain, especially for someone rated 2600 or more. At that rate, it would take 100 wins (without an upset loss) against these lower rated players just to gain 80 points. Given that a GM would mostly have to limit him/herself to the 3 to 6 round weekend tournaments that most of us lower rated players primarily participate in, it would take a while to gain those 80 points. Also, some tournaments might not allow a GM into the lower rated sections. Additionally, the prize money would be almost insignificant for a player at that level. As noted in Jossie Calderon's answer, such a point grab would invite challenges from other GM's looking for a big point gain. All in all, it just doesn't seem like a smart way to gain points.

As I see it, this isn't about guaranteeing a minimal increase for a GM. It's more about capping the gain for a lower rated player and minimizing the loss for the higher rated player if somehow some patzer manages to upset a GM, or a seriously underrated player beats the GM.

# Answer
> 8 votes
The higher rated player should get something for winning a game, and 0.8 seems to be the least to award the winner and still get recognition.

https://en.wikipedia.org/wiki/Claude\_Bloodgood exploited the this system to achieve a rating of 2759.

# Answer
> 7 votes
It all evens out when an underrated opponent defeats the GM.

Assume the GM only plays weak opponents, so he gets a considerably large rating.

Then when he gets inevitably famous (he's a GM) people are going to look up his playing history and notice a discrepancy. This guy is only good because he plays patzers!

So when an underdog defeats him (this underdog being several hundred points stronger than he is on paper) the GM's rating will shift towards a truer description.

**EDIT** As a response to your edit, you do realize everyone around the world can see Carlsen's playing history, right?

Don't you think this would affect his image somewhat...I don't know...NEGATIVELY?

You're just asking a theoretical question that doesn't have a basis in real life. That's why you're not getting the answer you want: **there is no solution.**

# Answer
> 1 votes
Previous answers to this question were correct but are now outdated. As of 2023, the 400-point-gap rule is only applying to one game per month per player rather than to every single game.

---
Tags: rating, fide
---


title: Trading bishops

text:
# Question
Title: Trading bishops
In many cases a bishop pair is stronger than a bishop and a knight or two knights.

The question is, if both sides have already traded one of their bishops, losing the bishop pairs, should the other ones be traded as well?

# Answer
> 3 votes
First, note that

> It is well-known that a bishop pair is stronger than a bishop and a knight or two knights.

is wrong, strictly speaking. Wheter either of these combinations is strongest depends on features of the position at hand, mainly the pawn structure, with pawn islands and outpost squares as its main aspects.

Second, note that trading without a gain, a clear reason why, is usually bad. Trade if there is a concrete reason, otherwise don't. Concrete reason includes longterm assets such as weak colour complexes.

In *open or semi-open* positions a bishop pair is often murder, and a lone bishop is usually superior to a lone knight. The knight is superior to the bishop in *blocked* positions or when the bishop is hemmed in by pawns on the same colour squares as the bishop.

In general, you should trade either of your pieces against your opponents remaining bishop if they have a weak color-complex thats currently defended by their bishop, even at the cost of trading your bishop, no matter what case, and you should not allow your opponent to trade either of their pieces for your remaining bishop if you have a weak color-complex yourself.

A special treatment is deserved when both sides have opposite coloured bishops; here, the initiative is played a piece up. Thus, when you're defending, trade for their bishop if possible, and refrain from trading if you have the iniative.

In short: Don't trade unless there is a shortterm gain or a longterm asset to play against, and let the pawn structure be the deciding factor.

---
Tags: knights, bishops, trading, bishop-pair
---


# Question
Title: In the 2019 WFRCC, did anyone catch up in a match after losing in the 'slow rapid' (classical?) portion?
From Wikipedia

> Each match of the quarterfinals consisted of two “slow” rapid games (45 minutes for 40 moves plus 15 minutes for the rest, without increment), two “fast” rapid games (15 minutes plus 2 seconds increment) and 2 blitz games (3 minutes plus 2 seconds increment). The games were weighted differently: 3 points for each slow rapid game, 2 points for each fast rapid game and 1 point for each blitz game.

I believe this applies to the semi-finals and finals too. For the 9 matches of the quarter-finals and the 4 matches of the semi-finals and finals (4 includes the 3rd place match), for anyone that lost the 45min (slow rapid? Classical?) portion of their match, did they catch up and win the overall match?

# Answer
No, but 5 out of 13 slow rapid portions were drawn. (However, none of the semi-finals or finals slow rapid portions were drawn.)

Semi-finals:

* Magnus vs Fabi - Magnus won the slow rapid 7.5-4.5 & then overall 12.5-7.5.
* Nepo vs Wesley So - Wesley So won the slow rapid 9-3 & then overall 13-5.

Finals & 3rd place:

* Nepo vs Fabi - Nepo won the slow rapid 7.5-4.5 & then overall 12.5-5.5.
* Magnus vs Wesley So - Wesley So won the slow rapid 10.5-1.5 & then overall 13.5-2.5.

Quarter-finals Day 1:

Quarter-finals Day 2:

Quarter-finals Day 3:
> 2 votes

---
Tags: fide, chess-variants, world-championship, chess960
---


title: c5-c4 pawn sacrifice in Benoni line

text:
# Question
Title: c5-c4 pawn sacrifice in Benoni line
Consider the following line

```
[FEN ""]
[StartPly "23"]
[StartFlipped "1"]

1. d4 Nf6 2. c4 c5 3. d5 e6 4. Nc3 exd5 5. cxd5 d6 6. e4 g6 7. Bd3 Bg7 8. Nge2 O-O 9. O-O Nbd7 10. f4 a6 11. a4

```

Stockfish says that **c4** is the best move here. The line then proceeds normally, as if nothing happened, with **12. Re8**

I know that the general game plan is to expand on the queen side, but I don't see why this pawn sacrifice is so necessary.

What is the idea behind this sacrifice then?

# Answer
> 2 votes
The pawn is only temporarily sacrificed. Black can regain it tactically after a few moves, although it's not readily obvious how that happens. It should be mentioned that instead of 11...c4, 11...Qa5 which prepares c4, is a completely fine move. Here I provide a few sample variations that show what happens if White desperately tries to hold on to the extra pawn.

```
[FEN ""]
[StartFlipped "1"]

1. d4 Nf6 2. c4 c5 3. d5 e6 4. Nc3 exd5 5. cxd5 d6 6. e4 g6 7. Bd3 Bg7 8. Nge2 O-O 9. O-O Nbd7 10. f4 a6
11. a4 c4 (11... Qa5 {is a fine move, preparing c4. For example} 12. Ra3 c4 {and now the pawn cannot be taken without seriously compromising White's position}
13. Bxc4 $2 Qc5+ 14. Qd4 Nxe4 $1 $15) 12. Bxc4 Re8 {and it is difficult for White to hold on to the extra pawn. For example}
13. Ng3 Nc5 14. Bd3 $6 (14. Re1 $6 h5 15. e5 dxe5 16. fxe5 $2
(16. f5 {is better}) 16... Ng4 17. e6 Bxe6 18. dxe6 Bd4+ $19)
(14. e5 $1 dxe5 15. f5 $1 $14 {is good.})
14... h5 {threatening h4, which undermines the g3 knight that
defends e4. There's not much that White can do about it.}
15. h4 $4 ({Admitting the mistake with} 15. f5 {is better} h4
16. Nh1 Ncxe4 17. fxg6 Qb6+ 18. Nf2 fxg6 $15)
15... Ng4 $19 {and now h4 falls and with it the game as well.} *

```

The idea behind the sacrifice is to simply mobilize Black's pieces. The Black knight wants to come to c5 and pressure e4. Then the rook can join in from e8 to attack e4 as well. That also makes the knight on f6 more effective, and so on...

---
Tags: sacrifice, modern-benoni, benoni
---


# Question
Title: How does FIDE define slow rapid & fast rapid?
**Note: This has practical implications** if that's what you were wondering about. How can Hikaru in 2022 WFRCC be a successor of Wesley in 2019 WFRCC if 32.5min & 60min aren't in the same time control range?

---

I don't think I've ever heard these terms 'slow rapid' and 'fast rapid' outside chess960. Just now I tried looking up "slow rapid" "chess" "fast rapid" and "slow rapid" "fast rapid" and then almost everything there is chess960.

# Link 1

In the 2019 WFRCC, the following I believe applies for the semi-finals and finals besides just the quarter-finals:

> Each match of the quarterfinals consisted of two “slow” rapid games (45 minutes for 40 moves plus 15 minutes for the rest, without increment), two “fast” rapid games (15 minutes plus 2 seconds increment) and 2 blitz games (3 minutes plus 2 seconds increment). The games were weighted differently: 3 points for each slow rapid game, 2 points for each fast rapid game and 1 point for each blitz game.

# Link 2

In the 2022 WFRCC, whatever 'slow rapid' means, FIDE categorises their 25min games as slow rapid, same as their 45min games but unlike their 15min games which are 'fast rapid'.

> The time control is so-called 'slow rapid': Each game is 30 moves in 25 minutes, plus 5 minutes for the rest of the game after move 30, plus 5 seconds increment per move starting from move 31.

**Question**: How does FIDE define 'slow rapid' and 'fast rapid' ?

**Note 1**: Actually about the rapid WCC, I read just now:

> In order to promote viewership, time controls were set at 15 minutes per player, rather than the pre-2012 standard of 25 minutes.

* In chess, 25 is in the same category as 15
* But in 960, 25 is in the same category as 45.

**Note 2**: If rapid is just 10-59 minutes, then I don't think slow rapid just means above the midpoint of 35 minutes since '25 minutes per player for the first 30 moves, after which each player will receive additional 5 minutes on the clock and an increment of 5 seconds per move starting from move 31' converts to 32.5 minutes and is considered slow rapid.

# Link 3

Update: Chess stackexchange re 2024 Grenke Chess Classic. - oh there's a new thing 'fast classical'. I think synonymous.

How does FIDE define fast classical?

# Link 4

Chess.com calendar archive

https://www.chess.com/article/view/chess-tournaments-calendar-archive

This actually says

> FIDE World Fischer Random Chess Championship Wesley So won the first FIDE sanctioned Fischer Random World Championship. News report. (Slow rapid & rapid)

Meaning 'slow rapid' in 2019 WFRCC could be different from 'slow rapid' in the others.

# Link 5

Chess24 Calendar 2023 (archive since RIP chess24) - The FIDE Women's World Team Championship in Poland for 2023Sep was 'slow rapid'.

https://web.archive.org/web/20231126214851/https://chess24.com/en/read/news/chess-calendar-2023

> This 12-team event combines round-robin and knockout elements with the teams of four players competing in a "slow rapid" format with just under an hour per player in each game.

Then the website says https://worldwomenteams.fide.com/

> The time control is 45 minutes for the whole game with an increment of 10 seconds per move starting from move 1.

# Answer
> 3 votes
Quoting from the FIDE Handbook

Appendix A defines "Rapid Chess":

> A.1 A ‘Rapid chess’ game is one where either all the moves must be completed in a fixed time of more than 10 minutes but less than 60 minutes for each player; or the time allotted plus 60 times any increment is of more than 10 minutes but less than 60 minutes for each player.

Appendix B defines "Blitz:":

> B.1
>
> A ‘blitz’ game is one where all the moves must be completed in a fixed time of 10 minutes or less for each player; or the allotted time plus 60 times any increment is 10 minutes or less.

No other form of game is referred to - so all other time controls fall under the same heading. I think most people would call this "Classical" but note FIDE uses no such term. It also does not talk about "Slow rapid" or "Fast rapid". So the short answer to the question on the title is it doesn't. IMO the use of slow and fast in the quoted text are merely qualifiers to the term rapid, indicating at which end of the spectrum the time controls fall, rather than an official designation.

# Answer
> 2 votes
For regular chess, there's no official definition other than "Blitz", "Rapid" and "Classical". Distinctions inside each of these three categories would be a matter of opinion.

---
Tags: fide, chess-variants, world-championship, time-control, chess960
---


# Question
Title: Why didn't Wesley So get full championship privilege in the 2022 WFRCC unlike Magnus and Vishy did since 2008?
Wesley So didn't get full championship privilege in the 2022 WFRCC unlike Magnus and Vishy did from 2008 to 2021. **They got only 1 opponent** to defend against, namely the unique winner of a candidates tournament. Had this been the case for the 2022 WFRCC, Wesley So's I guess guaranteed at least the 2nd place prize of US$85,000. Instead, **Wesley So had to defend against 7 other players.** It's partial privilege at least. Better than no privilege at all like in blitz & rapid WCC's where the champion really starts from scratch. But still...

**Question**: Why didn't Wesley So get full championship privilege? In the absence of official explanation from FIDE, is there historical precedent for something like this?

**Guesses**:

1. FIDE was afraid of another complete obliteration like in the 2019 WFRCC where Wesley So beat Magnus 13.5-2.5.
2. Vishy and Magnus were so dominant (in chess) in their respective times (except when Magnus was starting to catch up to Vishy) and that FIDE was convinced they could be seeded into the finals. Meanwhile Wesley So didn't do so well (palindrome acronym WSDDSW) in fast rapid (20min games) in St Louis Chess 9LX 2020 and 2021. (And well yeah this was repeated in the 2022 Chess 9LX and 2022 WFRCC, both fast rapid.) --\> If this is your answer, then I'd like to please see some **historical precedence like: Did FIDE change championship privilege depending how convinced they were by the champion's ability to defend the title?**
3. Maybe for some reason the low time controls implies less reason for championship privilege like with the rapid & blitz WCCs. Maybe rapid & blitz WCC have the same fear from FIDE regardless of your rating simply because of the time control: We're not convinced you can defend even if you're Magnus, so we won't give you full / any privilege.

# Answer
> 1 votes
The simple answer is "tradition". Even before FIDE the regular chess world championship was organised on a champion vs challenger basis. The exceptions to this were in 1948 when Alekhine's death left the title vacant and a quintuple round-robin tournament between Botvinnik, Euwe, Smyslov, Keres and Reshevsky was held to decide the new champion and the PCA interregnum years when FIDE experimented with knock-out formats.

Interestingly the 1948 multiple round robin format is far and away the fairest / best system that has ever been used and the knock-out system the worst.

FIDE have only organised a chess960 world championships since 2019 and, thankfully, they are using the much fairer round robin format. This gives no player an advantage over the others and reduces the element of luck to the lowest possible level.

---
Tags: fide, chess-variants, tournament, world-championship, chess960
---


# Question
Title: If classical is 120 minutes+ and rapid is 10-59 minutes, then what's 60-119 minutes? 'Slow rapid'?
Wikipedia says that FIDE says for tournaments with 2200+ rated players,

>

1. Classical is 120 minutes+
2. Rapid is 10-59 minutes

So what's 60-119 minutes for tournaments with 2200+ rated players? 'Slow rapid' ?

# Answer
> 4 votes
> Wikipedia says that FIDE says for tournaments with 2200+ rated players

Wikipedia, not for the first time, is wrong. According to the latest FIDE rating regulations:

> **1. Rate of Play**
>
> 1.1 For a game to be rated each player must at the start of the tournament have the following minimum periods in which to complete all the moves, assuming the game lasts 60 moves.
>
> Where at least one of the players in the game has a rating of 2400 or higher, each player must have a minimum of 120 minutes.
>
> Where at least one of the players in the game has a rating 1800 or higher, each player must have a minimum of 90 minutes.
>
> Where both of the players in the game are rated below 1800, each player must have a minimum of 60 minutes.

Blitz is for games where the game time is 10 minutes or less according to Appendix B of the FIDE Laws of Chess:

> **Appendix B. Blitz**
>
> B.1 A ‘blitz’ game is one where all the moves must be completed in a fixed time of 10 minutes or less for each player; or the allotted time plus 60 times any increment is 10 minutes or less for each player.

And according to Appendix A:

> **Appendix A. Rapid Chess**
>
> A.1 A ‘Rapid chess’ game is one where either all the moves must be completed in a fixed time of more than 10 minutes but less than 60 minutes for each player; or the time allotted plus 60 times any increment is of more than 10 minutes but less than 60 minutes for each player.

So, the classification is:

Blitz \<= 10 minutes
10 minutes \< Rapid \< 60 minutes
Standard \>=60 minutes

Blitz and rapid can be rated for all standards of players but standard time control chess cannot be FIDE rated for \< 90 minutes if either player is rated \>= 1800 and cannot be FIDE rated for \< 120 minutes if either player is rated \>= 2400.

There is officially no such thing as "slow rapid". There is just chess which can be rated and chess which can't. Time controls are just a small part of that as the rating regulations make clear.

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


# Question
Title: Time control conversion when it comes to bonus time after eg 40 moves
I read that for increment games the way to convert them to non-increment games for the purpose of classification by time control goes as follows:

* Original time + Increment x 40 = Time used to classify

Eg 10min + 3sec increment is

* 10min + 3sec x 40 = 10min + 2min = 12min

So, if according to some federation or website, 11min is the cut-off between rapid & blitz, then 10min+0sec increment would be blitz while 10min+3sec increment would be rapid. But besides classification, every increment game can then be converted into a non-increment game as such.

**Question**: What's the conversion for time controls that give time bonuses after reaching a certain move into time controls are just X min + 0 increment (for the whole game) ?

Examples:

1 - 2022 Candidates:

> 120 minutes for the first 40 moves, 60 minutes for the next 20 moves, and then 15 minutes for the rest of the game, plus a 30-second increment per move starting from move 61.

2 - 2023 Tata Steel:

> The time control is 100 minutes for 40 moves followed by 50 minutes for 20 moves, then 15 minutes for the rest of the game, with a 30-second increment per move from move one

3 - 2019 WFRCC:

> 45 minutes for 40 moves plus 15 minutes for the rest, without increment

4 - 2022 WFRCC:

> The time control (for both the group stages and the knockouts) will be 25 minutes per player for the first 30 moves, after which each player will receive additional 5 minutes on the clock and an increment of 5 seconds per move starting from move 31.

# Answer
> I read that for increment games the way to convert them to non-increment games for the purpose of classification by time control goes as follows:
>
> Original time + Increment x 40 = Time used to classify

If you did read that (no reference given) then you read wrong. "Game time" is based on a game lasting 60 moves according to the latest FIDE rating regulations:

> 1. Rate of Play
>
> 1.1 For a game to be rated each player must at the start of the tournament have the following minimum periods in which to complete all the moves, **assuming the game lasts 60 moves**

1 - So, for

> 120 minutes for the first 40 moves, 60 minutes for the next 20 moves, and then 15 minutes for the rest of the game, plus a 30-second increment per move starting from move 61.

the game time (time for first 60 moves) is 180 minutes (120+60+0) i.e. players have 180 minutes to play 60 moves

2 - For

> The time control is 100 minutes for 40 moves followed by 50 minutes for 20 moves, then 15 minutes for the rest of the game, with a 30-second increment per move from move one

the game time (time for first 60 moves) is 180 minutes (100+50+30) i.e. players have 180 minutes to play 60 moves

3 - For

> 45 minutes for 40 moves plus 15 minutes for the rest, without increment

the game time (time for first 60 moves) is 60 minutes (45+15) i.e. players have 60 minutes to play 60 moves

4 - For

> The time control (for both the group stages and the knockouts) will be 25 minutes per player for the first 30 moves, after which each player will receive additional 5 minutes on the clock and an increment of 5 seconds per move starting from move 31.

the game time (time for first 60 moves) is 32.5 minutes (25+5+2.5) i.e. players have 32.5 minutes to play 60 moves. That is 30 minutes for the first 30 moves then 5 minutes plus 2.5 minutes of increment for the next 30 moves.
> 3 votes

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Tags: fide, tournament, time-control
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# Question
Title: Chesscom's new policy allows users to choose starting rating - Is this actually harmful to the rating system?
For simplicity, let's focus on just 1 time control.

In chess.com: I've previously reached a peak rating of 1360 under a starting rating of 1200. Then I stopped playing chess on chess.com for awhile (e.g., I went to lichess or chesscube or chess24 only). During this time, chess.com changed their rating policy to allow people to choose their starting rating between I think 400, 800, 1000, 1200, and 1500.

**Question: Despite the supposed benefits, is it actually overall harmful to the rating system or confusing for players who started in the old policy?**

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Here's why I think this is harmful to the rating system:

## For players who started in the old policy:

If most people choose, say, 1000, then...

Let's say I was around 1240-1290. Then when I get back, I would've been, under the old policy, 1370 - 1420 and so I would've gotten a peak rating of maybe 1490.

1. But now if everyone is choosing 1000, then it seems my rating is going to be like 1170 - 1220 with a peak of 1290.
2. This 1290 is not going to be in my statistics. It will still say my peak is 1360. Now, 1360 is a lot higher than the 1360 before. 1360 now is like 1560 before.
3. This 1360 gives people, including myself, the wrong impression, but this can be avoided if I just make a new account under the new starting rating policy.

## For all players:

4. If an overwhelming majority of people choose 1000, then it's the same thing as changing the starting rating to 1000.

## Actually even for players who start in the new policy:

5. If 2 people are about the same strength but then select different starting ratings... like let's say 10,000 players about 1300 on lichess join chess.com. But 5,000 pick 800 and another 5,000 pick 1000. If they play against people only of their own chess.com strength say (-25,25), in particular if these 10,000 actually make up majority of the entire chess.com pool (or you can imagine maybe there's a new chess website and then 10,000 lichess players join) then it seems we may have situations where there are people of ratings 200 points apart like 800 and 1000 but their actual strength is the same.

* 5.1. And then there's possibly no correction for it because these 1000-rated players never really play against these 800-rated players because they always pick (-25,25) opponents.
* 5.2. If I were such a 1000 and were to play against such an 800 rated player say in a private challenge then they are underrated and there is a huge asymmetry. Even if this is fixed in the long run, this is a huge hit for me in the short run.

6. I think it's harder to convert chesscom to lichess ratings now this way. Ignoring the glicko 1 vs glicko 2 thing, just pretend it's the same pool and it's 1200 vs 1500. Then I think it's simply a matter of doing +/- 300.
7. I think guess the rating eg eloguessr or Levy's guess the elo series will be much more difficult esp if players don't have a variety of opponents.

* 7.1. If they had played under the old policy then their peak rating might be nonsensical.

# Answer
It really depends on whether people can accurately approximate their own strength when making an account. I don't have any information on whether people can do so or not.

But keep in mind that RD makes this not matter as much as you'd think.

> in particular if these 10,000 actually make up majority of the entire chess.com pool

If you have 10,000 new players who are all the same strength and make up the majority of the pool I think you can expect weird things to happen to your existing players no matter what you do. It's not a reasonable assumption.

> And then there's possibly no correction for it because these 1000-rated players never really play against these 800-rated players because they always pick (-25,25) opponents.

But you're not staying at your selected rating unless you somehow get all draws. If you select an initial 800 rating and you win your first game against someone rated 800 whose RD is 76, your new rating will be 975 and you'll be playing against those 1000 players in your next game anyway. Conversely, someone who selected a 1000 rating who loses their first game against an established 1000-rated player will drop to 825 and be playing the 800 players.

> If I were such a 1000 and were to play against such an 800 rated player say in a private challenge then they are underrated and there is a huge asymmetry. Even if this is fixed in the long run, this is a huge hit for me in the short run.

If you have a rating of 1000 and an RD of 76, you'd lose about 11 points for losing to a brand new player with a rating of 1000. Losing to a brand new player with a rating of 800, you'd lose 15 points instead. The hit in the short run wouldn't be that huge.
> 2 votes

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Tags: rating, chess.com
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