# Question
Title: Is there a mathematical theorem that you can use to win a chess endgame?
Have mathematicians created any theorem that determines the outcome of a endgame? If so, how could it be used to win a specific endgame?

# Answer
> 39 votes
Unfortunately the (original) question was a bit ambiguous and arguably still is. I try to sort the different interpretations out:

* Chess fulfils all requirements of "standard" game theory (zero-sum, two players, full information, no chance). This is your main theorem. Thus Chess *could* be solved principially - "just" create a 32 piece tablebase :-) In praxis, this of course is hopeless, cf. Allure's points. At the moment (2021), Chess is completely solved for 7 piece endgames, 8 is the next goal and in the works.
* OK, assume you meant "solve some *specific* given position" instead. In this case, an unconditional "yes". For only one example, look up Noam Elkies' work on simple pawn endings (although identical results can be obtained with classical chess analysis - arguably it looks more elegant in Conway notation instead - at least to a mathematician).

# Answer
> 20 votes
Such a theorem doesn't exist.

The closest is the strategy-stealing argument that can be used to show that for many games, the second player does not have a winning strategy. The gist of the argument is that if the second player did have a winning strategy, then the first player can play a random move and then adopt that strategy. If the random move is never a disadvantage (e.g. in Hex) then the first player would have a winning strategy, thereby proving by contradiction that the second player cannot have a winning strategy and the first player always wins (or the game ends in a draw).

This argument does not work for chess because there are positions where you don't want to make a move since any move is fatally weakening (zugzwang).

# Answer
> -4 votes
Your question is a bit ambiguous, so I will attempt to answer it in the manner I think you will find most useful.

---

1. Well the whole of chess / 9LX isn't solved, but there are endgame sort of 'theorems' in the sense that there are positions that are **provably** wins/draws and so if you know the theorems and their proofs, then theoretically you know how to win/draw those positions.

See the 1st 40 seconds of this video:

https://www.youtube.com/watch?v=mCsc24k-Q8M

2. **Loophole**: these are mathematical theorems in the sense that chess / 9LX is a mathematical game
3. Karsten Müller talks about something like this at timestamp 5:20 in an interview with chessbase india: Endgames are like pure maths in the sense that they are something to prove. In contrast, openings are like applied maths or statistics like 'which opening has a high/er draw rate?' or 'which opening leads to early queen trades (or reaches endgame early)?'

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Tags: endgame, theory, mathematics, solving
---


# Question
Title: Why don't these statistics disprove white's supposed larger (practical?) advantage in chess960?
I've read that, at least theoretically, white has a larger advantage in 9LX as compared to chess. (See **appendix**.) This seems to be assumed in practice to the point that in some 9LX tournaments, such as the inaugural FIDE 960 world championship, they have players play both colours for any given starting position.

To even begin to talk about that white has more of a practical advantage, I think we should have some statistics that show there is a higher winning percentage change between white win and black win in 9LX as compared to standard. (Then afterwards we see if this increase is statistically significant or not.) But actually 'it's the reverse'! The winning percentage change is lower! See here (and hopefully here later on):

* in standard, white has 23% advantage against black: (39.2-32)/32=0.225, but
* in 960, white has only 14% advantage against black: (41.6-36.5)/36.5=0.13972602739
* (By advantage i mean percentage change between white win rate and black win rate)

In particular those are statistics based on engine games. My thought is that these statistics show how far theory and practice are here given that even engines, under time pressure, do not make the most of the white's 1st move theoretical advantage.

**Question**: What's going on? What's the basis for all this practical/theoretical advantage in 960 or at least for the both colours thing in 960 tournaments (perhaps it's not about white's advantage or perhaps they're just going on the theoretical advantage given lacking data on practical advantage or something) ?

**Guess**: Wait I think I just figured it out. Even if in 9LX white has a **lower advantage** (again, percentage change between white win rate and black win rate), say, in the above case of 14% vs 23%, white still has a **higher win rate** like 41.6% vs 39.2%. So, like, white's *comparative advantage* (lower percentage change) to black is decreased, but white's *absolute advantage* (of higher win rate) is increased...?

In this case I'd like to submit for consideration that comparative advantage be used as a counter-argument to absolute advantage in saying they must play both colours in 960 tournament or something, but I guess I'd save this part for another post and perhaps not on stackexchange.

---

**Appendix on white's theoretical advantage** (I actually didn't think I needed to cite because I thought this is why they do the both colours thing)

1. Starting positions in Chess960 where black is definitely worse
2. https://www.chess.com/article/view/whats-the-most-unbalanced-chess960-position
3. What are the best scoring openings in Chess960?
4. From here (Why isn't Chess960 the standard?):

> Another problem with Chess960 is that some positions are more unbalanced than the traditional starting position. While some positions are also more equal, there are a few positions which start with more than twice the "normal" White advantage.

5. From When are we getting a World Chess960 Championship with classical time controls?

> There are some positions where White has a statistical chance to win of more than 60%. That's 6-7% more than standard chess.

# Answer
> 4 votes
For the time being, without being certain one way or the other, I simply challenge the hypothesis:

You could look at eval tables and computer games (or human games, if a sufficient number are available separated by SP) to determine whether the White advantage is greater in Chess960, whether on average (mean, median) or how imbalanced SPs can get. Some limited evidence that the White advantage could be **smaller** in Chess960: http://www.computerchess.org.uk/ccrl/404FRC/opening\_report\_by\_white\_score.html (note the very high position of SP 518 in the ordered list).

* \[**EDIT**: The Sesse evals for the 960 SPs vary from 0.00 to 0.57 and seem to confirm this, as SP 518 is evaluated at +0.22, ranked around 310/960 positions in terms of imbalance.\]

As for why "they do the both colors thing" - well, as far as I know, they don't necessarily. There are plenty of Chess960 tournaments (including the actual Chess9LX tournament for example) where they don't swap colors on a given SP against the same opponent.

Finally, I don't believe that, when used, this rule is implemented primarily because of imbalanced starting positions. I believe in general the motivation is something like 'players A and B have just played from SP z, and we don't really understand SP z well enough to know how much of an advantage this really conferred the White player, therefore let them play again with colors reversed'. For example, even if - and it is a big if - we have engines whose evaluation we can trust as much as we do our opening knowledge of SP 518 (the standard chess opening position), it is still possible that humans would find it much easier to play from White than Black, whereas we know very precisely the extent of this inequity in SP 518 thanks to enormous experience of human play from SP 518.

Note also that the rule is more or less automatically implemented in match play in standard chess (the exception being Armageddon).

# Answer
> 1 votes
I suspect that we can't really use human (or computer) performance as a barometer of advantage in 9LX games. Standard chess has been studied for hundreds of years, has boatloads of theory, has plenty of heuristics like developing knights before rooks, etc. A lot of this doesn't apply in 9LX. So humans (and maybe engines less so) will consistently play less optimal moves. Imagine you and I race a Ferrari against a Porsche and the Porsche wins. Does that mean Porsche is better? We can't really say since you and I are not professional racers and really didn't achieve peak performance.

I'd guess this applies to neural nets to a lesser degree and to traditional engines even less so.

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Tags: tournament, chess-variants, statistics, chess960
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# Question
Title: What did FIDE do/say in response to Magnus Carlsen's non-participation in the candidates match for the 2011 world championship?
In Why did Magnus Carlsen drop out of World Championship in 2011?

we see magnus said

> After careful consideration I’ve reached the conclusion that the ongoing 2008–2012 cycle does not represent a system, sufficiently modern and fair, to provide the motivation I need to go through a lengthy process of preparations and matches and to perform at my best.

What did FIDE do/say in response to this? Or at least what changes did FIDE make after this (whether or not it was necessarily in response to this) ?

# Answer
**FIDE response**:

> FIDE respects that every player makes his own decisions and regrets that GM Magnus Carlsen has expressed his desire to withdraw from the upcoming Candidates Matches. It is always a big loss for any event when a player of Magnus Carlsen’s strength is not participating. FIDE’s policy is to review regularly the World Championship cycle after consultation with the top world players. At this point in time, the current cycle is in its final stages and it is not possible for FIDE to change its regulations. In the case of GM Magnus Carlsen not participating, according to regulations GM Alexander Grischuk from Russia will be his replacement.

Have to love the irony in the "too late to make changes" claim, as one of the reasons Carlsen gave for not playing was the fact FIDE kept making changes all the way through the cycle. (Basically, the 2011 cycle was a hot mess. At the time of his withdrawal, no player, Carlsen included, had even seen a contract for the event or reliably knew what the terms would be.)

https://www.365chess.com/news/grischuk-will-replace-carlsen-in-the-candidates-matches-2011/

**Changes**:

The championship cycle is shorter, FIDE didn't change the rules in the middle of the cycle. No matches, just a super-tournament to select the challenger. From outward appearances, none of these changes was made in response to Carlsen. (In fact, Carlsen, in his withdrawal letter, states he isn't trying to get them to make changes, just stating the reason he's finding it hard to find the motivation to prepare. Since several of the reasons he gives are still in force today, I'll let others speculate on which of his issues was paramount.)

**For trivia buffs**:

1. I think Carlsen in 2011 became the first player in history to withdraw from the same championship cycle *twice*. He first withdrew from the Grand Prix cycle, which was supposed to select the majority of the challengers, then was reseeded back into the cycle by virtue of his spot at the top of the ratings list (three slots were for the top 3 finishers in the Grand Prix, the loser of the previous WCC match, the winner of the 2009 World Cup, the highest rated player, the loser of the final candidates match from the previous cycle, and one player nominated by the organizers). FIDE's response was to replace Carlsen with Grischuk -- IIRC, Kramnik was the a qualifier from the GP and *also* the second highest rated so he essentially took Carlsen's spot as the top-rated and his GP qualification went to Grischuk.
2. If you were looking for punishments, FIDE really cannot force *anyone* to play in their events, and rarely (I said rarely but I can't think of single instance offhand) punishes a player for declining to play. Chessplayers are not the slaves of any organization, no matter how much some of politicians in charge want them to be.
> 6 votes

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Tags: history, fide, world-championship, famous-players, carlsen
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title: Differences between FEN and EPD?

text:
# Question
Title: Differences between FEN and EPD?
I just read the description of FEN (*Forsyth–Edwards Notation*) and EPD (*Extended Position Description*), I have a basic idea of what they are, but I still have some points that are not entirely clear:

* What are the main differences between those two?
* When should I use one over the other one?
* Which one is more common to see?

I am trying to decide which one to use for a personal project, and I can't take this jump without knowing everything about them.

# Answer
* What are the main differences between the two?

> Extended Position Description is a standard for describing chess positions along with an extended set of structured attribute values using the ASCII (American Standard Code for Information Interchange) character set. It is intended for data and command interchange among chess playing programs. It is also intended for the representation of portable opening library repositories. The first four fields of the EPD specification are the same as the first four fields of the closely related FEN specification. Like FEN, EPD can also be used for general position description. However, unlike FEN, EPD is designed to be expandable by the addition of new operations that provide new functionality as needs arise. More information can be found at this site.

* When should I use one over the other one?

> EPD is more expandable by the additon of new operations and is more versatile and is used primarily in chess programs. See bullet point one.

* Which one is more common to see?

> Overall, I would say FEN is more common, but this is relative to what you are trying to do.
> 5 votes

# Answer
I'd like to provide some more details. I will answer "bottom up" (last bullet first).

* FEN is indeed much more common, at least, more commonly ***seen*** by "normal users": major online chess sites (chess.com, lichess.org, ...) propose to millions of users at each moment to export the position they're looking at in the FEN format, sometimes also in other formats (including PGN which describes the whole game, as opposed to just the position, with all moves, metadata, possibly analysis with variations and annotations). You will almost never be proposed to share a position in EPD format. However, these same web sites might internally store their opening database and maybe even their entire puzzle database in the EPD format.
* The purpose of the two is different: FEN contains just exactly the minimum information one has to know about the position to continue playing the game. EPD may contain a lot more subjective and also complementary factual information, see below. So, it depends on what you want to store.
* As the name says, EPD is an *extended* position description, and it does extend the FEN format, in a slightly relaxed sense: The first four data fields (Piece placement, Side to move, Castling ability, En passant target square) are exactly the same.

The FEN format then has exactly two more data fields: Halfmove clock, and Fullmove counter. They are specified as two integers following the ep square, and that's what the FEN string ends with. These last two data are not "rigidly" taken over in the EPD format, but implemented through EPD "Operations".

The EPD format has a first part consisting of the above mentioned four main data fields. That part is followed by an arbitrarily long list of so-called "Operations" each of which consist of a mandatory `<opcode>`, followed by zero or more space separated arguments called operands, and a mandatory semicolon `;`.

The `<opcode>` has the form of a lowercase letter followed by at least one and at most 14 more lowercase letters and/or digits and/or underscores `_`. Examples include: `bm` (best move), `ce` (centipawn evaluation), `c0` (primary comment), `fmvn` (full move number: this is the FEN's Fullmove counter), `hmvc` (FEN's halfmove clock), `id` (position identification), `pv` (predicted variation, i.e., continuation), `v0`-`v9` (variation name, e.g., name of openings and their variations) etc.

The operands may be (signed or unsigned, integer or decimal) numbers or strings (enclosed in "...") or moves in SAN (standard algebraic notation, like e4, Nbd2+ or bxc1=Q#, without quotes, and not preceded by move numbers nor '...' when it's black's move, e.g., in `pv`).

It is somewhat surprising that the halfmove clock is not mandatory in the EPD format, although it is necessary to apply the 75 move rule. But we must admit that application of the 3- or 5-fold repetition would also require to know all previous positions - at least, when the last move wasn't a pawn move or capture.

So, in short, the EPD contains annotations and other, possibly subjective data, which might be of interest especially in databases for use in chess programs (Opening database; test cases for program testing, debugging and/or machine learning, etc...). The FEN is just the raw position.

Sources:
> 2 votes

---
Tags: notation, fen
---


title: Question on FEN and castling

text:
# Question
Title: Question on FEN and castling
I was reading about FEN notation, and noticed the following line in the relevant Wikipedia article:

> If neither side can castle, this is "-". Otherwise, this has one or more letters: "K" (White can castle kingside), "Q" (White can castle queenside), "k" (Black can castle kingside), and/or "q" (Black can castle queenside).

Why do we need to mark the ability to castle each side separately? I can't imagine a circumstance where one would be able to castle kingside, but not queenside unless the reason you can't do one is because it would be illegal to castle in one of the directions. But if this is the only reason, why would this need to be documented when recording a game in FEN? Maybe there is something about castling I'm misunderstanding.

# Answer
If one of the rooks has moved from its starting position, it is no longer legal to castle with that rook.

For example, if white plays `1. a4 2. Ra3 3. Ra1`, white can no longer castle long, even though the king and rook are both in their normal positions.

For this reason, the FEN string must encode whether or not castling is legal (because both king and rook can be on the proper squares, but castling can still be illegal).
> 13 votes

# Answer
Yes, this part of the FEN is (**only**!) about whether either of the rooks (or the king!) *****have moved earlier*****, in which case the respective rights disappear (K *and* Q resp. k *and* q, if the king moved).

It is **not** about whether it is legal or not to castle in one or the other direction because of threatened squares. (Note that castling is not only forbidden when the king is in check, but also when *****any of the squares it travels over***** is threatened. This can and usually does also vary between kingside and queenside castling right considerations -- which makes me think that you may have forgotten about that "detail", too. For example, if the square f1 or g1 is threatened by an opponent's piece, then you can't castle kingside, but you may well be allowed to castle queenside.)
> 0 votes

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Tags: castling, fen
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# Question
Title: Software for reading multiple FEN positions
I have started playing around with SCID and Arena to analyze my games and store interesting screenshots. I recently heard about the FEN notation which makes it convenient to describe chess positions (previously I used to store screenshots of the board positions)

Now I know that SCID can read a single FEN string and set up the described position from that string. As far as I understand, it cannot read a file containing multiple FEN positions, and iterate through them.

What I would like to do is keep a database text file with interesting positions from my games, or famous games, or typical opening positions into a single file, one FEN string per line, along with a short comment giving some more context and information about the position.

So the file would be something like

```
1b6/4pKn1/8/1nPkqp1R/2pr3p/3b1pp1/P3Qp2/2BRr3     # comment 1
1B6/4pKR1/3b3p/3QN2p/1Rb2k2/3PpN1P/2q1P3/8        # comment 2
1b6/4pN1K/2qpQ1p1/R4n1p/1Prkb3/N2p1pB1/3P1n1r/8   # comment 3
1B6/4pN1p/7p/3P1k2/2p5/4P2K/4P3/2Q4N              # comment 4

```

Can SCID handle such a file with multiple FEN notations? Or is there some other software for reading such files and allowing me to iterate through the various positions described in that file (and hopefully allowing me to make some edits)

# Answer
A file that contains one FEN per line is a file format in itself. It's the file format used by test positions for chess engines. So engines definitely have some process to analyse all the positions in a FEN file.

(Ermm... your FEN is missing the king-castling, move number and who is to move indicator -- you'll want those.)

An alternative would be to convert each FEN line into a PGN game -- The FEN line goes in the PGN header, e.g. \[FEN "1b6/4pKn1/8/1nPkqp1R/2pr3p/3b1pp1/P3Qp2/2BRr3"\], and the comment can just be a "Before move annotation". So you could construct a minimal PGN game for each position -- and PGN is supported by absolutely every single piece of chess software out there. There is a minimal set of headers required for a valid PGN game, White, Black, Site, and Result. Plus that FEN header.

Scout around, maybe you can find a fen2pgn script. There was one a few decades ago.
> 4 votes

# Answer
You may want to consider the EPD format in order to append any kind of annotation, comment, information... to the "rigid part" of the FEN (which remains the same in EPD, except for the move counters). I read that EPD was officially integrated into PGN, and I know that one PGN file can hold several distinct games, so you should be able to incorporate the FENs into a PGN.

Also, Python now has a `chess` module (see the doc here) which can read (parse) and write (output) FEN, EPD and PGN and also SVG (high-resolution graphic rendering of chess positions). If you need automated processing of a database of FENs, that might be an interesting path: You can simply read in line by line your FEN's (like, `FEN = input()`), use `B = chess.Board( FEN )` to parse it, then modify / extract whatever data you want, and write back the result in whatever format suits your needs.
> 1 votes

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Tags: fen
---


title: Software to create FEN notation?

text:
# Question
Title: Software to create FEN notation?
I am new to FEN notation. I understand its importance for describing position of pieces on board. I also understand FEN notations after reading about it in Wikipedia. However, it is a time taking procedure to write it down manually. I am looking for a software or web site, which allows me to place the pieces on the board, and then create FEN notation automatically.

# Answer
> 7 votes
> I am looking for a software **or web site**, which allows me to place the pieces on the board, and then create FEN notation automatically.

I personally use this site for that.

It is free, and it is **an online tool.**

**REMARKS:**

*If you wish to put that FEN in our diagram you paste that code like this:*

1. Press space bar 4 times;
2. Type square brackets ( `[]` );
3. Type `fen ""` inside the brackets ( `[fen ""]` );
4. Paste your code inside the `""` ( `[fen "Your FEN goes here"]` );

*If you decide to input variations you need to do this:*

5. Press enter twice;
6. Press space bar 4 times;
7. Input moves;

Here is an example:

*If you have further question leave a comment and I will help you. Also read this thread.*

**END OF REMARKS**

Hopefully this answer helps you.

Best regards.

# Answer
> 3 votes
SCID will do it. Create a position using `Edit->Setup Board`. There's a text box at the bottom of the setup window with the FEN. Or, if you've been playing against the computer, you can just say `Edit->Copy FEN` to get the board's current position.

# Answer
> 3 votes
I use the Lichess Board editor. It has drag and drop, and click and place and it provides the FEN to any position.

# Answer
> 2 votes
I´m in a similar matter. But what I tried to have is a fen list, not just a single fen line. That is: having a PGN file, have the complete list of fen, one line per position. If for example the game had 40 moves, I need the 40 positions that ocured during the game.

In fact I found one program that do it: pgn2fen: http://pgn2fen.downv.com/Windows-software-download/pgn2fen It has a bug, it does not make the fen for the last position.

# Answer
> 1 votes
Python has now a `chess` module, which is able to parse FEN (among other formats), and also output any position to FEN, EDP, PGN and also SVG format. It is as simple as `F = input(); B = chess.Board(F)` to read in a FEN. Then you can easily extract information or modify the positions, and write it back to a file using `B.fen(en_passant='fen')` or `B.epd(en_passant='fen', ...)`; to write back a PGN, use `chess.pgn`; see chapter "Writing" of the documentation, similar for producing SVG.

You can find more information at:

---
Tags: fen
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# Question
Title: How is rating score calculated on Lichess?
I've recently lost to a 1500 player. My rating is about 1200. Ironically, he got 163 points. How is it possible for a 1500 player to gain more points on a lower-rated player? The system that Lichess uses to calculate rating scores is very confusing. How is it done?

# Answer
Without the link to player profiles and the game iteself, it is difficult to say for certain exactly what happened.

For one, Lichess starts new users with a rating of 1500.\[1\]

Even if your opponent didn't have a 1500 rating, as double-beep points out Lichess uses the Glicko-2 rating system\[2\] which explicitly tracks the player's **rating**, a **rating deviation**, and a **rating volatility**. The system views a player's rating from a stochastic perspective, as an interval not a single point value.\[1\]

The system will detect and provide a larger rating change in various circumstances including:

* "exceptionally strong results after period of stability",\[3\] or
* after a period of inactivity (it is less certain if rating is still accurate).

The Glicko-2 creator, Dr. Mark Glickman, provides the mathematical formulas for the system.\[3,4\]

**As an example**, consider this classical game on Lichess. At the time of the game, the player with the White pieces had only played 1 rapid game. The system seeded the player (White) with a 1500 rating but annotated it as *1500?* to denote the provisional rating.

References:
\[1\] Chess Rating Systems, Lichess website.
\[2\] What rating system does Lichess use?, Lichess FAQ page.
\[3\] Example of the Glicko-2 System, ME Glickman, 30 Nov 2013.
\[4\] http://www.glicko.net/glicko.html, website by Mark E. Glickman.
> 6 votes

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Tags: rating, lichess
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# Question
Title: What is the best approach when an opponent's queen is in the center and all of their pieces are developed?
I have played several games where my opponent's queen is somehow placed in the center of the board. However, this type of aggressive move positions my king in a dangerous spot. I can't castle because the queen can work with a bishop and provoke a checkmate. My other pieces are vulnerable to an attack because of their early piece development. I keep getting check after check because my king is in the center. It forces me to use my other valuable pieces to defend my king. This will eventually result in allowing my opponent to break my defense and slowly take out my pieces or, even worse, force my pieces to retreat. What is the best approach when this type of situation is encountered?

# Answer
The best approach is to prevent it. If you haven't castled, and your opponent's pieces are developed, you've already made several grave mistakes.

Post your game and we'll review it.

There are a number of openings that are known to result in good positions. Do you know which one you play?

EDIT - @toby ok, for what you do, is learn how to play the Ruy Lopez and Queen's Gambit with white. Learn the Grunfeld and Caro-Kann and play them when you have the black pieces. These are well known and solid openings. They will prevent the situation in which you find yourself.
> 3 votes

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Tags: opening, tactics, queens, development
---


# Question
Title: What are some good podcasts to listen to?
I'm an intermediate player, and I practice chess tactics and play regularly. I'm looking for a good podcast or two to listen to during my day. I don't care if it's a podcast that discusses chess news, tactics, or does analysis of games, I just need it to hold my attention for a while. Preferably something available on an Android or PC.

# Answer
The Full English Breakfast by Stephen Gordon, Laurence Trent, and Macauley Peterson was always fun. It was been discontinued 2 years ago but it might still be worth a look.
> 6 votes

# Answer
Ben Johnson produces a weekly chess podcast called "The Perpetual Chess Podcast".

The format is roughly an hour long interview with a personality from the chess world. As well as top grandmasters he also interviews educators, writers, chess politicians and publishers.

Recent interviewees include GMs Irina Krush, David Navara, Josh Friedel and Paco Vallejo, author GM Genna Sosonko, co-founder of Chessbase Frederic Friedel and chess politicians running in the upcoming FIDE presidential elections GM Nigel Short and IM Malcolm Pein.
> 6 votes

# Answer
Not exactly what you may have asked for but sort of. Here the host interviews a celeb over a game of chess. http://www.bbc.co.uk/programmes/b04njsks/episodes/downloads
> 3 votes

# Answer
You can get a lot out of the Banter Blitz videos (served by YouTube) by Chess24. The link shows an example by GM Jan Gustafsson, but there are other masters offering similar material. Much of the content is free.

You said you weren't particular about the content, but you might find it interesting to know that these videos involve the master explaining what's going on during a blitz game they're playing, and what they're thinking while they play. As a result, you will get advice about openings, learn to spot the kinds of mistakes their opponents make, pick up some endgame theory, and even get some in-game commentary on tournaments, personalities, and history. A very enriching experience, overall.

I find the format where one game at a time is played, start-to-finish, more enriching than the simul display formats that are offered elsewhere, such as at ICC. For one thing, in the simul format the master is often playing as fast as possible, with very little time for talk. On the other hand, in the one-at-a-time format, the master can advise/warn/speculate/muse/babble during the opponent's think time. I find that the content is just richer with this format.
> 3 votes

# Answer
For those looking for Spanish podcasts:

* El Rincón del Ajedrez, 30-40 minutes each, an interesting podcast focused on chess culture, with interviews, chess history, book reviews and so on with Manuel Azuaga. It used to be weekly, although lately it is done every 15 days (maybe summer holidays).
* COOLtura de Ajedrez, another good podcast, 1 hour each, with chess news and some good interviews. Chess news are mainly about catalan chess, but major national and international tournaments are treated too.
* Xarxa de Mat, another weekly 1 hour podcast very similar to COOLtura de Ajedrez, but in this case language is Catalan.
> 2 votes

# Answer
This could use some updating. With chess becoming more popular during the SAR-COV-2 pandemic and also from the ***Queen's Gambit*** miniseries, chess podcasting has exploded in the past couple years.

Already mentioned in another answer, the Perpetual Chess Podcast is the best podcast I know of that is currently (December 2021) in continued production. It has now been going for over 5 years, with weekly interview pods. There are also separate book reviews most months. Recently there were special releases during the World Championship match.

US Chess has four different podcasts:

* Lady's knight: features women in chess
* Cover Stories: discusses the cover story from that month's issue of ***Chess Life***
* Underground: "explores eccentricities, peculiarities, and theoretical novelties."
* One move at a time: about people and organizations promoting chess in the US (and US Chess' mission)

Chess Journeys is another podcast I enjoy regularly. It is a series of interviews with adult improvers of all levels.

Premier Chess Podcast: TBH, I find this one uneven. Sometimes the guests are - at best - only tangentially related to chess. I don't listen a lot, and usually skip the episodes that don't look chess related.

Another one I have listened to is The Chess Pit, where - as their tag line goes - "three guys talk about chess ... occasionally". They also covered the Carlsen-Nepomniachtchi match, with discussions of the games on a daily basis. (Update: As of early July, 2023, The Chess Pit hasn't been producing new shows regularly for the past several months, although they did produce some shows during the Ding-Nepomniachtchi match. As such, I've moved it to the bottom of the list.)

There are many more, but in the interest of time and space I will stop here.
> 2 votes

---
Tags: analysis, learning, tactics, recommendations
---


# Question
Title: Why did Bobby Fischer make his demands in the 1975 World Chess Championship?
Many topics ask about Fischer's demands in the 1975 World Chess Championship between him and Karpov, but I've never found the reason Fischer made these demands.

In particular:

> If the result is 9-9, then the title goes to Fischer but the prize money is split equally.

Clearly, this gives Fischer an unfair advantage, so how did he think it was okay to request? Fischer dominated Spassky, and his chances of winning seemed good -- so it appears he didn't need to give himself any kind of edge. So why did he want it?

# Answer
Fischer had a history of making (often considered unreasonable) demands and refusing to play if not met. The reasons for this is a source of speculation amongst chess historians which has not (and probably may never) be settled conclusively. It is probably safe to assume that there is a psychological component at play, which is always hard to pin down.

"Bobby Fischer Against The World" illustrates many of these occurrences as well as some opinions by contemporaries and modern players. If you have not done so I suggest you check it out and make up your own mind (I think it's freely availabe on Youtube)

Just for clarity, the 9-9 rule by itself was not really the issue - many championship matches were played with the rule that on a draw the champion maintains his title. It is when combining it with the "unlimited games until whoever reaches 10 first wins" where the problem arises - for Karpov to win he would have to win 10-8, since 9-9 would not give him an opportunity to play to win 10-9. I don't think many people blamed FIDE for refusing that demand.
> 6 votes

# Answer
Fischer wanted a return to earlier days in chess. Capa-Alekhine was an unlimited match to six wins. In some 19th century events, the rule was if the game was drawn, reset the pieces and play another. This is the rationale behind the request ("If this was good enough for Alekhine, why shouldn't I have it, too?")

My own opinion is that Fischer knew he was not in good playing shape, having not competed for three years, so he wanted a longer match so he could "play himself into shape," so to speak. (Something like this actually happened in the first Kasparov-Karpov match, where Kasparov was clearly inferior to Karpov at the beginning of the match, but built up his strength and technique through the games until becoming at least Karpov's equal by the end, if not superior.)

The Capablanca-Alekhine 1927 match showed the folly of unlimited matches (34 games, 25 draws) so that format disappeared from the chess scene until Karpov-Kasparov.

There have always been arguments over the World Champion's edge. Early champions got to pick who they would play a match against, leading to many good players never getting a shot at the title. The "London Rules" tried to put a stop to that, but it still required the challenger to put up a large sum of money, thus limiting challenges.

In the FIDE era, the champion often had a huge edge. Mikhail Botvinnik was champion a long time without ever once winning a match in defense of his title. He drew two matches, retaining the title by "draw odds," and lost all the rest, only "retaining" the title as a result of winning the mandatory return match the following year. In 1963 FIDE dropped the return match provision, and Botvinnik, after losing to Petrosian, stopped contesting for the title.

Botvinnik played with both "draw odds" *and* the return match, champions from there until the latter half of the 20th century only had draw odds, and that revealed the champions were often not as clearly superior as the record seemed to show to that point, as only Petrosian succeeded in defending the title (once, against Spassky, before losing the following cycle to Spassky) until Karpov.

I don't know why the unlimited match returned, but I suspect it was because non-soviet chess was becoming stronger, and might challenge their hegemony that the match rules got adjusted. And the first Karpov-Kasparov match showed us again why an unlimited match is a Bad Idea. And the return match clause merely added to the debacle.

The tradition of chess is that you have to dethrone the king, not merely match him, to take the crown. (Even the metaphors shout monarchy.) This is unlike pretty much every single individual sport on the planet; typically the defending champion has to engage all the challengers and prove they belong at the top (boxing being the lone exception I can call to mind ATM). So I doubt the challenger will ever be faced with a completely level playing field. (FIDE tried earlier, by creating a knockout tournament of short matches, but that met with a great deal of resistance from the players, and was dropped. And even in it, the playing field was tilted by seeding some players directly into the later rounds of the event.)
> 3 votes

# Answer
This is simply a variation of the common "if votes are split 50-50, the status quo prevails" kind of tiebreaking mechanism. Sometimes you even need a supermajority to effect changes.

In chess - at least in Fischer's interpretation - this means that if you want to become world champion, you need to *beat*, not just tie, the previous champion.

Note the 9-9 clause has some support among other chess players, most notably Korchnoi:

> Was Fischer right in demanding that the world title be protected by a two point handicap – that the challenger would be considered the winner with a 10–8 score and that the champion would retain his title in the event of a 9–9 draw? Yes, this was quite natural: the champion deserves this, not to mention the fact that further play to the first win in the event of an even score would be nothing short of a lottery – the winner in that case could not claim to have won a convincing victory.
> 3 votes

---
Tags: history, world-championship, fischer, 1972-world-championship
---


# Question
Title: Why does chess.com consider this promotion a blunder?
I've just played a game on Chess.com, and I'm surprised that the engine considers a promotion that I made a huge blunder. Like, my position was rated -62.8 (basically a won game), and after I promoted my pawn to a queen the rating dropped to -6.40. That's more than 50 points with a single move!
This is the position:

```
[FEN "8/8/2B5/p7/8/p4p2/P2K1kp1/8 w - - 0 1"]

1. Be4 g1=Q (1... Kg3 2. Kd3 g1=Q 3. Kc4 f2 4. Bd3 f1=Q 5. Bxf1 Qxf1) 2. Bxf3 Kxf3 3. Kc2 Qc5+ 4. Kd3 Qb5+ 5. Kd2 Qb2+ 6. Kd1 Qxa2 7. Kc1 Qb2+ 8. Kd1 a2 9. Ke1 a1=Q# 0-1

```

I played g1=Q, but the engine says I should have played Kg3 instead, which would have kept the rating at -62.8. I don't understand why. My pawn in f3 was threatened by the bishop, but it was protected by the king. The white king was unable to come closer, because of my king. And the pawns on the left were irrelevant.

The engine's move did lead to another pawn being promoted... Only to be captured by the bishop, which in turn was taken by the first queen. So after a few moves the situation was identical: king and queen vs king (plus the pawns on the side). And even with my "blunder", winning was easy.

Why does the engine find such a huge difference? Should I just ignore this, or am I missing something important?

# Answer
50 points sounds huge, but there actually is no meaningful difference between -6.4 and -62 in such an endgame.\*

* 6.4 is more or less "Black has a queen for a bishop (but I haven't found a way to make progress yet)"
* 62 on the other hand is "I *have* found that way to a position that is 100% won (but I haven't found a forced mate yet)"

Why does the engine rate both moves differently? That might just come down to random chance: Since Black has a winning position either way, almost all moves along the calculation tree are equal to the engine's eye and it loses its guidance so to speak which branches are best to pursue. At the same time, the tree is still relatively big (White has a lot of ways to shuffle the bishop around, etc.). So the tree gets deepened in one more or less random direction and the engine will keep expanding from there (downwards and sideways) because all moves it finds are keeping the advantage.

By chance, the trees for 1...Kg3 and 1...g1=Q start growing a bit differently. They will of course converge eventually (to the mate in 11 Allure mentions) if the engine gets enough time to calculate all of the tree. But in for example automatic game analysis, it often doesn't (20-30 seconds for all moves = not a lot of time per single move). In this case, the search for both moves just happened to be cut off at different states of incompleteness (with different temporary evaluation scores).

Which is a bit annoying if it taints your statistics for an otherwise well played game - but you can safely ignore it.

\*For this reason, at least Lichess internally caps the scale at +10 and -10 so that a drop from -60 to -10 would not be labelled a "blunder". Don't know how chess.com handles this, maybe the drop from -6.4 to -10 was still enough for a "blunder" though.
> 30 votes

# Answer
This sounds like a bug. Using Lichess's analysis engine, it takes Stockfish 14 less than ten seconds to find a mate in 11 moves. Both 1...Kg3 and 1...g1=Q lead to mate in 11.

So there should be no difference in which move you start with, even objectively (of course as a human I'd go 1...g1=Q without thinking).
> 23 votes

# Answer
So, -60 to -7 is not as big as a blunder as you may think

+/- 60 points basically means Team A’s got it set up but is waiting for the opponent to blunder mate.

+/- 7 Points is a Queen for 2 Pawns at the start.

NOT that big of a blunder.
> -1 votes

---
Tags: engines, analysis, endgame, blunder
---


# Question
Title: Why does white exchange knight for a pawn here?
This other question asks about why white resigns at the end (Why did Polgar resign?), but running through the game, I am confused at move 49 where the board looks like this, white to move:

**Polgar-Kasparov:**

```
8/8/1k6/p6p/3n3r/PNR5/6K1/8 w KQ - 49 50

```

The next move is white to take the pawn with her knight, and have the knight taken by the king. Since the knight would be lost, why not take the black knight instead?

# Answer
**After taking:**

```
8/8/1k6/p6p/3r4/P1R5/6K1/8 w KQ - 49 50

```

Judith Polgar must have assessed this position to be easily winning for black. I assume black would just win the white pawn and proceed to promote the a-pawn.

Now, while a knight is generally worth much more than a pawn, the endgame King,Rook,Knight vs King,Rook is usually a draw. So Polgar must have hoped to win or blockade the h-pawn and reach a drawn endgame of the K,R,N vs K,R-variety. I guess she knew this wouldn't work out, but the rationale was to set a more difficult technical task to Kasparov than the above rook endgame.

Edit: I looked up the game in her autobiographical best games collection and it turns out, I was half right:

"Following the text move, the rook ending after 50.Nxd4 Rxd4 would be lost for me. Black would advance his pawns to my fourth rank and then activate his king using the rook as shield."

She then proceeds to give 50.Nxa5 an exclamation mark, explaining that it is a study-like way to a draw, because apparently she wins the black pawn by force (which I didn't see).

So, she did assume the rook ending to be lost (erroneously, according to Stephen's comment), but she actually saw that she would win the h-pawn as well, leading to a drawn endgame.
> 6 votes

# Answer
Pawns are OP in the endgame, because you can promote them to basically whatever you want (Except a King, but still)

Knights will, erm, always be knights. Plus, the only way knights can mate is when the opponent king is trapped, which does not happen when there are grandmasters and little pieces on the board. Queens, however, can mate in a ton of ways
> -3 votes

---
Tags: analysis, endgame
---


# Question
Title: Is blocking a check with a check an illegal move?
Say my opponent puts me in check. If I move my queen to block the check and it also puts my opponent in check, is that legal?

# Answer
> 11 votes
Yes, it is legal, since your king is no longer being attacked.

# Answer
> 3 votes
It is legal to block a check with a move that also gives check. This includes the case you ask about, where the blocker is a queen; this is a key tactic in queen endings.

In general, a move that simultaneously parries a check and gives check is called a cross-check. This can happen with any of the three ways to parry a check:

+ The King can move, discovering check;
+ the checking piece can be captured, giving either direct or discovered check; or
+ the check can be blocked, again with either direct or discovered check.

Tim Krabbé cites two tournament games (Zarrouati-Brauckmann, Toulouse 1990; Cardona-Conejero, Mislata (Spain) 2003) each featuring a sequence of six(!) conecutive checks, and thus five consecutive cross-checks. These show four of the five kinds of cross-check listed above (including one where a Queen move both blocks and gives check, as **John** asked). The fifth kind, a block that discovers check, is illustrated twice in G.F.Anderson's 1919 problem cited on Wikipedia's "cross-check" page, and five times in the 1961 problem by the same G.F.Anderson — including three cases where the cross-check is both direct and discovered, i.e. a double check.

# Answer
> 2 votes
It is absolutly legal. A fun lichess study even did it some times: https://lichess.org/study/1LK3rCAK (it happened 5 times if I counted correctly, but not a lot with the queen :) )

# Answer
> 1 votes
Yes, that move even has a proper name called cross-check

Nowadays most chess programs/apps/websites implement complete FIDE rules. A quicker way to check might be to set up the board that reflects your case, and see if the program allows you to move that way

# Answer
> 1 votes
It is indeed, allowed for you to do that. Because, your king is not being attacked and according to the chess rules, if your king is not being attacked, you are allowed to do anything to stop the check. When you put your queen in front of your king to block checks, you are basically defending your king. Thus, according to the rrules, it is allowed and I think it is encouraged because you are protentually putting your enemy's king in danger while protecting your king at the same time.

# Answer
> 0 votes
It is legal to block the check in a way which puts the opponent in check.

The rule is easier to understand with some history. One can think of chess as a game which ends when one captures the enemy king. Indeed, there are some variants of Chess which do end this way. However, historically it was *highly* frowned upon to think about capturing a king. Capturing a queen was bad enough, but kings were not something a peasant just went around capturing. And so, the game of Chess evolved to not capture the enemy king. Instead, we reach the point where capture of the enemy's king is imminent inevitable, and then stop.

If you block the check with another check, then the capture of your king was not inevitable. You had a way out.

Think of it like a nature documentary, which cuts away from the wolf chasing the cute baby deer right at the moment where the baby deer's capture is inevitable. Everybody knows what happened, but we don't like to show it.

---
Tags: rules, check, illegal-move
---


title: Where can you play against AlphaZero?

text:
# Question
Title: Where can you play against AlphaZero?
I have read a few articles about the game between Stockfish and AlphaZero. But is there a place where anyone can play against AlphaZero?

# Answer
As already explained by other answers, AlphaZero itself is not publicly available.

The community has created Leela Chess Zero, a chess engine that started by using the same basic concepts as AlphaZero, but has since seen many additional improvements. It's probably stronger than AlphaZero ever was. Their site has a page on how to play against it, either download it or play against one of the lichess bots.

As a side note, stockfish has also been improving steadily (mainly with the introduction of NNUE), so it should now also be able to beat the original AlphaZero version again.
> 31 votes

# Answer
No, you can't play against AlphaZero, unless you get a special access from DeepMind.
> 13 votes

# Answer
According to this website, AlphaZero was one of the strongest chess engine and defeated Stockfish (28 victories, 72 draws, and no losses). It runs on Google's supercomputer and is developed by DeepMind. There is no website which currently supports this type of chess engine. As discussed on the answer above, you'll have to get special permission from DeepMind to play against it. So, the answer is no. Read the article that I've linked on the top of this post for more information about its history, development, and impact in the chess world.
> 13 votes

---
Tags: engines, websites, alphazero
---


# Question
Title: What is white's increased advantage in chess90 as compared to chess870? (Chess960 can be split into 2 subsets, chess90 and chess870)
Here, it is shown 90 of 960 positions involve having to move a rook on 1 side in order to castle on the other side (unless the rook is somehow captured or something). These 90 positions come from 18 rearrangements/permutations/combinations/whatever from each of 5 groups of starting positions (SPs)

1. RKRXXXXX
2. RKXRXXXX
3. XRKRXXXX
4. XXXXXRKR
5. RXKRXXXX

Based on the Sesse evals for the 960 SPs (see here also) or based on other similar sources (such as practical instead of theoretical statistics like win rate eg this (computer chess) \[again see here\]), what is white's increased advantage in chess90 compared to chess870?

Note 1: This can't be vacuous. If white actually has a bigger advantage in chess870 compared to chess90, then the answer is simply negative.

Note 2: I'm answering below for the sesse evals. I have yet to answer or receive an answer for the computer chess statistics.

# Answer
> 0 votes
Group of SPs and then average evaluation (rounded to 4 decimal places):

1. RKRXXXXX - 0,1900
2. RKXRXXXX - 0,1906
3. XRKRXXXX - 0,1878
4. XXXXXRKR - 0,2017
5. RXKRXXXX - 0,1867
6. Whole of Chess960 - 0.1801
7. Whole of Chess90 - 0.1913
8. Whole of Chess870 - 0.1790

Therefore,

(0.1913-0.1790)/0.1790 = 0.06871508379 ~ **6.87%, almost 7%.**

---

**Remarks**:

1. Chess960 has a higher evaluation than chess870, but only by (0.1801-0.1790)/(0.1790) = 0.00614525139 ~ 0.6%.
2. Chess90 and each of its 5 SP groups have an average evaluation higher than the average evaluation of both chess960 and chess870.
3. SP 518 is 0.22, which is higher than each of the 8 evaluations.

---

In case you want to verify for yourself, here are my google sheet codes for the 5 SP groups of chess90:

1. RKRXXXXX - `=IF(LEFT(B2;3)="RKR";1;0)`
2. RKXRXXXX - `=IF(AND(LEFT(B2;2)="RK";MID(B2;4;1)="R");1;0)`
3. XRKRXXXX - `=IF(MID(B2;2;3)="RKR";1;0)`
4. XXXXXRKR - `=IF(RIGHT(B2;3)="RKR";1;0)`
5. RXKRXXXX - `=IF(AND(LEFT(B2;1)="R";MID(B2;3;2)="KR");1;0)`

---
Tags: chess-variants, statistics, castling, mathematics, chess960
---


# Question
Title: What should be my move as white and what kind endgame should i target?
I played this game with an AI. I played brilliantly till this position presented itself.

# Answer
> 2 votes
Lichess: 1r1q2k1/1p4b1/1n2p1p1/p3Pr1p/P2PRP1P/R1P5/1P6/3Q2K1 w - - 0 1

There's not really any hope here unless black is down a lot of time, and there's no increment or something.

White is down 2 pawns for 2 minor pieces. Maybe just 1 pawn for a minor piece is a little manageable but when it's 2 for 2, nothing really to be done.

Theoretically though, I wouldn't mind playing king and 2 pawns vs king, bishop and knight.

---
Tags: endgame, strategy, counterplay
---


# Question
Title: A classical Rook vs Bishop endgame (with pawns)
Karsten Müller and Lamprecht give the following ending as a win in Fundamental Chess Ending. However, Houdini 6.02 does not find a win as far as I analyzed.

```
[FEN "R7/5pkp/4b1p1/3p4/8/5P2/5KPP/8 b - - 0 1"]
[startflipped ""]

```

What happens with perfect play?

# Answer
> 3 votes
This position is example 7.57 on page 285 - chapter ROOK VS MINOR PIECE(S): **R. Dautov - T. Heinemann** *German Ch. (Bremen) 1998*. I was able to find that game online on Chess Tempo and on Lichess:

```
[Event "70th ch-GER"]
[Site "Bremen GER"]
[Round "9"]
[Date "1998.11.14"]
[White "Dautov, Rustem"]
[Black "Heinemann, Thies"]
[WhiteElo "2625"]
[BlackElo "2495"]
[Result "1-0"]
[FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]
[StartPly "85"]

1.d4 Nf6 2.c4 c5 3.d5 b5 4.Nf3 bxc4 5.Nc3 d6 6.e4 g6 7.Bxc4 Bg7 8.e5 dxe5 9.Nxe5 O-O 10.O-O Ne8 11.Re1 Nd6 12.b3 Qc7 13.Bf4 Nd7 14.Nxd7 Qxd7 15.Be5 Rb8 16.Qe2 Bxe5 17.Qxe5 Rb4 18.Ne4 Nxc4 19.bxc4 Rxc4 20.d6 Rxe4 21.Qxe4 exd6 22.Rad1 Bb7 23.Qe7 Qc6 24.f3 d5 25.Rb1 Bc8 26.Qxa7 c4 27.Qd4 Be6 28.Rb6 Qc7 29.a4 Rc8 30.a5 Qa7 31.Ra1 c3 32.Rb4 Qa6 33.Qb6 Qd3 34.Qd4 Qa6 35.Rb3 Qc4 36.Qxc4 Rxc4 37.a6 c2 38.a7 c1=Q+ 39.Rxc1 Rxc1+ 40.Kf2 Ra1 41.Rb8+ Kg7 42.a8=Q Rxa8 43.Rxa8 h5 44.Ke3 Kf6 45.Kd4 Kf5 46.g3 Kf6 47.Ra3 Kf5 48.Re3 Kf6 49.Re5 Ke7 50.Kc5 Kd7 51.Re3 Ke7 52.Rd3 Kf6 53.Kd6 Kf5 54.Rd4 g5 55.h4 Kf6 56.hxg5+ Kxg5 57.Ke5 Kg6 58.Rb4 Kg7 59.Rb8 d4 60.Kxd4 Ba2 61.Ke5 Bc4 62.Kf5 Bd5 63.f4 Bf3 64.Rb6 Bg4+ 65.Kg5 Bf3 66.f5 Bg4 67.f6+ Kh7 68.Rb7 Be6 69.Kxh5 Bd5 70.Rb4  1-0

```

The example, according to the book, demonstrates the difficulties a bishop faces in general (even with an extra pawn!) against a rook. After 43... h5!? 44. Ke3 Kf6 45. Kd4 Kf5?! 46. g3 Nf6, the book analyzes some variations that could occur if 46... h4!? was played.

55. h4! is the finishing touch: it creates more weaknesses on the dark squares. Black has lost.

---

While it might be feasible for an engine to draw (playing black), it's almost impossible for a human to make no mistakes, as these positions are too tricky. The more the pawns on both sides the greater the superiority of the rook and the better the chances to win.

---
Tags: engines, analysis, endgame
---


# Question
Title: On average, how many pawns are there at the start of the endgame?
**Question**: On average, how many pawns are there at the start of the endgame?

To answer:

1. You can choose your definition of the endgame as long as you can show a credible reference that supports your choice of definition. What I have in mind is the same as lichess which I understand to be 6 or fewer non-pawn and non-king pieces.
2. You may answer for both sides total (e.g., 10 pawns total on average) or for just 1 side (e.g., 5 pawns per side on average).
3. As to the sample...maybe the same/similar sample from which 38 moves average was obtained.

* 3.1. **You can pick your own sample** like, say, all standard world championships except 2021. Or 21st century standard world championships except 2021

What I tried:

* Checking out some of my recent games on lichess (that reached the endgame), I see a lot of my games have at least 10 pawns. A few of my games have 6 or lower though. I estimate the average is at least 10 pawns.

Little context:

* I think choker has too few pawns, relative to start of the endgame of regular chess/9LX. I want to verify/disprove this conjecture by seeing the average in actual games. In particular, choker seems to have, on average, 5 pawns total for both players. This is about half what I think the average for start of endgame in regular chess/9LX is.
* **Alternative question**: Is the average number of pawns probably significantly greater than 5 (total, not per player)?

# Answer
> 3 votes
for all games in magnus carlsen world standard and world fischer random chess championship matches (basically all world championship matches except world rapid and world blitz)

---

**Average throughout all championships**:

for all: (13+10+11+12+10+12+8+14+11+14+14+13+12+12+14+10+12+12+9+9+10+14+12+12+14+11+12+13+12+11+6+16+15+14+12+14+8+10+9+12+11+10+10+10+14+7+5+12+14+14+14+12+9+6+12+5+11+10+8+6+11+9)/(4+2+4+11+11+12+10+8)=11.1129032258... ~ 11.11

for all classical (and thus excluding 9LX huhu): (13+10+11+12+10+12+8+14+11+14+14+13+12+12+14+10+12+12+9+9+10+14+12+12+14+11+12+13+12+11+6+16+15+14+12+14+8+10+9+12+11+10+10+10+14+7+5+12+14+14+14+12)/(11+11+12+10+8)=11.5769230769... ~ 11.58

for all rapid including 9LX: (9+6+12+5+11+10+8+6+11+9)/(4+2+4)=8.7

for all rapid excluding 9LX: (11+10+8+6+11+9)/6 = 9.1666666666... ~ 9.17

---

**Average by championship**, rounded to 2 decimal places:

| Championship | Average |
| --- | --- |
| 2021 vs nepo | 11.73 |
| 2019 vs wesley (which was all rapid) | 08.00 |
| 2018 vs fabi (classical only) | 11.55 |
| 2018 vs fabi (classical and rapid) | 11.38 |
| 2018 vs fabi (rapid only) | 10.50 |
| 2016 vs sergey (classical only) | 12.33 |
| 2016 vs sergey (classical and rapid) | 11.38 |
| 2016 vs sergey (rapid only) | 08.50 |
| 2014 vs vishy | 10.60 |
| 2013 vs vishy | 11.50 |

**Remarks**:

1. the lowest average in all these (8 pawns) is the 1 that magnus lost namely to wesley so in 2019 fischer random world championship. of course all those games were rapid.
2. Lowest in classical only is 10.60 in 2014 vs vishy. the 3 rapid only entries are all below 10.60: they are 08.00, 10.50 and 08.50. I guess pawns have a higher mortality rate in rapid compared to classical.

---

2021 vs nepo

https://lichess.org/study/1NIB7sSp

1 - 13

2 - 10

3 - 11

4 - 12

5 - 10

6 - 12

7 -

8 - 14

9 - 11

10 - 14

11 - 14

average: (13+10+11+12+10+12+8+14+11+14+14)/11=11.727272...

---

2019 vs wesley

https://lichess.org/broadcast/fischer-random-championship-finals-game-1/-/DM0hC3u1

1 -

2 -

3 - 12

4 -

5 - N/A

6 - N/A

average (all rapid): (9+6+12+5)/4=8

---

2018 vs fabi

https://lichess.org/study/fCum15PU

1 - 13

2 - 12

3 - 12

4 - 14

5 - 10

6 - 12

7 - 12

8 -

9 -

10 - 10

11 - 14

12 - N/A

T1 - 11

T2 - N/A

T3 - 10

average (classical only): (13+12+12+14+10+12+12+9+9+10+14)/11=11.545454...

average (classical and rapid): (13+12+12+14+10+12+12+9+9+10+14+11+10)/13=11.3846153846...

average (rapid only): (11+10)/2=10.5

---

2016 vs sergey

https://lichess.org/study/vENPCM25

1 - 12

2 - 12

3 - 14

4 - 11

5 - 12

6 - 13

7 - 12

8 - 11

9 -

10 - 16

11 - 15

12 - 14

T1 -

T2 -

T3 - 11

T4 -

average (classical only): (12+12+14+11+12+13+12+11+6+16+15+14)/12=12.3333333333

average (classical and rapid): (12+12+14+11+12+13+12+11+6+16+15+14+8+6+11+9)/16=11.375

average (rapid only): (8+6+11+9)/4=8.5

---

2014 vs vishy

https://lichess.org/study/nurfx2OL

1 - 12

2 - 14

3 -

4 - 10

5 -

6 - 12

7 - 11

8 - 10

9 - N/A

10 - 10

11 - 10

average: (12+14+8+10+9+12+11+10+10+10)/10=10.6

---

2013 vs vishy

https://lichess.org/study/9xUbdEqD

1 - N/A

2 - 14

3 -

4 -

5 - 12

6 - 14

7 - 14

8 - 14

9 - N/A

10 - 12

average: (14+7+5+12+14+14+14+12)/8=11.5

# Answer
> 0 votes
It is impossible to predict the number because there are more possible outcomes in chess than in any other game I can think of. When you play in the first 15 moves "most" games will lose 2-4 pawns and at the end of a game with Grandmasters or Masters, the number can range from 4-2 pawns on the board because they tend to sacrifice the pawns for an advantage. But for 1 advanced player and one beginner player you could end up having 6 pawns on both sides because the beginner player will most likely lose in fewer moves than 2 advanced players. If 2 beginner players are playing it could go from 5-8 because they tend to play quicker and not spend time analyzing the board.

Some people define the endgame as the last 5 pieces while come define it as the last 10-20 moves or when one player has a major advantage. When you say average you have to count all if not most of the possible outcomes so you should the number depends on the type of player (defensive or attacking), Strength of player (Rating), Time control (5 min, 30 min, 1 hr). Many GMs play defensively, and many beginner players prefer attacking their opponent's pieces. So there is no real definite answer but it depends on what kind of player you play.

# Answer
> -1 votes
Not on average, but in general, there are 1 to 6 pawns in the endgame (7 and 8 excluded because that is statistically impossible.

---
Tags: endgame, statistics, pawns
---


title: Where to download fischer random games?

text:
# Question
Title: Where to download fischer random games?
Where can I download the PGN files for the World Chess 960 championship from 2019, that was won by Wesley So?

I can view the games on the website e.g, https://www.frchess.com/stream but I want to download the games onto my own machine. pgnmentor and chessgames do not seem to have recorded these games (only "classical chess" games)

# Answer
> 5 votes
The goto site for downloadable pgns for regular chess is Mark Crowther's "The Week in Chess". The good news is that he also covers 960 or Fischer Random. This is TWIC's page for the World Fischer Random Chess Championship 2019.

The link for the pgn files is here.

# Answer
> 0 votes
Semi-finals and finals:

You can try looking up 'chess960', '960' , '9LX', 'chess9LX', 'chess 9LX', 'chess 960' or 'fischer random' in lichess studies

https://lichess.org/study

for example you can find the 2019 FIDE fischer random world championship finals here

https://lichess.org/broadcast/fischer-random-championship-finals-game-1/-/DM0hC3u1

eg

i counted number of pawns at start of endgame for each of the finals games

https://lichess.org/broadcast/fischer-random-championship-finals-game-1/-/DM0hC3u1

1 -

2 -

3 - 12

4 -

5 - N/A

6 - N/A

---

Quarter-finals:

They were played on chesscom

https://www.chess.com/games/archive/gmwso?gameOwner=other\_game&gameType=live&gameTypeslive%5B%5D=liveChess960&endDate%5Bdate%5D=10/31/2019&startDate%5Bdate%5D=10/01/2019&timeSort=desc&opponentTitle=any

---
Tags: chess-variants, pgn, chess960
---


# Question
Title: Does the strength of computers invalidate fears that chess is "too easy", etc.?
Many years ago, I think it was Capablanca who said chess was too easy and I think also, long before computers could play a decent, the "draw death" of chess was discussed.

But can't Stockfish beat any human? Even if the world champ humans has white and sets out to draw, I believe (based on rating) Stockfish still wins with black.

If Magnus Carlsen can't manage a draw with white against the best computer, could it be that the problem is that there is something fundamental about chess that humans do not yet know? The draw death might be permanent or maybe some human genius, perhaps assisted (maybe almost certainly assisted) by a special chess coach AI will discover a way to play chess much better than humans currently do.

I would guess some very bright grandmasters are trying to analyze the games of the best programs, and maybe already some ideas have been overturned.

For example, have computers given us a more nuanced understanding of the value of two bishops or the relative value of pieces? It seems pretty plausible (I have been away from chess for many years) that the piece value of 9 for a queen has changed -- it was just a guess anyway, wasn't it?

# Answer
> 5 votes
Define "understand" ;-)

Humans are notorious information compressors. Just take a very simple chess example: KR/K. Countless times, as a trainer, I explained two methods to mate: boxing in and check while in opposition. Both are simple enough to be learned by a total beginner. Add a few rules of thumb to cover special cases (stalemate and so) and yes, they "understood" KR/K.

But now take a tablebase of KR/K. The shortest mate usually is a combination of both methods. No shortcuts! Thus, it would be quite tough for a human to (quite pointlessly) learn this because it is just a big heap of information that won't fit into working memory. And when it comes to, say, KRN/KNN, we're way over our limits.

My verdict thus is that the statements "chess is easy" and "chess is hard" are not mutually exclusive (remember the Indian saying that a gnat can bathe in it and an elephant drown?) but merely ill-defined by using "chess" pars pro toto: Yes, chess is easy enough that a super grandmaster can hold a draw 99.9% of the time against a colleague without risk if inclined so, but chess is hard enough that the computer will clobber the super grandmaster. Context matters!

Further sidenotes:

* The style of, say, Alpha Zero is not ineffable per se, and in fact, the book "Game Changer" exactly tries to explain it in human terms.
* "Q=9P" is "nowhere" coded in Alpha Zero. A neural net doesn't work this way, there is no "master neuron" to fiddle with and set the connection strengths to the equivalent of 8P! And I daresay it's even impossible to find out, because you merely can enter positions Q+X vs. 9P+X one by one and ask Alpha Zero to assign them, and as each position will have additional individual properties, you can't really isolate the material aspect.

---
Tags: draw, computer-chess
---


# Question
Title: Is it bad etiquette to decline a draw offer when participating in a simul?
On LiChess, FM knightprince gave a simul where I participated (our game). I ~~blundered a pawn~~ played a pawn gambit, but managed to complicate things and won it back. Afterwards, the game would have led to a drawn endgame.

The FM offered a draw; I wanted to refuse, but thought that would be perceived as ungrateful, so I accepted. I wasn't expecting to win; I just wanted to play out the endgame for the experience.

**Question**: Is it bad etiquette to decline a draw offer when participating in a simul?

# Answer
No it's not bad etiquette at all. A player being higher rated does not entitle them to automatically get the result they want, even if the position seems to indicate such a result.

And in the rare case your opponent gets offended by this, congratulations. You've just gained a psychological edge.
> 54 votes

# Answer
It is absolutely not bad etiquette. If you do accept a draw, then you might regret it. Look at this kid's endgame against Wesley So in this South African simul (lichess for the position).

FEN: 8/6k1/6n1/p5P1/7P/8/2B1K3/2b5 w

```
[FEN "8/6k1/6n1/p5P1/7P/8/2B1K3/2b5 w - - 0 1"]

```

Look at not just the current position, but even the previous position. Black had just played Ne5g6. Look at the evaluation in of the previous position!

On the other hand, you may end up like Misha Osipov vs Anatoly Karpov.

I myself think to ask a separate question like 'Is it bad etiquette to ask for the move to be made?' or 'in a simul should draw offers be made *with* a move?'
> 3 votes

# Answer
In the game linked in the OP, play would have likely continued 16...exd5 17.exd5 Nxd5 18.Nxd5 Bxd5 19.Rfd1. Black can try 19...Bb6, although the chances to create anything serious against the doubled b pawns are slim.

However, a simul is a team game. Accepting a draw means there is one less board for the strong player to think over. As a consequence, one should avoid accepting draws in simul games when the position is not a dead draw. I would argue, if anything, that *accepting* a premature draw is against etiquette *towards your teammates*. Of course, there is a balancing act - one more board is always good for the team, but playing on K+R vs. K+R as a time-burner board is quite rude.

Whether the OP’s position qualifies as a dead draw is not clear to me. I would certainly have played on a couple more moves, as I do not see much danger for Black after 19...Bb6, but taking the draw was probably reasonable as well.
> 2 votes

---
Tags: etiquette, simultaneous
---


# Question
Title: How can you deal with gambits/traps opening, assuming you don't know the theory of the opening yet?
For example, the Danish opening:

```
[FEN ""]
1. e4 e5 2. d4 exd4 3. c3 dxc3 4. Bc4 cxb2 5. Bxb2

```

where basically, White gives up two pawns for positional play. And if you don't know the theory, you can lose by falling into traps.

So, how can you deal with this kind of gambits/traps opening, when you don't know the theory?

# Answer
> 9 votes
There are two approaches, accept the gambit or decline the gambit.

1. Accept the gambit. Follow the usual best practices for calculating paying special attention to safety checks.
2. Decline the gambit. Here 3. ..d5 instead of 3. ..dxc3 looks like a great move and probably what I would play.

Here is a thread on thought process / calculation that I recommend

What thought process should one use to find candidate moves?

# Answer
> 1 votes
You lose, basically. Assuming opponent is familiar with the theory and you aren't, then a single misstep will lose you the game. **Don't enter sharp lines if you don't know the theory**.

If you are already in the sharp line, then the safest play is to avoid the most critical continuations and seek to simplify the position as quickly as possible. For gambits the most critical continuations are generally to take the material and try to keep it, which means your best bets are probably to either decline the gambit or to return the material to reach a tenable endgame. For the gambit you've listed, that means do not play 3...dxc3; go instead for something like 3...d5 or 3...Nc6.

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


# Question
Title: Opening positions where declining a gambit is a blunder
Are there any gambit lines in which declining the gambit is a blunder or at least can be considered a misplay?

# Answer
> 15 votes
Sure, for example the Halloween Gambit. This is not a sound gambit at top levels of play, but if White plays it, Black must accept. The alternatives are even worse.

```
[FEN ""]
1. e4 e5 2. Nf3 Nc6 3. Nc3 Nf6 4. Nxe5 Nxe5 (4... Nxe4 5. Qh5 g6?? 6. Nxc6 wins) 5. d4 (5...Nc6 6. d5 Ne5 7. f4 Ng6 8. e5 Ng8) (5...Ng6 6. e5 Ng8 7. Bc4)

```

Black's best move is 4...Nxe5. Every other move except 4...Nxe4 gives away a pawn for nothing, and 4...Nxe4 allows White a dangerous initiative after 5. Qh5.

# Answer
> 11 votes
Some gambits whose best response is to accept.

1 e4 c5 **2 d4 cxd4** 4 c3: Sicilian Defence, Smith-Morra Gambit

1 d4 Nf6 2 c4 **e5 3 dxe5** Ng4 4 Bf4 Nc6 5 Nf3 Bb4+ 6 Nbd2 Qe7: Budapest Gambit

1 e4 e5 2 Nf3 Nc6 3 Bb5 g6? **4 d4 exd4** 5 Bg5: Ruy Lopez, Fianchetto Variation

1 e4 e5 2 Nf3 Nc6 3 Bc4 Nf6 **4 d4 exd4** 5 0-0: Italian Opening, Two Knights Defence

Does it count as a gambit if the gambited unit is captured but not immediately after it is moved? (You could argue that the gambiting player gambits a unit by not defending it.) If this counts:

1 e4 **e5** 2 Nf3 Nf6 3 **Nxe5** d6 4 Nf3 Nxe4 5 d4 : Petrov Defence

**1 e4 e5** 2 Nc3 Nf6 3 f4 d5 **4 fxe5 Nxe4** 5 Nf3: Vienna Gambit Declined

1 d4 Nf6 **2 c4** e6 3 g3 d5 4 Bg2 **dxc4** 5 Nf3 Be7 6 0-0 0-0: Catalan Opening

I don't count captures where the capturer is immediately recaptured, because these are termed exchanges rather than gambits. But the question "should I start this exchange?" is just as valid as "should I accept this gambit?".

You might count the Danish Gambit

1 e4 e5 2 d4 exd4 3 c3

on the basis that White *gambited* wPd4. However, Black might well have expected an *exchange* on d4; the mainline is the Centre Gambit 3 Qxd4.

---
Tags: opening, gambits, blunder
---


# Question
Title: Rating system (glicko, elo, etc): is 'predict the outcome of games' the same thing as 'reduce the number of upsets'?
From Lichess page 'Chess rating systems':

Question:

> Which rating system is best?

Answer:

> The purpose of rating systems is to predict the outcome of games. Therefore, they can be objectively better or worse, according to their ability to make such predictions. Glicko 1 makes better predictions than Elo, and Glicko 2 makes better predictions than Glicko 1

My question: **Is 'predict the outcome of games' the same thing as 'reduce the number of upsets' ?**

Upset here is simply lower rating defeating (or drawing against?) higher rating. Thus, assuming all ratings are integer valued and no 2 players of equal rating play against each other, what I understand is that

'1800 is more likely (or at least as likely) to beat a 1700 if the ratings are glicko 2 as compared to glicko 1'

if and only if

'Glicko 2 makes better predictions than Glicko 1'

**Is there anything I misunderstood?**

# Answer
> 1 votes
Basically correct. (Note that these rating systems don't natively deal with draws, only with binary wins/losses. Draws are incorporated by summarizing results as point-score = wins + 0.5 * draws.)

---
Tags: rating, statistics, elo, mathematics, glicko
---


# Question
Title: History of convention for king & queen placement
As stated in this question, the convention that the player with the lighter-coloured pieces makes the first move was not established until fairly late in the 19th century.

Before then, what convention (if any) was there as to the placement of the kings and queens? For example, had the convention been established already, that if a player moved first, their king starts to the right of their queen?

Wikipedia is silent on this.

# Answer
> 5 votes
According to this translated version of *Libro de los Juegos* ("Book of Games"), page 7:

> And of the other pieces which are greater one resembles the king, who is the lord of the army and he should be in one of the two middle squares.
>
> And next to him in the other middle square, is another piece which resembles the fers (alfferez) who carries the standard of the king's colours. And there are some men who do not know the name and call him "fersa" (alfferza). \[...\]

It's worth noting that the queen was originally called *fers*.

---
Tags: rules, history, queens, kings
---


# Question
Title: How long could a player last with all their possible moves written out in advance?
In this scenario:

Black plays normally (and optimally).

White has prepared a long list of possible moves for each turn before the game starts, then movement is automatic. Each turn, each move for that turn is checked in order, and if it is legal, it is played (and the rest of the possible moves for that turn are discarded).

(White needs to unambiguously specify the piece type they are moving, and whether it is a capture or not, and what they are promoting to, if anything. They don't need to indicate whether they are checking.)

For instance, let's say white prepares:

1. e4
2. exd5 e5 Nc3

If black plays 1..d5, white captures. If black plays 1..e5, white plays Nc3. Otherwise, white plays e5.

(If white ever has no legal, unambiguous move prepared, they lose.)

Question: what is the longest number of moves white could avoid losing, in this scenario? (I'm assuming Black can force a win)

I imagine it may be very difficult to compute exactly, but I'm interested in estimates etc.

Assuming that black cannot see white's move list ahead of time, are there any interesting strategies black should employ?

Assuming that black *can* see white's move list ahead of time, how does that change the main answer?

# Answer
TLDR: The best we can claim is that the number of moves for black to force a win is bounded by the number of moves for black to force a win in a regular game of chess, a number that we don't know.

---

Consider the following position:

```
[FEN "8/1k5R/R7/1K6/8/8/8/8 - - - 0 1"]

```

We can then specify a winning solution for white like so.

2. rg6
3. rg8#

However, we can use this example to show that in order for white to have a winning strategy in this game, they must have a winning strategy for chess itself. To do so, let's consider how the solution above was generated.

We first consider all the possible moves for black. In this scenario, those are 1 ... kb8 and 1 ... kc8.

Since the problem doesn't provide us a way to conditionally specify a move other than determining whether the move is valid, we must specify a strategy that is winning regardless of what black plays in a situation.

Regardless of which move black chooses, 2 rg6 will be a valid move, thus we progress to a scenario where black's king is son the 8th rank and white has two rooks on the 7th. Neither can be reached by the king before being checkmated. On this turn, black can either play, 2 ... ka8 or 2 ... kc8 if they played 1 ... kb8; or they can play 2 ... kb8 or 2 ... kd8 if they played 1 ... kc8. We can picture this move set as a decision tree (this will be helpful when we go to generalize this situation). Regardless of what black plays on either of their turns, 3 rg8# is innevitable.

How did white select these moves? That's the natural question to ask, and we can build on our concept of a decision tree to do it. After each move by black we can envision a similar decision being made by white. Enumerating all of whites possible moves would be much more verbose, but certainly possible \[1\]. In each of these positions, we would then evaluate the position as white to determine if it led to a further winning strategy for white. We make a move if, regardless of what black does, there is a forced mate for white. This is the well known Minimax algorithm.

---

Call the position above *P(n)* where *n* is the move number of the game ending in this position. *P(n+1)* would be the position following this, as we've described above, and *P(n+2)* is checkmate.

Now let's talk about the answer to the question itself, *P(0)*, also known as the start of a game of chess. There are 12 possible moves black could play on move 1. All of them are valid regardless of what move white made, and white must consider all of them at once to make their next move.

If for instance the game began 1 e4 d5, the move set specified by white on turn two could include 2 exd5 d4. We could also read this as, if black plays the Scandinavian defense, white plays the Scandinavian closed. Otherwise, white plays d4.

On each turn, white must enumerate all possible moves after all possible moves by black from the current position *P(t)* for some turn *t* otherwise they will lose. A sensible way to order these could be defined as the minimax sorting by number of moves until forced checkmate, and this is a more restricted problem to providing a minimax solution to chess itself. **Therefore, the best we can claim is that the number of moves for black to force a win is bounded by the number of moves for black to force a win in a regular game of chess, a number that we don't know.**

To answer the other two questions, since white must plan for all possible moves from black in order to avoid losing, there cannot be any unique strategies for black since that strategy would, by the definition of how white selects a strategy, be considered by white. Assuming black can see the move list ahead of time, they would simply see the strategies white attempts to employ for whatever they play (such as seeing their decision to play the closed Scandinavian presented above). If black is making optimal moves anyways, I think this is unlikely to affect their performance, however if the white player is playing at their skill level, they may be able to find a weakness in their play just as they would in a standard game of chess.

\[1\]: The rook on h7 would be able to move to any square on the h-file or 7th rank, the rook on a6 could move to any square on the a-file or the 6th rank, and the king could move to any of the surrounding squares except a6.
> 4 votes

---
Tags: puzzles
---


title: Are pawns pieces?

text:
# Question
Title: Are pawns pieces?
I thought I heard somewhere that pawns are not pieces but just called pawns. Then, I heard from some other places that they are. I think they are but what is the exact definition of a pawn?

# Answer
> 30 votes
I think a "piece" in the chess context is typically shorthand for the more specific terms of a "minor piece" (Knights and bishops) or a "major piece" (Rooks and Queens).

However, one could reasonably point out that the category of "chess pieces" in the typical board game sense should surely include pawns, and I'd have to agree.

So while the term is very commonly used and understood to refer to major/minor pieces, I think fundamentally it's at least a little ambiguous and when communicating especially with non-chess players it's probably best to simply be more specific, at least the first time the term is used.

# Answer
> 10 votes
No, the word "piece" does not include pawns. We can see this in some common phrases. A "minor piece" is a bishop or a knight – pawns are even more minor but don't count as minor pieces.

The word "piece" is also used in phrases where it implies "bishop or knight" because if the piece in question had been a queen, rook, or pawn, this would have been specified. For example, when we say that a player is up or down a piece.

One usage that might confuse the issue is that the physical objects we move on the board are called "pieces", and this refers to the pawns as well as to the pieces. We also see this usage when we say that in one game one player "has the White pieces".

Wikipedia lists these usages.

# Answer
> 9 votes
**Yes**. According to the FIDE Laws of Chess (emphasis mine):

> 2.2. At the beginning of the game White has **16** light-coloured pieces (the 'white' pieces); Black has **16** dark-coloured pieces (the ‘black’ pieces).
>
> These pieces are as follows:
>
> * \[...\]
> * **Eight white pawns** usually indicated by the symbol
> * \[...\]
> * **Eight black pawns** usually indicated by the symbol

There are also other articles implying that pawns are pieces:

> 3.7.5.3 This exchange of a pawn for **another piece** is called promotion, and the effect of the new piece is immediate.

However, it's worth noting that a pawn isn't considered a piece in terms of the *Algebraic System*:

> C.1 In this description, ‘piece’ means a piece other than a pawn.

# Answer
> 5 votes
I think it's just convention (see appendix). There are some sayings like

> 'In endgames, when you're winning, trade down. But trade pieces, not pawns.'

If you consider pawns as pieces, then this becomes

> 'In endgames, when you're winning, trade down. But trade non-pawns instead of pawns.'

Seems pretty weird.

There are also some definitions of the start of endgames like

> (for lichess) Endgame starts when there are 6 pieces except kings.

If you consider pawns as pieces, then this becomes.

> (for lichess) Endgame starts when there are 6 pieces except kings and pawns.

(I cannot think of examples that do not involve endgames.)

---

Appendix:

It's like in financial accounting when 'accounts receivable' (basically IOU's) are considered 'tangible' by 'accounting fiction' even when by our everyday understanding of the word 'tangible' they are 'intangible'.

or like the definitions of open and closed in topology: under these definitions, a set can be both 'open' and 'closed' (look up 'clopen'), but in our everyday understanding of these terms a door cannot be both open and closed.

# Answer
> 2 votes
In discussions of strategy, "piece" usually does not include pawns. In some contexts it may just mean knights and bishops. "Black is up a piece and a pawn".

In all other contexts (rules, board setup, physical set design, computer engines, etc) "piece" usually does include pawns.

There are some ambiguous contexts where it's not clear.

For instance, "there were 6 pieces left on the board". If this was a line in a book that is not about chess strategy, I'd assume it includes pawns. If this was a line in a report on a chess match, I'd assume it doesn't (but I wouldn't be certain whether it included the kings).

---
Tags: pawns, terminology, pieces
---


# Question
Title: Do I have the right to resign on my first move or within 10 moves?
In chess, does a player have the right to resign within the first ten moves of the game? More specifically, I am curious if I can resign immediately on my first move. Additionally, do I have my right to resign when it's my opponent's turn, or must I resign only when it's my turn? More specifically, I am not talking of casual street chess; I am referring to FIDE tournaments, e.g. official play rules.

# Answer
FIDE Handbook's Laws of Chess (Section 5.1.2) states

> The game is won by the player whose opponent declares he resigns. This immediately ends the game. (source)

Players may resign at any time, regardless of whose move it is.

As an example of an early resignation (move 6), consider Zapata-Anand (Biel, 1988).

```
[FEN ""]
[Event "Biel-B"]
[Site "Biel SUI"]
[Date "1988.07.??"]
[EventDate "?"]
[Round "9"]
[Result "1-0"]
[White "Alonso Zapata"]
[Black "Viswanathan Anand"]
[ECO "C42"]

1.e4 e5 2.Nf3 Nf6 3.Nxe5 d6 4.Nf3 Nxe4 5.Nc3 Bf5?? {This blunder loses a minor piece.} 6.Qe2 1-0

```

A more recent example of an early resignation (move 10) is Dominguez Perez-Moradiabadi (St. Louis, 2022) in the US Championship.

```
[FEN ""]
[Event "U.S. Championship"]
[Site "Saint Louis USA"]
[Date "2022.10.12"]
[EventDate "2022.10.04"]
[Round "7"]
[Result "1-0"]
[White "Dominguez Perez,L"]
[Black "E Moradiabadi"]
[ECO "C42"]
[WhiteElo "2747"]
[BlackElo "2534"]
[PlyCount "20"]

1. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 Nxe4 5. d4 d5 6. Bd3 Be7 7. O-O Bf5
8. c4 O-O 9. cxd5 Qxd5 10. Bxe4 1-0

```
> 22 votes

# Answer
> I am curious if I can resign immediately on my first move

You may but the game will not be rated. Both players must make at least one move for the game to be FIDE rated. If the arbiter thought your action had bad intentions or was in some way malicious they could punish you under article 11.1

> 11.1 The players shall take no action that will bring the game of chess into disrepute.

I have never seen this done but about 50 years ago Tony Miles and Stewart Reuben got into trouble for agreeing a draw with no moves made.

> do I have my right to resign when it's my opponent's turn, or must I resign only when it's my turn?

You can resign whenever you want. I have done this in a FIDE rated game when I made a move which was so embarrassingly bad that I didn't want my opponent to reply. That would have made me feel even more foolish. I made the move, pressed the clock, went to write the move down and then realised what I had done and knocked my king down, stopped the clock and held out my hand.
> 22 votes

---
Tags: rules, tournament, fide, resigning
---


title: Literarily weak knights

text:
# Question
Title: Literarily weak knights
When I was young, the knight was sometimes lousy and knights took the cake. It happened more than once that I hammered a knight sacrifice into the rows of my opponent during blitz...the effect being greatly diluted by the fact I only hammered the top half, the bottom still standing on the departing square.

Question: I assume "material malfunction" is practically absent in modern tournament chess (or can you tell anecdotes?) and simply stopping the clock and calling the arbiter does it?

# Answer
> 7 votes
> simply stopping the clock and calling the arbiter does it?

No! If *this* arbiter sees you deliberately using excess force which leads to (further) damage to equipment then a first offence will get you a stern warning and the second ejection from the tournament and a ban.

According to the FIDE Laws of Chess:

> 11.5 It is forbidden to distract or annoy the opponent in any manner whatsoever.

It is even more important not to disturb or annoy the organizer or arbiter.

One of the great benefits of digital clocks and increments was that players lost any excuse (if ever there was one) for hitting clocks in time trouble.

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Tags: rules, history, fide, pieces
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# Question
Title: Why does Stockfish evaluate Nd4 as an inaccuracy in this particular game?
Here is the position:

```
[FEN ""]
1. e4 d5 2. exd5 Qxd5 3. Nc3 Qe6 4. Be2 Nf6 5. Nf3 Ne4 6. Nd4 Qd5 7. nxd5

```

I have two knights here. One knight is being attacked by the knight at e4. My other knight is at c3. I moved my knight to d4 to attack his queen. The reason I did that is because he has to move either his queen or knight. If he move his knight, I take his queen; if he moves his queen, I take his knight. Surprisingly enough, he moved his queen to d5. So, I took his queen. Also, Stockfish wants me to castle. This unorthodox move puts my knight into a very dangerous spot. If he were to take my knight at c3, I would have to take his knight either with the pawn at b2 or the pawn at d2. His queen could also become a threat to my king if he pair his queen with a bishop.

I do not see why castling can be beneficial in this position. So, what is the advantages of castling here? And, why is 6. Nd4 an inaccuracy?

The game is also here: https://lichess.org/FF4CHOWP/white#12

# Answer
> 3 votes
The reason is because in the situation if Qb6 is played then you could lose the knight. But if you move the knight you will lose the game because Qf2# is checkmate. white moves Nb5 then black will play a6 receiving a knight or the game.

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Tags: analysis, strategy
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# Question
Title: Is playing without a clock, with the arbiter adding the clock when the game goes too long, within FIDE rules?
There was a time I joined a tournament where we didn't play with a clock initially. But, if the games went longer than 30 minutes, the arbiter added a 10-minutes clock to both sides.

Is this allowed by FIDE rules?

# Answer
> is this allowed by FIDE rules?

The FIDE Laws of Chess are divided into two sections:

> BASIC RULES OF PLAY

which has 5 articles:

> Article 1: The nature and objectives of the game of chess
> Article 2: The initial position of the pieces on the chessboard
> Article 3: The moves of the pieces
> Article 4: The act of moving the pieces
> Article 5: The completion of the game

No mention of chess clocks so you can play a perfectly legal (according to FIDE) game of chess without chess clocks.

The second section

> COMPETITION RULES

covers the rules for competions and has 7 sections:

> Article 6: The chessclock
> Article 7: Irregularities
> Article 8: The recording of the moves
> Article 9: The drawn game
> Article 10: Points
> Article 11: The conduct of the players
> Article 12: The role of the Arbiter (see Preface)

So, only if chess is played in a formal competition do chess clocks play a part and so far in the rules there is no mention of time controls. The first mention of time controls is in Appendix A and then Appendix B

> 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.

> 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.

What you have described conflicts with these appendices which means that this competition could not be FIDE rated for either rapid or blitz. Most federations have similar rules for nationally rated competitions so such a competition, in those circumstances, could not be nationally rated.

The FIDE Rating Regulations effective from 1 January 2022 cover the regulations for FIDE rating standard time control chess and say this:

> 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.
>
> 1.2 Where a certain number of moves is specified in the first time control, it shall be at least 30 moves.

So, what you describe is allowed within FIDE rules for chess but the games may not be FIDE rated.
> 6 votes

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Tags: rules, fide, chess-clocks
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