# Question
Title: Quick method for generating FEN strings from PGN using Python Chess
Is there a **fast** way to generate FEN strings for every move in a PGN?

I'm generating an opening book using the Lichess elite database and Python Chess, but Python Chess is taking a surprisingly long time to analyze games and generate FEN strings for each move. Like, 1/1000th the speed I expected.

This is how I've done it - it works, but again, slow. `board = game.board()` is the primary slowdown - but I don't see a way to get FENs directly from the game object.

```
# PARSE PGNS and create an opening book using a giant dictionary

import chess
import chess.pgn
import io
import datetime

#START WITH SOME DUMMY DATA FOR DEBUGGING

games = '''[Event "Rated Rapid game"]
[LichessURL "https://lichess.org/YcFqJqyM"]
[Date "2020.06.01"]
[Round "-"]
[White "Poecraft94"]
[Black "Germanvince"]
[Result "1-0"]
[WhiteElo "2323"]
[BlackElo "2415"]
[ECO "B50"]
[Opening "Sicilian Defense"]
[TimeControl "600+0"]
[UTCDate "2020.06.01"]
[UTCTime "00:00:01"]
[Termination "Normal"]
[WhiteRatingDiff "+9"]
[BlackRatingDiff "-8"]

1. e4 c5 2. Nf3 d6 3. Nc3 Nf6 4. g3 g6 5. Bg2 Bg7 6. O-O O-O 7. d4 cxd4 8.
Nxd4 a6 9. Re1 Nbd7 10. Bg5 Rb8 11. Nd5 e6 12. Nxf6+ Bxf6 13. Bxf6 Nxf6 14.
Qd2 Qc7 15. Rad1 Kg7 16. Nf3 Rd8 17. e5 Ne8 18. Re3 b5 19. Rd3 d5 20. Rc3
Qe7 21. Nd4 Bb7 22. Rf3 Rbc8 23. g4 h6 24. Rh3 g5 25. f4 gxf4 26. Rh5 Nc7
27. Qxf4 Rh8 28. Rf1 Rcg8 29. Rf5 Rf8 30. g5 h5 31. Bh3 b4 32. b3 Nb5 33.
Rf6 Nxd4 34. Qxd4 Bc6 35. R1f2 Bd7 36. Qa7 Rh7 37. g6 1-0

[Event "Rated Blitz game"]
[LichessURL "https://lichess.org/AY9kSWFt"]
[Date "2020.06.01"]
[Round "-"]
[White "sandstorm00"]
[Black "yendorzerep"]
[Result "1/2-1/2"]
[WhiteTitle "NM"]
[BlackTitle "IM"]
[WhiteElo "2497"]
[BlackElo "2426"]
[ECO "B06"]
[Opening "Modern Defense: Standard Line"]
[TimeControl "180+0"]
[UTCDate "2020.06.01"]
[UTCTime "00:00:19"]
[Termination "Normal"]
[WhiteRatingDiff "-1"]
[BlackRatingDiff "+1"]

1. e4 g6 2. d4 Bg7 3. Nc3 c6 4. Be3 d5 5. e5 f6 6. exf6 Nxf6 7. Bd3 O-O 8.
h3 Nbd7 9. Nf3 Qc7 10. Qd2 e5 11. dxe5 Nxe5 12. Nxe5 Qxe5 13. O-O-O Bf5 14.
Bxf5 Qxf5 15. g4 Qf3 16. Rhg1 Ne4 17. Nxe4 Qxe4 18. h4 a5 19. h5 a4 20. a3
Rae8 21. Rde1 Qe5 22. c3 Qd6 23. f4 Re4 24. hxg6 hxg6 25. f5 Rfe8 26. Bf2
Rxe1+ 27. Bxe1 d4 28. Bf2 Re4 29. fxg6 Qxg6 30. Bxd4 Bxd4 31. cxd4 Rxg4 32.
Rxg4 Qxg4 33. Qe3 Kf7 34. Kd2 Qe6 35. Qf4+ Ke7 36. Qc7+ Qd7 37. Qxd7+ Kxd7
38. Kc3 Kd6 39. Kb4 b5 40. b3 axb3 41. Kxb3 c5 42. dxc5+ Kxc5 43. Kc3 Kc6
44. Kb4 Kb6 45. a4 bxa4 46. Kxa4 1/2-1/2'''

# If you have the Lichess elite database, yoou can parse the entire thing by uncommenting here

#with open('/lichess_elite_2020-06.pgn') as f:
#    games = f.read()

games = games.replace("\n\n[", "||||[")
pgns = games.split("||||")

import time

fens = {}
start = datetime.datetime.utcnow()

for i, pgn in enumerate(pgns):
    game = chess.pgn.read_game(io.StringIO(pgn)) #parse each pgn string
    if game.errors:
        continue

    parent_pos = None
    move_num = 0

    while game:
        move_num += 1
        if move_num > 40: #practically, we only need to first 20 moves for our book
            break

        game=game.next()

        if game:
            board = game.board()
            pos = board.fen(en_passant='fen') #grab fen string of current position
            move = game.san() #what was the last move made?

            if pos not in fens:
                fens[pos]={}

            if parent_pos:
                #in the previous position, the current move was made X times
                if pos in fens[parent_pos]:
                    fens[parent_pos][move] += 1
                else:
                    fens[parent_pos][move] = 1

        parent_pos=pos

print('Run time: ', (datetime.datetime.utcnow()-start).seconds)

```

This yields a data structure with FEN strings as keys, and the most common replies as values. E.g. after parsing the 2 games, e4 is followed by g6 once and c5 once.

<pre><code>{
    'rnbqkbnr/pppppppp/8/8/4P3/8/PPPP1PPP/RNBQKBNR b KQkq e3 0 1': {
        'c5': 1,
        'g6': 1}
...
}```
</code></pre>

# Answer
> 5 votes
If you are not tied to using PythonChess and simply want FEN encodings of each position, you might like to consider using my free, open-source pgn-extract program with its -Wepd option to output in EPD format. It is a compiled C program so likely to be significantly faster for this use case. For instance:

```
pgn-extract --quiet -Wepd games.pgn

```

Here are the first few lines of its output for one of the games quoted in the OP:

```
rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - c0 sandstorm00-yendorzerep Rated Blitz game 2020.06.01; c1 1/2-1/2;
rnbqkbnr/pppppppp/8/8/4P3/8/PPPP1PPP/RNBQKBNR b KQkq e3 c0 sandstorm00-yendorzerep Rated Blitz game 2020.06.01; c1 1/2-1/2;
rnbqkbnr/pppppp1p/6p1/8/4P3/8/PPPP1PPP/RNBQKBNR w KQkq - c0 sandstorm00-yendorzerep Rated Blitz game 2020.06.01; c1 1/2-1/2;

```

If you wish to suppress irrelevant en passant squares then there is also the --nofauxep option to do that.

# Answer
> 0 votes
As Kevin indicated, you're reevaluating your entire position after every move. A better way to code would be to use the `next` method. Below is a code snippet that should give you an idea:

```
import chess.pgn
pgn = open("anderssen_kieseritzky_1851.pgn")
mygame=chess.pgn.read_game(pgn)
while mygame.next():
    mygame=mygame.next()
    print(mygame.board().fen())

```

---
Tags: database, pgn, fen, python
---


# Question
Title: Can I use Lichess to store my over-the-board games?
I recently got back into playing long games over the board, and I'd like to have some kind of database of my played games. This database would need to include searchable metadata including game date and opponent name and ELO. I already use Lichess to analyse my games.

Does Lichess have this capability? If not, does any other popular open-source tool?

# Answer
SCID is a free chess database application (that may be used as a ChessBase "alternative") that you can use to save your games, allowing metadata searches.

You could continue to analyse your games on lichess (even though you could of course also do it in SCID directly) in a study, export the study as PGN and import it to SCID to have it as a searchable database.
> 5 votes

# Answer
Beside SCID, there's also a good application called chessis, where you can store your Over The Board games. You can also analyze your game. I hope that I was beneficial to you.
> 1 votes

---
Tags: database, lichess
---


# Question
Title: Do chess have deterministic win strategy like tic tac toe? I.e. would God always win knowing the whole tree of combinations?
Chess is a totally deterministic game.

Although we do not have computing power to pre-compute all the possible moves, all possible outcomes are determined.

So assuming God had unlimited computing power, would He always win or draw? (Like in tic tac toe game)

Would white have an advantage over black considering they do the first move? Or vice versa?

Are there ways to estimate it considering analogy with tic tac toe where first player could always shift the game path to the draw scenario, even if both players play perfectly.

# Answer
> 2 votes
> So assuming God had unlimited computing power, would He always win or draw?

Yes, with the usual caveat: that's a big if. Infinity is not part of usual computational discussions.

But yes, with true infinite computing power (i.e., well outside the scope of what reality can offer), any pure strategy, no-hidden-info, 2-player game can theoretically be "solved".

And, if solved, it is pretty much agreed that white has no deficit in chess that would lead to black being able to force a win for black. The best black can hope for is a draw. White should at least be able to force a draw (if not win).

# Answer
> -1 votes
> So assuming God had unlimited computing power, would He always win or draw?

No. The difference between chess and tic-tac-toe is that tic-tac-toe is completely determined and chess will never be determined (there are more possible moves than atoms in the universe). Hence we don't know (and can never know) what the result with best play is on both sides. The popular guess is that it is a draw with best play but English GM Jonathan Speelman joked many years ago that in his opinion the initial position is mutual zugzwang. Hence a forced win for black.

---
Tags: strategy, mathematics, advantage
---


# Question
Title: In which tournament did Karpov play his first move with white pieces and offer a draw?
It had to have happened in the 90s, but I can't remember either the tournament or Karpov's opponent (probably some Spanish tournament, like Linares or Dos Hermanas). Karpov was upset with the organization for some reason, and he complained by playing 1. e4 and offered a draw that was accepted by his rival. As Karpov would say: "What would he do? Play for a win?"

I've tried some simple Googling via "shortest karpov game" and similar stuff, but I've gotte nothing at all. I have no idea how to use databases for a search like this, but I suspect that-for obvious reasons-this game probably isn't in any of them.

# Answer
> 25 votes
Not sure if this is it but this is the shortest Karpov game I found in the database.
Anatoly Karpov vs Peter Leko, Groningen 1995 where Karpov played 1.d4 and that's it.

The first comment there says

> karpov and leko did this quick draw to protest the abnormally early start of the round (9am if my memory is correct)

---
Tags: history, tournament, famous-games, karpov
---


# Question
Title: Can not determine the result of this endgame
The endgame is shown in diagram, and I have also submitted the moves from the actual game.

I want to know if any side can win, or is it really a draw.

*Support your claims with illustrative lines, please. Thank you.*

```
[Title "Black to move"]
[StartFlipped "0"]
[fen "8/6p1/1pBnk1p1/pPp2pP1/P2P1P1P/2K5/8/8 b - - 0 1"]

1...c4 2.Bf3 Ke7 3.Be2 Ke6 4.Bxc4+ Nxc4+ 5.Kxc4 Kd6 6.d5 Ke7 7.Kd4 Kd6 8.Kc4 Ke7 9.Kd3 Kd7 10.Kd4 Kd6=

```

## EDIT:

I must publicly apologize to user *Ken Wei* for unaccepting his answer. This is never a polite thing to do, and I will understand if there will be hard feelings.

I thought that he checked the lines with the computer, but it doesn't seem so.

User *Matt* pointed out refutation of user *Ken Wei*'s answer. That is why I have unaccepted the answer, because I want to know the truth -\> can any side win or is it a draw.

Therefore I urge future posters to prove their claims **with concrete lines** so we can avoid unpleasant scenarios.

# Answer
> 2 votes
OK: 1... c4 2. Bf3 Ke7 3. Bd5 Kd7 4. Bg8 Ke7 5.Bh7(!!) seems to win.

5... Kf7 6.d5 N somewhere and the King penetrates.

```
[Title "Black to move"]
[StartFlipped "0"]
[fen "8/6p1/1pBnk1p1/pPp2pP1/P2P1P1P/2K5/8/8 b - - 0 1"]

1... c4 2. Bg2! (2.Bf3 Ne4+! 3.Kxc4 (3.Kc2 Kd5-+) 3...Nd2+ 4.Kd3 Nxf3-+) 2... Ke7 3. Bd5 Kd7 4. Bg8 Ke7 5.Bh7! Kf7 6.d5+-

```

# Answer
> 2 votes
The final position is a draw, and is a case of opposition/corresponding squares. Black simply waits along c7-d7-e7, and plays Kd6 whenever white plays Kd4. (Although for future reference, you may notice that white can gain the opposition by sacrificing his pawn with d6, and meeting Kxd6 with Kd4, but in this case it doesn't win as the b6 pawn covers the entry point on c5; it would work if all the queenside pawns were shifted one rank towards the white side.)

It is crucial to recognise this idea from black's perspective, because it means that once the pawn on c4 is taken and the pieces are exchanged, white cannot win, so you need not calculate specific lines once you realise this: in particular, playing 3.Bd5 or 3.d5 for white makes no difference.

Hence white cannot win after 1...c4. To be specific for black: play c4, leave the knight on d6 and wait with your king. You need not worry about losing in lines where white plays h5, because after gxh5 Bxh5, the f5 pawn is protected by the knight (so Bg6 is not a threat), and e5 can be covered by the king in the pawn ending (so g6 does not win for white either, and in fact might even lose, but that argument is completely irrelevant).

Black certainly cannot win at any point: his knight is almost completely dominated by the white bishop.

# Answer
> 1 votes
In order to have a chance of winning, the white king has to be able to move to e5. By moving Kd6 if and only if white Kd4, black keeps the game a clear draw.

# Answer
> -1 votes
I went analyzing deep with Stockfish 14.1 NNUE depth 73 and it returns +2.50. In the followup, in the critical position, it leads to a Queen endgame winning for White.

---
Tags: analysis, endgame
---


# Question
Title: WCM titleholder without reaching 1800 elo
I came across this lady from Japan: https://ratings.fide.com/profile/7001800

She holds the WCM title, which according to the FIDE handbook requires that you have at one point in time reached 1800 elo rating.

However, her highest ever published rating is 1739 which doesn't even come close, so I doubt her live rating ever went above 1800.

The title was awarded in 2019. How is it possible for her to have this title?

Note: Nothing personal against this player, I'm just using her as an example to try and understand FIDE title regulations better.

# Answer
> 3 votes
For candidate masters titles (CM and WCM) there are two ways of getting the title:

1. Achieve a certain rating (2200 for CM, 2000 for WCM)
2. Achieve a certain position in an international event (World, intercontinental, continental, Olympiad, etc.). These include events for age categories as low as U7 (under 7), so you can be very weak and still qualify for the title. After a rule change in 2017, for this scenario you must also achieve a certain lower rating (2000 for CM, 1800 for WCM).

You do not need both.

Try this - go to the FIDE rating advanced search page and select

1. Title = WCandidate Master
2. Sort by = Rating, ascending

You will get this page which currently shows two WCMs with no rating and the next player, who received the WCM title in 2017, with a rating of 1015. Due to the 2017 rule change, these WCMs must have won their title in a tournament prior to July 1, 2017.

There are currently 796 WCMs and the advanced search spreads them out over 8 pages, so 100 players per page. The highest rated player on the first page is rated 1396.

# Answer
> 3 votes
The rules for titles changed on 1 July 2017. Previously, there was no minimum rating needed.

FIDE charges a fee for titles. It's possible that a direct title was earned before that date, but the fee was not paid until 2019.

---
Tags: fide, titles
---


title: Queen first, lose (or draw) later 4

text:
# Question
Title: Queen first, lose (or draw) later 4
Base: Queen first, lose (or draw) later

4. What is the most economical pawn endgame position where Black queens first but White wins, White pawns no higher than 6th rank on time of Black queening? (3+1 pawns suffice, so try to find or even beat that!)

# Answer
> 0 votes
Obviously optimal :

```
[FEN "8/5p2/8/8/8/1P6/2K5/k7 b - - 0 1"]

```

Black promotes first, with the wP still on the 6th rank, but they got mated after

> 1...c1Q 2.g7 Kh7 3.g8Q Kh6 4.Qg6#

---
Tags: pawn-endgame
---


title: Queen first, lose (or draw) later 3

text:
# Question
Title: Queen first, lose (or draw) later 3
Base: Queen first, lose (or draw) later

3. What is the most economical pawn endgame position where Black queens first but White draws, White pawns no higher than 4th rank on time of Black queening?

# Answer
*Edit*: Saving two pawns for an optimal solution

Black queens first but cannot win, no white pawn higher than the 4th rank, 1+1 pawns :

```
[FEN "8/8/8/6k1/8/7K/6pP/8 w - - 0 1"]

```

1...g1Q is stalemate and any other move draws as well

Funnily it is also possible with 0+2 pawns:

```
[FEN "8/8/8/6k1/8/6pK/6p1/8 w - - 0 1"]

```

1...g1Q/R stalemate

1...g1N/B 2.Kxg3=

1...Kf4 2.Kxg2=

---

*Previous answer*

An attempt with 2 pawns each:

```
[FEN "k7/8/8/7p/7P/7K/6pP/8 w - - 0 1"]

```

1...g1Q is an immediate stalemate. Other Black moves wouldn't win either:

1...Kb7 2.Kxg2=

1...g1R stalemate

1...g1B 2.Kg3 and the Ph5 will be captured

1...g1N 2.Kg2 Ne2 3.Kf3 Nd4 4.Kf4 and White is better !
> 1 votes

---
Tags: pawn-endgame
---


# Question
Title: Eyestrain - Anyone experiencing eyestrain when playing OTB?
As the title says. When playing blitz (3 to 5-minute games), I experience eyestrain after 10 or more games. After that, I start to blunder. I get tired too fast.

In our area, it seems to be only me who has this issue because my opponents can play a whole day without signs of exhaustion. Their plays don't change while my play changes after few blitz games. It is like starting from Elo 1850 then after few games it seems that I am playing like in Elo 1500-1600 while my opponent's strength and any other players' strengths in our area are the same the whole day.

By the way, I work online for at least 10 hours each day Monday to Friday. I play only on weekends. I have computer eyestrain too (a different case, not OTB chess eyestrain). But on weekends I still get eyestrain even when playing OTB only and not using a computer. I get enough sleep on Saturday, so I should not get eyestrain on Sunday when playing OTB, but it still happens.

How do I solve this issue?

# Answer
If you are genuinely getting tired "after 10 or more games" because of eyestrain and not just because you are getting old or you play in a stuffy, crowded room where there isn't enough oxygen then I would suggest you have a problem with the lighting.

In some playing areas I have problems when there is not enough light (maybe I'm in a darker corner of the room) or there is not enough contrast between the colours on the board and / or the colours of the pieces. This can give me eyestrain and make me feel tired but it would happen to me much quicker than after 10 games of blitz. If anything for me it would get a bit better after a while as my eyes and brain adjust a bit to the bad lighting conditions.

Note that some people have a problem the other way with over bright fluorescent lighting so I guess for tournament organizers it can be tricky to get it just right.

If I were you I would try and work out which lighting conditions give you the most problems and either sit somewhere where these problems are minimized and maybe if necessary ask the tournament organizer for help on this.
> 2 votes

# Answer
Possibly your eyestrain and performance drop are symptoms of a dropping blood pressure and physical tiredness. I used to have very lopsided scores in the two halves of rapid tournaments as well. Nowadays I try:

* Keeping the blood sugar level up.
* Washing my face with cold water.
* Some coffeine intake: Better a cold coke than a coffee.
> 1 votes

# Answer
It may be that you need glasses or adjust their strength if you already have some. Your eyes can compensate this to some degree, but it is really tiring and can easily lead to the symptoms you describe.
> 1 votes

# Answer
You should check the equipment.

What colour is your board? A mid-green-white board is **much** more gentle to the eyes than a black-and-white board. It's even more stressful for the eyes when the pieces are also Black and White and you have to strain your eyes to recognize black pieces on black squares. If you do not like green, you can also use other colours you like, as long as the contrast between the light and the dark squares is not too strong and you can easily and quickly recognize every piece on every square.

Chess.com uses this as their default. The "white" squares are not white and the dark squares are green. This is pretty optimal for the eyes, even though it may not be the prettiest, for (at least) the following reasons:

1. The contrast between light and dark squares is not too strong
2. No matter on what square a piece stands, you can always easily recognize the exact piece. White pieces have a slight contrast on the light squares and the black pieces have contrast on the dark squares.
3. There is still enough contrast between light and dark squares to tell them apart instantaneously.

Wooden boards are usually also very good for the same reasons, as the squares are coloured in two different shades of brown.

The following is an example of probably one of the **worst** possible setups:

It can be easily fixed by switching to a green board - then it would be a fantastic and beautiful set:

I don't assume a medical issue in your case, especially because you're only 25.
> 1 votes

---
Tags: otb-chess
---


# Question
Title: How strong should the evidence for cheating be, before you reveal it?
This is an extension of a question I asked previously here.

Somebody who can prove cheating beyond reasonable doubt might easily decide to tell the public about it all.

The main question is, what if you have evidence that is quite strong but doesn't amount to proof?

As in the previous question, I shall take a page from Ben Finegold, who proposes that all evidence (no matter how flimsy) should be discussed in public. He says that it is possible to regard an accusation of cheating as a compliment, in the sense that you may have played brilliantly and your opponent just got upset. Therefore, a mere accusation of cheating should not immediately lead to a defamation suit or suchlike.

To take Ben's proposal to its logical conclusion, if Magnus Carlsen had evidence which on the balance of probabilities indicated cheating, Ben would conclude that he should just give it to the public. He should say, "I don't have watertight proof, but I have evidence. Here is the evidence."

What would the consequences of this proposal be? Moreover, in today's cultural and legal environment, would the world's top grandmasters feel comfortable doing so?

# Answer
> 8 votes
> The main question is, what if you have evidence that is quite strong but doesn't amount to proof?

If you have any evidence whatsoever then the first thing you should do is tell the arbiter. The arbiter's job is then to judge that evidence and then see if there is any more evidence to support that claim. That includes not just what has happened in the past but also what happens in the future.

As an arbiter who has been in that position I can tell you that the most stupid thing you can do is broadcast to the world. That guarantees that the people tasked to find more supporting evidence will fail.

Obviously when such an accusation is made to the arbiter there are two possible outcomes:

1. Cheating is proven and the player faces sanctions usually including a ban
2. No cheating is proven. In this case the accused is innocent and should have no stigma attached to them.

Let's look briefly at the Niemann- Carlsen case.

1. Strong players have analysed the game and concluded that Carlsen played badly. It looks very much like an older insecure player trying to deflect from their blunders by a false accusation of cheating against an improving younger player.
2. IM Ken Regan has run Niemann's games through his cheat detection program and come to the same conclusion that Carlsen played badly and Niemann played well but nothing exceptional.

Regan is used regularly by them in serious cases. He has analysed Niemann's games and published the results. He has appeared in a number of interesting YouTube videos discussing these. Here is an example.

> Ben Finegold, who proposes that all evidence (no matter how flimsy) should be discussed in public. He says that it is possible to regard an accusation of cheating as a compliment

GM Ben Finegold is more of an entertainer than serious chess player these days. His current FIDE rating is 2400. He makes money by producing hundreds of YouTube videos and getting revenue on the number of clicks. Saying dumb but controversial things is a good way of driving that.

Carlsen, at a much higher level, is currently making a similar transition, this time from professional chess player to businessman. He has strong business links with Chess24.com and increasing revenue for them by saying outrageous things is good for him on a business level.

> What would the consequences of this proposal be?

Putting legal considerations to one side, the first and most important consequence would be that a possible cheater would be alerted and no more evidence would be gained. The only evidence would be historic which would likely already have been analysed. The second consequence would be to bring the game of chess itself into disrepute as a safe haven for scuttlebutt, innuendo and libel.

---
Tags: tournament, etiquette, cheating
---


# Question
Title: A rook up, can black end the checks and thereby win (LiChess.org puzzle 74754)?
A LiChess.org puzzle ends at this position with white to move. Apparently, black has a win here, but running through moves with LiChess's Stockfish, I can't seem to figure out how to end the checks.

```
[FEN "1K6/PPPq2PP/5P2/3p4/1p2Q3/7p/8/k2r4 w - - 0 1"]

```

**Question**: Can black end the checks and win?

Maybe there's a humanly understandable reason that the checks don't end. Or maybe the web version of Stockfish is not looking deep enough.

# Answer
> 3 votes
Looks like you are correct with your second assumption - the evaluation didn't (cannot) look deep enough.

It's a classic application of the horizon effect.

The white queen essentially has half of the chessboard at her disposal to give checks, while the black king has no shelter (the single rook is not enough (but moving it every now and then will reset the 3-fold-repetition countdown) and the black queen is cut off) but a lot of space to run around. The pawn on g5 will fall with check at some point and reset the 50-move countdown, too. The number of lines increases exponentially and since none of them actually changes anything significant about the position, Stockfish cannot efficiently prune any of them. Thus the search tree grows too large to process even for a modern engine on presumably good hardware.

---

PS: I've tried and removed the white pawns and the black pawn on g5 who look insignificant to the perpetual at first glance to reduce the number of chessmen to 7 - low enough to use Lichess' tablebase. And indeed, that position is won for black. However, this is meaningless as both sides will quickly play moves that are impossible in the puzzle position, e.g. the white queen will move to a1 and the black king will run towards e3.

# Answer
> 1 votes
At first I thought that the black king could hide on h5, but then I realized that I had made a fatal mistake for white in my analysis. With this mistake corrected, it is clear that black's king cannot hide on h5 without allowing a capture on e8 with check.

```
   [FEN "4r2k/8/p7/3Q2p1/4p3/2P5/PP2qPPP/6K1 w - - 0 1"]

  1.Qd4+ Kh7 2.Qd7 Kh6 3.Qc6+! Kg7 4.Qd7+! Kf6 5.Qd6+ (4.Qc7?? Kg8!)(3.Qd6+?? Kh5 {White is out of checks, and under the threat of mate on e1. It is, however, not game over just yet.} 4.h3 (4.g3 Qg4! {shuts down white's play completely.}) Qe1+ 5.Kh2 Qxf2 6.Qd7!? {Trying to set up a little trap.} Rh8 (6...Qf8?? 7.Qh7+ Qh6 8.g4+! {and now white is winning.}) 7.Qg7 (7.Qg4 Kg6 8. Qxe4+ Qf5 9.Qe6+ Qf6 10.Qe4+ Kh6! {White is out of checks, and black is winning.})( 7.g4+ Kg6! 8.Qe6+ Qf6 9.Qxe4+ Kh6 {and black's king is safe. Game over.}) Qf8)

```

The final position seems like a draw to me, since black cannot really escape the queen checks by any other means than by getting the king to c2. But this seems impossible, since that requires black's king to cross the d-file at some point, which white will be able to prevent.

Edit: I realized that my initial line was incorrect, and that white shouldn't just check along the d-file.

# Answer
> 1 votes
Black may be able to get his king trapped on a8:

```
[FEN "4r2k/8/p7/3Q2p1/4p3/2P5/PP2qPPP/6K1 w - - 0 1"]

1. Qd4+ Kh7 2. Qd7+ Kh6 3. Qc6+ Kg7 4. Qd7+ Kf6 5. Qd6+ Re6 6. Qd8+ (6.
Qf8+ Kg6 7. Qg8+ Kf5 8. Qh7+ Ke5 9. Qg7+ Rf6 10. Qxg5+ Ke6 11. Qg8+ Rf7
12. Qe8+ (12. Qg6+ Ke7 13. Qg5+ Kd6 14. Qd8+ Rd7 15. Qb6+ Ke7 16. Qc5+
Kf7 17. Qf5+ Ke8 18. Qe6+ (18. Qe5+ Re7 19. Qb8+ Kf7 20. Qf4+ Ke6 21.
Qh6+ Kd7 22. Qh3+ Re6 23. Qh7+ Kd6) 18... Kd8 19. Qb6+ Rc7 20. Qf6+ Kc8
21. Qf8+ Kb7 22. Qb4+ Ka8) 12... Kf6 13. Qh8+ (13. Qd8+ Kg7 14. Qg5+ Kh7
15. Qh4+ Kg6 16. Qg3+ Kf5 17. Qh3+ Qg4 18. Qxg4+ Kxg4) 13... Rg7 14.
Qh6+ Kf7 15. Qf4+ Kg8 16. Qb8+ Kh7) 6... Kg6 7. Qg8+ Kf5 8. Qf7+ (8.
Qh7+ Ke5 9. Qg7+) 8... Rf6 9. Qd7+ (9. Qh7+ Ke6 10. Qg8+ Rf7) 9... Kg6
10. Qe8+ Rf7 11. Qg8+ Kf6 12. Qd8+ Ke6 13. Qe8+ Kd6 14. Qd8+ Rd7 15.
Qb8+ Ke7 16. Qe5+ Kf8 17. Qc5+ Kf7 18. Qf5+ Ke8 19. Qe6+ (19. Qe5+ Re7
20. Qh8+ (20. Qb8+ Kf7 21. Qb3+ Kg7) 20... Kd7 21. Qd4+ Ke6 22. Qb6+
Kf7) 19... Kd8 20. Qb6+ Rc7 21. Qf6+ Kc8 22. Qf8+ (22. Qe6+ Kb8) 22...
Kb7 23. Qb4+ Ka8

```

The general strategy may be something like: Get the king to the middle of the board so you can block checks by moving re8-e6-f6-f7-d7, then get the king to the back rank and go Rd7-c7, and run the king to a8 (keeping in mind that if ke8 rd7 Qd5 then re7 will run white out of checks soon; the pawn on g5 is not necessary for this).

Losing the pawn on g5 seems OK; not sure if we need to.

(In the above game, I made little attempt to make all the lines follow my strategy above, opting instead to show other positions where white can run out of checks. I know it is possible to deviate from the game above and instead follow the strategy more closely because I did it against Lichess level 8.)

# Answer
> 0 votes
My feeling is that since black has mate in 1 threat, he can leave the rook undefended and march the K to go behind white's a/b/c pawns and end the checks. How exactly to get there I'm not sure, but I think white can't always keep d3 defended while giving checks non-stop.

Edit: After trying half hour against my phone, I now agree with the comments and other answers that such a plan is not possible.

---
Tags: perpetual
---


title: Rock, paper, scissors of chess players

text:
# Question
Title: Rock, paper, scissors of chess players
Chess players are typically rated by a single number, their Elo rating, which suggests that their skills are totally ordered and thus transitive. But I am wondering if there have ever been three (well-known) chess players A, B, C such that, according to general opinion or some statistically significant calculation, A is more likely to win against B, B is more likely to win against C, and C is more likely to win against A.

# Answer
> 6 votes
Found it! "Canonical" answer from "Dynamic Decision Making in Chess", p.9. Author Boris Gelfand quotes Beliavsky: Tal, Korchnoi and Stein were blitzing "Loser stands up" style, and all the time Tal lost to Korchnoi, Korchnoi to Stein and Stein to Tal.

# Answer
> 3 votes
To draw statistical conclusions, you would need a large enough sample. You will definitely find **a lot** of examples of "rock-paper-scissors"-configurations (RPSC) of players if you dig the head-to-head data, but this will very likely be due to pure chance and other factors.

For example, Nepo had a positive score against Carlsen prior to their world championship match (and they had played a decent number of games up to that point). However, in this count, there were also games that both players played in their youth, before reaching their current strength and development.

Nepo, despite having a huge talent for the game, slacked off, while Carlsen studied chess intensely. It would have been easy to find an RPSC at that point. Only find an opponent to who Nepo lost at some point in his life and who also played Magnus (and probably lost). One such players is Mateusz Bartel. He won a quite spectacular game against Nepo in 2015. Bartel lost against Carlsen in the Bundesliga in 2008. There you have your RPSC with well-known players (there are much more and probably better examples - I just took the first fitting player in alphabetical sorting).

Is this statistically "significant"? No. And with more games played, Nepo does not have a positive score against the stronger (w.r.t. Elo) player Carlsen. This should happen to about every such configuration you find in the data: have more games played, and the stronger players will eventually win the majority of the games. This is what Elo measures.

Now you could ask: what about style, or "most-feared-opponents"? If you only look at the top level (2600+), you'll find that those players are generally strong, without major weaknesses, displaying a universal style. Besides, the concept of "style" usually gets oversimplified. GM Karsten Müller very recently published an interesting book about player types and explains, that positional/tactical isn't a good/sufficient classification.

There, he analyzes the playing styles of world champions and that most of them have a similar style, with very few exceptions. The most notable is Tal, but according to Müller, players with his style could not succeed in winning the world championship matches in today's times with defensive techniques being better developed and chess engine preparation. Therefore, you will most likely have to move to lesser-known players (probably IM level) or go back in time and compare historical players.

I would reject any such configuration between 2600+ players in today's time as a statistical fluke.

---
Tags: rating, famous-players
---


title: Queen first, lose (or draw) later

text:
# Question
Title: Queen first, lose (or draw) later
I will soon teach my chess kiddies the laws of pawn endings. The overarching strategem is of course "Queen a pawn, Queen it first, Queen and stop calculating". Look at the easy win (Stockfish says) against even a pawn armada worth almost two queens (illegal, of course):

```
[FEN "8/4P3/pppppppp/pppppppp/8/4k3/8/4K3 w - - 0 1"]

```

But chess wouldn't be chess without exceptions. It could happen that you must assign the outcome of a queen endgame if the opponent queens too. The opponent can escape into a stalemate. The opponent might even mate you, even if the enemy pawn doesn't queen in the next move or at all!

For no peculiar reason I'd like to split the question in a) game only a draw after queening first/game even lost and b) rank of most forward enemy pawn *on time of Blacks queening move*, making 2\*6 questions. By the (IMHO unpractical) SE rules I must now split. Fortunately, for some questions I already know the answer, and some "dominate" others, so less than 12 questions remain for you to find an economy record. *(EDIT: Far less - Evargalo completely mopped up the "draw" case.)* Positions should be legal! (Unless noted otherwise) Please give always the position before Black queens (and if Black makes another move, it doesn't change the result!).

1. What is the most economic pawn endgame (least number of pawns; tie: less white ones) where Black queens first and still loses, White pawn on 7th?

Split off:

# Answer
> 6 votes
```
[FEN "k7/8/1K6/1p6/3P4/8/8/8 w - - 0 1"]

```

Obvious economy record. Hauke Reddmann, INSELSCHACH 1982 (no exact anticipation exists, but tons "in spirit"), White wins by 1.Kc7! ... 4...b1Q 5.d8Q+ 6.Qd4+ 7.Qa4#, i.e. mate is still two moves away after White queens! (Of course you can easily have more positions where White queens with immediate mate.)

# Answer
> 0 votes
4th rank, 4+1 pawns:

```
[Title "White plays and wins"]
[FEN "8/8/8/8/kPP5/2P5/1P5p/K7 w - - 0 0"]

1. Ka2 h1=Q 2. b3#

```

(Also works with 3+2 pawns, removing wPb4 or wPc4 and adding bPa5 or bPb5 respectively. All of these are drawn with bPh2 moved to c2, when Black answers 1 Ka2 with c1=N+!)

# Answer
> 0 votes
According to the 6-man "tablebases" White wins this 3+1 position only by forgoing promotion of either advanced pawn and instead advancing the other pawn to join its comrades on the 6th rank:

```
[Title "White plays and wins"]
[FEN "8/6K1/5P1P/8/6P1/8/1k4p1/8 w - - 0 0"]

1. g5! g1=Q 2. g6! 1-0

```

White eventually does promote at least one pawn and mates by move 32 with best play.

---
Tags: pawn-endgame
---


title: Queen first, lose (or draw) later 2

text:
# Question
Title: Queen first, lose (or draw) later 2
Base: Queen first, lose (or draw) later

2. What is the most economic position in a pawn endgame where Black queens first, but only draws, White pawn(s) not higher than rank 5 on time of Black queening? (This subsumes ranks 6 and 7)

# Answer
1+1, 2nd rank (from Black's side):

```
[Title "Black to play -- draw"]
[FEN "8/8/8/k7/8/K7/Pp6/8 b - - 0 1"]

1. b1=Q

```

(Even 0+1, if we assume that Black will Queen first and ask questions later)
> 1 votes

# Answer
An answer (maybe unique) is (seen from Black)

```
[FEN "8/4K3/8/5P2/8/2k5/3p4/8 b - - 0 1"]

```

where after 1...d1Q 2.f6 it's the usual draw of queen against bishop pawn. The point is that the black King stands very unfortunate: 2...Qe1+ 3.Kf8 and 3...Qb4+ isn't possible (thus f7 can't be impeded and the bK is out of the winning zone either).

This end position BTW is the heart of the following brilliant study:

```
[FEN "5K2/2p5/8/2k5/8/2P5/4P3/8 w - - 0 0"]

```

Mikhail Zinar, Shakhmaty v SSSR 1981, 1st special prize, 1.Kg7!!

What?? Why not 1.Ke7 or 1.Kf7? 1.Ke7? Kc4 is obvious: either Black gets both pawns or again Q vs bishop pawn arises, this time with black K already on b2. And after 1.Kf7? Kd5! we have mutual zugzwang, White's only try is 2.Kf6 Kc4 3.e4 Kxc3 and so on, where White queens even another move earlier, but now Black plays the K to d2 and we have the above position (with mirrored colors)! Thus 1.Kg7! Kd5 (Kc4 is easy, as above, again White queens another move earlier and Qg5+ wins in the end, unimpeded by a Kf6) 2.Kf7! and Black is in zugzwang. (Running to c3 is, as seen, one move short, running to Pe2 hopeless either.)
> 2 votes

# Answer
In case we want White to be winning and not just drawing, we need more pawns. This is probably not the most economical solution:

```
[FEN "8/5K1k/6p1/6PP/8/5p2/4p2/8 w - - 0 1"]

```

1...e1Q leads to an immediate mate: 2.hg6 Kh8 3.g7 Kh7 4.g8Q#

After 1...gh5 2.g6 Kh6 3.g7, Black has a choice:

* They still can promote first, but after 3...e1Q 4.g8Q they will get mated by 5.Qg7# or 5.Qg6#
* Or they can run away with 3...Kg5, but then they won't promote at all, e.g. 4.g8Q Kf4 6.Qg1+-
> 0 votes

---
Tags: pawn-endgame
---


title: Queen first, lose (or draw) later 6

text:
# Question
Title: Queen first, lose (or draw) later 6
Base: Queen first, lose (or draw) later

What is the most economical pawn endgame position where Black queens first but White wins, White pawns no higher than 4th rank on time of Black queening?

(FYI, Ke6 + 8 pawns on the 5th seem to win against Qd1+Ke1, but Ke5 + 8 on the 4th lose, trusting Stockfish)

(added so Noam can move his answer here, where it fits better. And I can post my rank 2 solution)

# Answer
> 3 votes
4th rank, 4+1 pawns:

```
[Title "White plays and wins"]
[FEN "8/8/8/8/kPP5/2P5/1P5p/K7 w - - 0 0"]

1. Ka2 h1=Q 2. b3#

```

(Also works with 3+2 pawns, removing wPb4 or wPc4 and adding bPa5 or bPb5 respectively. All of these are drawn with bPh2 moved to c2, when Black answers 1 Ka2 with c1=N+!)

# Answer
> 2 votes
Not a record but even all-on-base-rank pawns can mate:

```
[FEN "8/8/8/4ppp1/1K2kpp1/8/p2PPP2/8 w - - 0 1"]

```

1.Kc4! and queening is immediate mate, f3 only delays a move.

---
Tags: pawn-endgame
---


title: Queen first, lose (or draw) later 5

text:
# Question
Title: Queen first, lose (or draw) later 5
Base: Queen first, lose (or draw) later

What is the most economical pawn endgame position where Black queens first but White draws, White pawns on rank 3 or 4 on time of Black queening?

(added because well-known stalemate tricks are specific to rank 2, and rank 5 suffices as already shown in the Zinar study)

# Answer
> 1 votes
A super heavy construction, that certainly can be refined.

From Black's point of view:

```
[Title "Black to play -- lose"]
[FEN "8/8/6pp/6pk/5P1P/5PPK/p7/8 b - - 0 1"]

1...a1=Q 2.g4#

```

We can even have all wP on the third rank only:

White to play and win:

```
[Title "White to play -- win"]
[FEN "8/8/5pp1/3K1kp1/6p1/4PP1P/2p3P1/8 w - - 0 1"]

1.g3! b1Q 2.e4#

```

---
Tags: pawn-endgame
---


# Question
Title: A complex position with only eight pieces on the board ( computer chess )
```
[fen "8/6pk/N7/8/8/4rN1P/6PK/8 b - - 1 1"]

```

with Black to move or WHITE King on h2 Knights on a6 f3 pawns on g2 h3 BLACK King on h7 Rook on e3 pawn on g7 with BLACK to move. Is this eight pieces position a win for White or a draw ? The position is a variation of a Stockfish vs Slowchess game.

# Answer
> 3 votes
This is no definite answer and shouldn't be accepted, but too long for a comment. I entered the position into the LiChess engine, and the evaluation is steadily rising. This is typical for a position with slow plans. My own plan is based on standard endgame knowledge and I believe suffices for winning:

* First of all, get the horse a6 out of the botanics before it goes nowhere.
* At all cost avoid a pawn exchange, because then Black simply sacrifices the rook against the last pawn. You can't protect it from all sides (unless it is very far advanced).
* That said, gang up your two mares on the poor Pg7. If Black defends it with the rook, capture it anyway.
* Advance the pawns very carefully, especially the h pawn who wants no discussion with the Pg7.
* Side checks are easily blocked with the knights.
* At depth 50 Stockfish is at +2.0, and I'm too lazy to let it run, I have an appointment :-)

---
Tags: computer-chess
---


title: Utterly senseless move sequence

text:
# Question
Title: Utterly senseless move sequence
I noticed a game in my database with an utterly senseless move sequence , but approved from a database on the internet. I mean the game Viesturs Meijers - Roi Castineira Reinaldo , Pamplona 2008

Does someone have a source with a reasonable move-sequence ?

The game begins with

```
[fen ""]

1.c4 e5 2. b3 Nc6 3. Bb2 Nf6 4. e3 g6 5. Nf3 d6 6. d4 Bg7 7. dxe5 Ng4 8. Qd2 Nge5 9.Ne5 dxe5 10. Qd8 Nd8 11. Nc3 Ne6 12. Be2 Bf8 13. e4 Nc5 14. Rf1 Ne4 {from here on the moves make no sense)} 15. h4 h5

```

From 14...Ne4 the moves don't make sense.

# Answer
It looks like this game was recorded wrongly. Just because a game appears on a database it doesn't mean it's been "verified" by anyone.

If this game was stored automatically from a chess set with sensors, then there was probably some sort of malfunction going on. I doubt a game that looks this stupid could have been inserted manually.
> 1 votes

# Answer
I located the game in my personal reference database, Chessbases Mega Databases as well as 3 online databases.

In all databases the game presented as follows;

```
[Event "Pamplona-A 18th"]
[Site "Pamplona"]
[Date "2008.??."]
[Round "4"]
[White "Meijers, Viesturs"]
[Black "Reinaldo Castineira, Roi"]
[Result "0-1"]
[BlackElo "2516"]
[Classes "0"]
[ECO "A01"]
[TimeControl ""]
[WhiteElo "2514"]
[FEN ""]

1. c4 e5 2. b3 Nc6 3. Bb2 Nf6 4. e3 g6 5. Nf3 d6 6. d4 Bg7 7. dxe5 Ng4 8.Qd2= Ngxe5 9. Nxe5 dxe5 10. Qxd8+ Nxd8 11. Nc3 Ne6 12. Be2 Bf8 13. e4 Nc5 14. Rf1= Nxe4 15. h4 h5 16. Bg4 Nxc3 17. b4 b6 18. Bf3 c5 19. bxc5 bxc5 20. a4 0-1

```

I tend to agree that this isn't exactly the highest level of play. Just through a quick read through of the positions I count no less than 4 blunders , and yes they all kick off after *14. Ne4*
> 0 votes

---
Tags: master-games, reference-request
---


# Question
Title: Bogoljubow – Aljechin, Hastings 1922 - Zugzwang?
The German wiki has a whole page devoted only to this game, so I won't paste it here. Even as a very small kid with a rating of 1500 or so, I always wondered: is it really Zugzwang after 40...Qe2? Nonsense!, I thought. We can simply play h5 and then Rh4! puts a stop to the Ng4 idea. Doesn't this show that the position isn't Zugzwang?

Note that this doesn't claim White is not busted (he is), but merely that it isn't Zugzwang. Indeed, the best move of Black after h5 is given by the engine as Nd5, i.e. action. Let's be formal but lenient (if White is losing anyway, it can't be Zugzwang, strictly speaking game-theory-wise): we define White to be in Zugzwang if "pass" is the best centipawn move in the position. Rh4 makes Nd5 worse, since Ng4 is no longer possible, so this could be so. Obviously, Lichess Stockfish can't pass since that would be an illegal move, but I can enter the FEN with the "wrong" player to move, though. With a shallow analysis, I get -3.7 with WTM and -4.2 with BTM on standard depth 22. This is still not convincing: Black plays Kg8 and improves his king position for the big Qe2 exchange.

Can somebody (best with an engine allowing pass moves) analyze this deeper? I'd accept "Zugzwang" if, see above, White's centipawn value is least bad after a pass move.

# Answer
I'm not sure exactly how you'd be satisfied with an answer here, but yes this famous position is zugzwang. First of all the f1 knight cannot move without allowing Qxe3. The f2 knight cannot move without allowing Ng4! Rxe2 fxe2, winning. The rook cannot move without allowing Ne4! which cannot be taken due to Qg2#. And the king cannot move without allowing Qxf1. So really, the only moves left to consider are pawn moves.

```
[FEN "8/2p3pk/5n1p/5P2/3P1P1P/4Pp2/4qN1R/5NK1 w - - 1 41"]

1. e4 {is the only remaining try} (1. d5 Nxd5 {not played in the game - Kg8 was, just taunting Bogoljubov - but this is simplest}) (1. h5 Kh8! {Just to show the zugzwang, this move never accomplishes anything} 2. Rh4? Ne4! {which cannot be taken due to Qg2#} 3. Rh2 Nd2 4. Nxd2 Qxd2 {and black has broken through. Qxe3 or Qxf4 are unstoppable.}) Kh8 {not completely forced, but just to show that it's Zugzwang, we will consider this move.} 2. e5 (2. d5 Kh7! {once again showing the Zug} 3. h5 Kh8 4. e5 Nd5 {winning a pawn and the f4 pawn next}) Nd5 {and Nxf4 is unstoppable} 3. Ng4 Qe4 {does not change the nature of the position, white is losing all the pawns next.}

```

Once you exhaust all the possible pawn moves, it's easy to see that white has nothing to do.

Stockfish 14 says -5.1 at depth 28, with the top moves being all the three pawn moves we considered. If you pass the move, then the threat is Kg8 haha once again passing the move onto white with an evaluation of -5.1 as well.
> 2 votes

---
Tags: analysis, history
---


title: If Hans Niemann is cheating, how?

text:
# Question
Title: If Hans Niemann is cheating, how?
> Yesterday, Magnus Carlsen withdrew from the Sinquefield Cup 2022 after his loss to Hans Niemann in Round 3. Multiple tweets, streams, comments, and security checks later, the accusation of Niemann cheating is pretty obvious!
> Magnus Carlsen lost to the lowest rated player, Hans Niemann in Round 3....

(from https://worldchess.com/news/all/did-hans-niemann-actually-cheat-all-the-info-so-far/ )

If Hans Niemann is cheating, how?

# Answer
> 43 votes
The simple answer is that he is not cheating. Magnus just played badly. Had Magnus had proof he would have presented it at least to the arbiter. He didn't.

The chief arbiter, Chris Bird agrees with me. He released this statement.

> ### 2022 Sinquefield Cup
>
> ### Chief Arbiter's Statement
>
> **SAINT LOUIS, September 10, 2022** \- In response to the recent rumors circulating the chess world, I can confirm that we currently have no indication that any player has been playing unfairly in the 2022 Sinquefield Cup. This includes all rounds played to date.
>
> We have been running all the Grand Chess Tour events, including the Sinquefield Cup, and other major tournaments here in Saint Louis, for many years with the same strict anti-cheating measures that were in place for rounds 1-3, and we are not aware of any fair play violations during these past events. These measures included scanning of players with metal detectors prior to games and randomly after games, close observation of the players and fair play analysis by Professor Kenneth Regan using the FIDE Game Screening Tool.
>
> However, on behalf of all the players and the event, I consulted with Grand Chess Tour Chief Arbiter, IA David Sedgwick, and together we advocated that additional anti-cheating measures be enacted after round 3. These measures included the scanning of players with RF scanners and a 15-minute delay on the live broadcast. I am very thankful to the organizers in Saint Louis who immediately agreed to these requests, despite additional expenses, last-minute technical issues and the loss of a truly live broadcast.
>
> The arbiter team will continue to remain vigilant, and all of the anti-cheating measures that have been in place will continue to be so for the remainder of this event.
>
> IA Chris Bird
> Chief Arbiter, 2022 Sinquefield Cup
> Grand Chess Tour Deputy Chief Arbiter

Original image

# Answer
> 35 votes
I agree with Brian Towers, that the most likely scenario is that Hans didn't cheat (despite his weird behaviour in the interviews), as indicated by an engine check of the game.

**How would he have done it?**

OTB cheating sometimes happens. Usually, cheating individuals use hidden **mobile phones** on the toilet (e.g. like GM Igor Rausis). At top tournaments like the Sinquefield Cup, this isn't possible, as the players can't bring electronic devices (and also can't hide anything in the restrooms): they're scanned from head to toe (yes, shoes are also scanned).

The other way he could have cheated is by having an accomplice. This is also not very easy to pull off. GM Eric Hansen suggested that Niemann used remote-controlled **anal beads**. The absurdity of this idea tells you that even GMs aren't sure how he could have pulled this off (or GM Hansen just doesn't want to tell everyone how he does it ;) ). Naturally, Hansen evoked headlines around the world, especially in the yellow press. You can use your imagination to come up with a vibration protocol for transmitting moves (shouldn't be too hard). To make this cheat even harder, they introduced a delay after the game (but this was probably just for the sake of alleviating the affair of Magnus' retreat).

Let me add, that if we could easily answer this question, the security measures at the Cup would be insufficient. They would already have taken a countermeasure if any easy way to cheat existed. Tournament organizers and FIDE make sure in advance that any obvious cheating ideas are prevented. That includes help from electronic devices or third parties.

# Answer
> 21 votes
Things to keep in mind before reading this:
I do not like cheating, and I do not support it in any way.
Did he cheat? I do not know, I do not have any proof.
Why may he cheat? To beat Carlsen, because he was the strongest player in the tournament.
Let's imagine for this answer that he did cheat, to make things easier for us. How then?

Hauptideal mentioned "anal beads" and called it "absurd". Why? What do you really need in order to cheat as a GM?
Well, yes, there was that 15 minute delay, but after Carlsen's game, not in advance of it.
So we ignore that delay for now (but that is not a huge problem, just send the GM the moves for the 5 most probable reactions of the other player).

Let's think a bit:
We need something to calculate good moves for us. No problem, we can take any powerful enough PC and run an engine on it, no matter where it is at that moment.

Then we need to somehow tell the GM the move. Firstly we can use the public internet to bring the move close to him (like within a kilometer).

Then we need to get it right to him. Again, no problem, let's use LoRa (see Wikipedia article). This technology uses low power and covers a reasonable distance. The downside is that it is really slow. Really really slow. According to Wikipedia, it can transmit 292 bit/s up to 50 kbit/s. But that's more than enough: you can even transmit multiple possible moves within one second (each move needs two numbers between 1 and 64, that would be 2 * 6 bits per move). The device to do that can use WIFI or the normal cellphone network to connect to the internet, and would be as small as a pack of matches (including a battery). You can hide it literally anywhere within one kilometer (the range is theoretically higher, but let's say we limit it to a one kilometer range, to make sure it definitely works). So we can send the move to the GM.

But how can he receive it, without getting flagged by the scanners?
Firstly, he does not need to transmit anything: his receiver has only to be a receiver. So RF scanners are completely useless.
Secondly: The device must be quite small. Let's come back to the "anal beads". These are more or less small. You can easily fit a vibrator inside one - look at the ones used in smartphones: they are tiny, but quite powerful. Just need a little microcontroller, a tiny battery and an antenna. That's it.

If the metal detectors are not so sensitive, that is not a problem. Build the receiver out of plastic, and only the parts which really *need* to be metal out of metal, and you should not have a problem.
The receiver can have any size from a small ball up to the size and shape of a USB drive. If it is not bigger than this, you can even swallow it (there are tiny cameras with batteries you can swallow, which then transmit pictures of your digestive system to the doctor).
You just need to find a way to make it silent enough, but that should be doable as well...

Only way to find it is Xray.
Then use morse code or binary code or something.
Done. You just cheated.

How realistic is that?
I think it is definitely doable. Doable enough that I could build it without any problem. I could not use it, because I would lose during the opening of the game, and this would show its potential during long thinking periods (mid-game, end-game).

Ways to prevent that (you need all of them):
Not broadcasting the game at all.
Putting the players in a completely enclosed metal box.
No spectators.
The arbiters must be unbribable.
You have to prevent any RF transmissions (RF jammer, but you will get in trouble with police than).

EDIT: https://www.youtube.com/watch?v=5uDM3fPeNFM this is a build of such a device (not by me). I think, you can build it even smaller, if you want to.

# Answer
> 16 votes
I'm surprised so many people are discussing cheating during the game. Most likely that is not what happened at all.

What is most likely, I believe, is that Carlsen had a suspicion that his prep has been leaked by someone on his team. Not just now but in the recent past as well. So to prove to himself that suspicion he prepared with a very obscure line.

The fact that Niemann admitted that "by some miracle" he looked at that exact one game from many years ago where Carlsen played the same line before is as close as you can get to an admission of guilt, that he knew beforehand what Carlsen is going to play.

So if Niemann had access to Carlsen's prep, anyone could have had access to it. So it's logical to withdraw from the tournament.

# Answer
> 7 votes
Some people claim that he 'chewed gum' during the game (which can be observed), and that he swallowed it afterward (which I cannot verify). They also claim that the gum foil wrapper can shield from scanners (which I don't know). A vibrating device inside a fake wad of gum can easily convey enough information to help grandmasters. Even if these claims are debunked, there are many other possible ways to cheat, but I don't want to reveal it in case future cheaters get ideas. I mention the gum hypothesis because others have already suggested it.

# Answer
> 3 votes
Naroditsky said that he was once at an open tournament where a lower-rated player beat him at a game where one particular observer stood around, basically throughout the game. It was later revealed that that observer had a phone on him, which was against the rules.

This less technological way of cheating (making arrangements with other people who are on the site) is to my mind far more feasible than any of the wild suggestions concerning anal beads or electronic chewing gum.

# Answer
> -2 votes
Look carefully at the start of the Sinquefield game:

https://www.youtube.com/watch?v=MK8wuQxCRGo

It is the water-bottle. Niemann pretends to sip from his bottle before his first and his third move.

# Answer
> -3 votes
The chess clock can be used as an electronic receiver. A simple radio signal at a particular frequency could cause a very subtle interference pattern on the display that could be interpreted as a particular piece to move or some other hint.

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Tags: cheating
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# Question
Title: Is 10 minute time control too fast for me as a beginner?
Every day I usually play one or two 10+5 games for fun and to try to train my decision making. 10 minutes seems to be the recommended time control for a beginner. However, for a long time I've felt rushed with 10 minutes. I get in the habit of running out of time and making "lazy moves" since I feel like I have to play something. Is it better for me to play 30 minute or hour games, or even longer (one sitting) against a computer, to be able to "think through" and be more confident in my strategies? Or is that too long for beginners to focus and counterproductive to being decisive in actual games?

# Answer
> 5 votes
Maybe try increasing the time control in increments, until you find something that gives you meaningful games. 10+5 isn't really blitz, but it also doesn't feel like a typical rapid game. I'd recommend moving up to 15 10, 25 5, or 30 0, and see how you like those. 15 10 is fairly popular online, and the latter two are generally accepted as the main "rapid" time controls in OTB tourneys and such.

# Answer
> 4 votes
Everything depends on your goals.

The first that we need to accept is that bullet chess, every player has 60 seconds for the entire game, and classic chess are not the same game. Bullet and classic chess share all the rules but the time. In a similar way that the 100 meters, or 100-meter dash, is a sprint race, and the marathon is a long-distance foot race with a distance of 42.195 kilometers.

Nothing wrong with bullet, blitz, or correspondence chess, but it is important to understand that they are not classic chess (By the way, correspondence chess is in the other side of the spectrum, you can use a day or a week, and sometimes a month to make just a single move).

If your goal is to learn in depth classic chess, my advice is that you play just classic chess and correspondence chess. www.lichess.org calls classic chess when you play 30+0 ***OR MORE*** (30+0 means every player has 30 minutes for the entire game, a maximum of 60 minutes in total).

Most of the people argue that they play quick time controls because they do not have too much free time. However, the facts contradict that claim because they play an hour, sometimes two hours, and even more.

**The truth is that bullet and blitz are more popular because you can always blame the time if you make a mistake**. Also, if you play 10 bullet or blitz games, if almost impossible, from the mathematical perspective, that you lose all the games. Every time that we win a game, no matter which game is, our brain produces dopamine and we feel great. ***Maybe the greatest benefit of quick games, from the psychological perspective, is that if you make a mistake and lose for that reason, you can start a new game and you will forget the mistake because you are playing a new game. However, to improve in classical chess, we need to discover and remember our mistakes to try to avoid those mistakes in the future. That is why classic chess is so hard from the psychological perspective.*** Another bad habit that we get from speed chess is that we learn to play fast, and many times that produces big mistakes in classic chess. Nakamura would have played the world championship final against Nepomniachi but he played fast and lost against Ding Liren. Nakamura is the most famous speed chess player in our times, after Magnus Carlsen, of course. Some people, like Magnus Carlsen can play speed chess without a bad effect in classic chess, but we need to remember that Magnus is a genius. **My final advice is that you select one time control, no matter which time control is, and play ONLY in that time control.**

# Answer
> 2 votes
The answer is already in your question:

> I've felt rushed with 10 minutes. I get in the habit of running out of time and making "lazy moves" since I feel like I have to play something

This is completely normal as a beginner. I remember being anxious when my opponents opened with 1. Nf3 or 1. c4 for quite a while, until I got the (false) sense of security by having an opening repertoire.

**As soon as you have to rush and make lazy moves, this hurts your chess tremendously!** You'll get the bad habit of playing lazy moves instead of the principled approach, which would require calculation. You'll never become a strong player if you avoid the difficulties instead of trying to think and figure it out. For example, when the opponent attacks something, do you defend it as soon as you notice it? Or do you check whether you have something stronger and calculate whether the opponent can really afford to take the piece? The difficult parts are what make you grow your chess skills. In particular, **you learn more from the mistakes you make in your own games than anything else**. But you can *only* learn to correct your thinking if you have actually thought about the move and used enough time.

When playing faster time-controls, players rely mostly on two very important skills:

1. Intuition (you first must build that from **experience** in proper, long games! Not everything )
2. Fast and accurate calculation and pattern recognition (this also needs to be trained. No beginner starts as a perfect calculator or knows all the patterns).

This explains, why you should know how to play proper chess first, before playing blitz or 10 min rapid games if you really want to improve your chess!

> Or is that too long for beginners to focus and counterproductive to being decisive in actual games?

Not at all. On the contrary, it is a crucial skill to learn how to stay focused. It may be hard to focus at first, but you'll need it, *especially* for later in faster time controls. You'll be surprised how fast the time goes by if you truly dive deep into the position and think about your and your opponent's moves. I've had classical games, where hours passed like minutes.

Choose a time control where you do not feel rushed, even when you have already played quite a lot of moves, and always play with increment!

I would suggest playing 15+10, which you can play on chess.com or lichess.org. If you still feel that you had to rush some moves and couldn't think about everything enough in many games, play even longer time controls. Please note, that occasional time trouble is completely normal and part of the game. A major drawback of playing online only is that one is not used to playing "real" (i.e. classical) chess. If you do not have a club where you can play classical games, the best current alternative are the lichess 45+45 and lonewolf leagues.

You will also be much more proud of your classical games than on any random blitz or rapid game, where your opponent blundered something. The price of every move is higher, as you invested so much time in the game, but the reward will be even greater. Not only your happiness when winning a classical game, but what you learn from defeats as well.

# Answer
> 2 votes
**The longer time control, the better, if you want to improve.** Most streamers, GMs will advise you to play longer time control if you can to force you to make sound moves and not average moves that just put some time pressure on your opponent. As a 1800 in Lichess, I still struggle to apply strategy in 10+5 time. You can get a nice tactical level even if you play only blitz, but you'll never improve your strategy (long-term thinking, color complexes, unbalances, king safety, having a plan...) if you play blitz or faster. My favorite time is 10+5 (that's why I play on lichess) and I'm quite surprised that you picked it as a beginner. That's a great decision, but most people just do blitz for fun. (And that's fine if you don't care about improving). You need to find the most pleasant time control for you, so you'll be motivated to play chess. But **if you select longer than 10+5, that's great ! You'll get more in-depth knowledge about chess, and not just tactics.**

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Tags: learning, beginner, time-control
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# Question
Title: Is it possible to obtain the GM title directly without going through norm process in 2022?
I have seen people get direct GM titles especially in Zonal tournaments.
Here for an example achieved the GM title after winning the 2016 African Chess Championship.

Wikipedia page for the Grandmaster title states

> The Grandmaster title is also automatically conferred, without needing to fulfill the above criteria, when winning the Women's World Championship, the World Junior Championship, or the World Senior Championship, given that the player's peak FIDE rating is at least 2300. Current regulations can be found in the FIDE Handbook.

but this doesn't mention anything about Zonal events.

Is this still the case in 2022. Can someone achieve GM title directly in 2022 and if yes which events?

# Answer
> 2 votes
The current FIDE document defining how titles are earned is FIDE Title Regulations effective from 1 January 2022. This is what it says regarding "direct titles":

> **0.6 The Award of Titles**
>
> 0.6.1 Titles may be awarded for specific results in specific Championship events, or are awarded on achieving a rating as laid down in these regulations. Such titles are confirmed by the QC Chairman on advice from the FIDE Office. They are then awarded by FIDE.
>
> 0.6.2 For a direct title to be awarded immediately an applicant has to have achieved at some time a minimum rating as follows:
>
> GM 2300 WGM 2100
> IM 2200 WIM 2000
> FM 2100 WFM 1900
> CM 2000 WCM 1800
> If an applicant is rated lower the title is awarded conditionally and will be awarded finally on request by the respective federation as soon as the minimum rating is achieved. Any player with a conditional title may take a lower title when they reach the required rating for that lower title.

There are separate tables for direct titles. These notes apply:

> 1.2.4 erms used in Tables for Direct Titles:
>
> Gold = first after tiebreak
>
> 1st equal = best 3 players after tiebreak
>
> norm = 9 games
>
> Continental and Regional = Continental and a maximum 3 regional events per continent, and include Arab Youth.
>
> As above, each Continent is allowed to designate a maximum of 3 regional youth events for direct titles. The Continent must inform QC of any change in the composition of these regions before the beginning of each year.
>
> Sub-Continentals - include Zonals, Sub-Zonals and Arab adult.
>
> Zonals and Sub-Zonals are accepted for direct titles only if they establish qualifiers to the World Cup or World Championship.

These tables are specified in Table for Direct Titles effective from 1 July 2017

In summary these achievements entitle you to a direct title of GM:

> World Cup - Reaching last 16
> Women's World Cup - winner
> World Championships \>65 \>50, Individual World U20 - Gold (i.e.first after tie-break)
> Continental Individual Championships - Gold

In other words, only results which pretty much require you to already be a strong GM.

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Tags: fide, tournament, elo, grandmaster, titles
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# Question
Title: What is a good approach to conduct a round robin event for 20 players in order to select top 6?
I need to have a selection event for **20** players to select **6** players for a team. Plan is to have a **round robin** event since it is fairer compared to a swiss event. Then each player will have to play 19 games. Also the plan is to have 1 hour for each side without increment.

If I breakdown rating wise
**1800+** count = **4**
**1800-** count = **16**

**1700+** count = **8**
**1700-** count = **12**

**1650+** count = **9**
**1650-** count = **11**

**1600+** count = **10**
**1600-** count = **10**

**1500+** count = **15**
**1500-** count = **5**

What would be a good approach to conduct this event? Should I have all 19 rounds? Or is it better if there be 2 rating group tournaments where selected players of lower rating stage get promoted to higher rating stage tournament.

This sounds like an opinion based question, but I would appreciate if someone help me with some insights.

# Answer
To get the fairness of a round-robin without *quite* so many games...

First, separate your players into 2 groups of 10. I'd suggest making the groups each have a good mix of players rather than having a "strong" and "weak group, although that's not strictly necessary. Have them play a round-robin in the group. Top 6 advance. This part will take 9 rounds. (If someone can't get in the top 6 in the smaller group, they weren't going to get top 6 overall, so it's safe to eliminate that player.)

Now you've got 12 players left. Have them play a new round robin - BUT - if any players had played in the previous round robin, you use that result instead of having them play again. That way, instead of this part taking 11 rounds, it will only take 6 (since everyone will have 5 games already played.)

9+6=15, so this only takes 15 rounds instead of 19, and nobody is going to get eliminated just because they faced stronger opponents.
> 4 votes

# Answer
A round robin is not *that* much fairer than a Swiss. There are lots of solutions you could try and, as you say, it is pretty much a matter of opinion. I would suggest a 5 round Swiss followed by a 5 round, 6-player round robin where the 6 players in the round robin are the 6 players finishing in places 4 through 9 in the Swiss. Then pick the first 3 in each tournament.
> 1 votes

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Tags: fide, tournament, swiss-pairing, tournament-directors, round-robin
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# Question
Title: Why do chess puzzles need a unique solution?
Why do chess puzzles need a unique solution? This is different from real games, where such situations do occur, but more frequently, there are multiple avenues to success. Contrary to what one might think, that makes chess puzzles **easier**, not harder! I have solved countless puzzles only because I knew that there is one and only one solution and therefore could exclude moves that I would have needed to consider in a real game.

Especially in some cases, where there are multiple different mates, all solutions should be accepted. Adding such puzzles in a set would lead to better and more realistic training. Also, practical positions may be added where the task may be to play until a certain evaluation threshold is reached or held for a certain number of moves against an engine. Why is tactical training today so "unrealistic"?

# Answer
> 19 votes
If someone says to me: "Let's meet at (mumble) on (mumble)", I may respond: "Sorry I didn't catch that."

Tactical puzzles and artistic problems are both (in different ways) about communicating a message, and if the solution is not essentially unique, then the message is unclear.

Uniqueness then becomes a thing in its own right. In a puzzle, it can simplify the automated response, which can just focus on a single line. In a problem, it becomes an aesthetic property: how wonderfully unlikely in a certain position that the correct sequence of moves is unique!

It's perfectly valid (and fun!) to use the property of uniqueness to prune the search space when solving. Solving is a way to learn and appreciate, and difficulty of solving may be a virtue in both puzzle and problem. However this difficulty is subordinate to the nature of the solution. I can legitimately profit (although less) from a puzzle/problem by just reading the solution.

# Answer
> 11 votes
> Why do chess puzzles need a unique solution?

Because those are the rules. The governing body, the World Federation of Chess Composition, sets the rules. Their latest Handbook of Chess Composition includes a Codex where the rules are laid out.

Here are the relevant articles:

> **Article 8 - Author's Solution**
>
> Every chess composition must be capable of being solved only by the author's solution. Special features of the author's solution (such as multiple solutions or setplay in helpplay problems) should be expressly stipulated.
>
> **Article 9 - Cook**
>
> A chess composition is called cooked if it has a solution that differs in its first move from the author's solution.
>
> **Article 10 - Dual**
>
> A dual is said to occur if, after the first move, there is more than one method of satisfying the stipulation.

# Answer
> 9 votes
I'll have to disagree with the premise here. They don't need a unique solution.

For a matter of fact, some Chesstempo tatic puzzles have sub-optimal solutions, but if they still reach a treshhold evaluation (+-1.5 if I recall correctly) you won't fail or pass the puzzle; Instead a blue box will tell you that although that is a winning move, you should keep trying finding the best one.

# Answer
> 9 votes
Don't look at chess puzzles as a way of training for competitive chess. Chess problems are a genre of their own. A good chess problem is a piece of art.

By requiring a unique solution we place an extra constraint on the puzzle, making it more valuable. This constraint makes it even more difficult to craft a nice puzzle, and we appreciate that.

See https://sportstar.thehindu.com/magazine/chess-problem-an-art-form/article29710563.ece

# Answer
> 6 votes
Basically for the same reason that we're not impressed by a win by queen sacrifice if there was also a pedestrian one- or two-move mate.

There *are* chess problems that deliberately have more than one solution, often to complement each other in some way. This usually happens in helpmates (which are probably of little or no interest to players seeking "training") but they're occasionally seen also in direct-mate problems.

# Answer
> 4 votes
I can think of one puzzle that doesn't and can't have a unique solution, but which of the two possible solutions is correct and which is wrong depends on information that can't be derived from the board itself. It's from Smullyan's "Chess Mysteries of Sherlock Holmes" the chapter "Thoughts of a Logician", so I guess it falls under

> Article 8 - Author's Solution
>
> Every chess composition must be capable of being solved only by the author's solution. **Special features of the author's solution (such as multiple solutions or setplay in helpplay problems) should be expressly stipulated.**

# Answer
> 1 votes
Puzzles are usually intended to be hard or at least challenging. Puzzles with multiple solutions tend to be easier since one can arrive at one though multiple avenues. People who design or choose to present puzzles don't want puzzles that are trivial. So the result is that most tend to have one unique solution.

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Tags: problems, tactics, training, puzzles
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# Question
Title: What is going on with FIDE's latest rapid and blitz ratings? Some players are more than 500 points higher in one month!
It's the last day of September and the provisional rating list for October has been released. There are some very strange ratings changes in that ratings list. Sri Lankan IM LMST De Silva played no FIDE rated rapid or blitz games in September but his rapid rating has risen from 1751 to 2416. Similarly his blitz rating has risen from 1727 to 2416.

What is going on?

# Answer
> 4 votes
Checking the latest FIDE Handbook, there is a new section, FIDE Rapid and Blitz Rating Regulations effective from 1 October 2022. However this is virtually identical to the previous section, FIDE Rapid and Blitz Rating Regulations effective from 1 January 2022 till 30 September 2022.

It seems there is a newer version still of the rating regulations for rapid and blitz which hasn't quite managed to get properly linked from the main documents.

This says:

> **1. Rapid & Blitz**
>
> It was submitted a proposal to the Management Board 11/07/2022 to consider:
>
> * **A one-off rating change to Rapid and Blitz**
> In the rating list published on 1st October, 2022, there will be a one-off change to the rapid and blitz ratings of players who have them:
> * If the player is unrated in rapid or blitz, then they remain unrated in rapid or blitz
> * If the standard rating is more than 100 points higher than one of the other ratings, then that rating is moved up to: standard rating minus 100 points
> * If the standard rating is 100 or less points higher than one of the ratings, then the player retains their rating

IM LMST De Silva's rapid and blitz ratings were a lot more than 100 points lower than his standard rating and so have been moved up to be 100 points less than his standard rating.

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Tags: fide, rating, blitz, rapid
---


# Question
Title: What is the best Chess Engine to practice latter Middlegame and Early Endgame
I have taken a break from chess for while now, and I am hoping to make a comeback soon. I want to brush up on my latter Middlegame and Early Endgame.

I want to start by analyzing recent GM games. What is the best engine as of now for this task?

# Answer
Improving our middlegame and endgame is a task that lasts our entire life. For that reason, please do not expect quick results whatever you do. Chess is one of the most difficult challenges for the human mind. We need to improve step by step, day by day. For training it is better to study books written for experts. Which one? Depends on your level. For example, to improve our endgame, ***Chess Fundamentals, by José Raúl Capablanca*** would be excellent for players that are at the beginning of their career, but ***Mark Dvoretsky's Endgame Manual*** would be appropriate for more advanced players. ***After you have studied the endgame, you can practice it with the latest version of Stockfish that is available on lichess.org for free*** (Level 8 never makes mistakes. Level 1 makes mistakes in all the moves. In the middle of the spectrum, you find levels 7, 6, 5, 4, 3, and 2. Pick the level that you like the most). Same can be done with a strategy book, for example, ***The Giants of Strategy, by Neil McDonald***. Equal formula with a tactics book. My favorite is ***Combinative Motifs, by Maxim Blokh***. ***The website Chessable integrates the e-book and the engine, so you can do both on their website***. When I analyze my games, I use the newest version of Stockfish on lichess.org, but you need to give it enough hardware resources and enough time if you want a good analysis. ***You can always search with Google: lichess+analysis+board.*** But currently, this is the link: https://lichess.org/analysis
> 1 votes

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Tags: engines, analysis, endgame, strategy, software
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# Question
Title: What is the DTM in the following tablebase position?
```
[Title "Black to move"]
[fen "8/8/6k1/8/1N3R2/1P6/K1P5/4q3 b - - 0 1"]

```

or WHITE King on a2 Rook on f4 Knight on b4 pawns on b3 c2.BLACK King on g6 Queen on e1 BLACK to move. I know from other sources this position is winning for White, but what is the DTM and the relative line? Lomonosov is not working in my country.

# Answer
> 1 votes
Check the following link

https://syzygy-tables.info/?fen=3q4/5P1K/6P1/2R3N1/8/1k6/8/8\_b\_-\_-\_0\_1

hope This is Helpful

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Tags: computer-chess
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# Question
Title: Is Sadler's 2000 book Queen's Gambit Declined focused on white or black?
I'm looking for QGD repertoire book as Black. Would Sadler's Queen's Gambit Declined fulfill this, or is it focused on White?

# Answer
I got pointed to this topic by a friendly chatter at the TCEC. In principle, Brian is absolutely right - an opening book 20 years old is really going to be missing some stuff and certainly won't give you the complete modern picture of the opening. In the specific case of the QGD book, there are some parts of my book that are still relevant and still very useful - in particular about the typical pawn structures that you can encounter in the opening. I once had the privilege of studying for a couple of weeks with the great trainer Mark Dvoretsky and he gave me an amazing overview of how to play the Carlsbad structures from both sides (when White plays cxd5 and Black replies ...exd5). That went into the book, and I think it's timeless advice! Whatever you do, you should get a modern course as the basis, but if you're looking later for some extra insight into typical positions (maybe once you've got all your lines sorted out) then this is one of the extras you could think about! Hope that helps! Best Wishes, Matthew
> 9 votes

# Answer
I haven't read the book but from a quick view at the first few pages it looks like it comes from a White perspective, at least when it comes to "completion" (it covers several options for Black from the same position, while it sticks to one recommendation for White).

This doesn't mean the book is useless if you want to study the QGD for Black though. It can give you an overview and some examples of the options you have and help you choose the most practical one.

As for the opinions that old opening books are not useful anymore today, well, it depends. Some lines may be outdated and need revision or further analysis if you want to play them at stronger levels, but you can still get a lot of knowledge about common themes and middlegames arising from the QGD. At lower levels you may even do well with theory that is a century old specially considering the QGD does not rely on too many "critical" lines.

For instance, in the QGD, you'll find much more use in learning how to play isolated "d" pawn positions and Karlsbad structures than in studying the exact best continuation in most lines. It all depends on your level though, could you give us an approximation of your current Elo?
> 3 votes

# Answer
@InertialIgnorance gave you excellent advice. I agree that the "Move by Move" series is excellent. Without a doubt, start with "The Queen's Gambit Declined: Move by Move, by Nigel Davies." About your question, Matthew Sadler is a genius! And the book won the Book Of the Year award in 2000 from the British Chess Federation. How can you go wrong with that? ***Of course, when a book is not new, learn ideas, not moves.*** Also, evaluate the lines using Stockfish because sometimes an important detail has not been analyzed. This trick works for old and new books as well. About another part of your question, Sadler authored the book taking into consideration both sides. He gave ideas for White and Black. At the end of each chapter, he made a summary. The image that is above is a good example that he took both sides into account.

***However, the study of openings is one of the most difficult parts of chess training. I suggest my students focus on strategy, tactics, and endgames, unless they are fighting for the international master or the grandmaster title.***

For openings, I suggest to my students that AFTER they finish their games to compare their moves with the suggestions that are in Nunn's Chess Openings. It is an old book, but good enough for players that have less than 2000 ELO rating points. You can find used books of this kind on eBay for $10. Nunn's Chess Openings has almost all the possible openings that exist.

If your rating is above 2000, in addition to comparing your moves with Nunn's Chess Openings you should compare and analyze your moves with a chess trainer (some chess trainers charge only $10 per hour), and with the most modern version of Stockfish that is available for free in www.lichess.org Here is the link: https://lichess.org/analysis It is important to notice that to get excellent quality in the analysis, you need to provide enough hardware and time to Stockfish.

***Additionally, for openings, I like the books from this publisher: qualitychess.co.uk/sections/1/opening***

***One of my closest friends who is a FIDE Grandmaster and writes for the best chess magazines of the world suggested me Chess Publishing that has the best information for $19.50 per year:*** https://www.chesspublishing.com/content/7/index.htm

***Chessable offers a thirty day money back guarantee. So, I suggest to try with Chessable.*** They also offer some free courses in the Queen's Gambit Declined: https://www.chessable.com/courses/s/Queen's%20Gambit%20Declined

I like also Modern Chess. They offer some free material that you can analyze. https://www.modern-chess.com/chess-databases?database\_author=&database\_opening=Queen%27s+Gambit+Declined&partner=

ChessBase has some good video courses as well: https://shop.chessbase.com/en/search?query=Queen%27s%20Gambit%20%20Declined&cat=0

New In Chess also has some good material: https://www.newinchess.com/catalogsearch/result/?q=Queen%2BGambit%2BDeclined

***In addition to that, nothing better than studying chess in general, and openings, is to play the opening in correspondence chess with white and black pieces.*** Sometimes thematics tournaments are available. My favorite website is Lechenicher SchachServer, that is 100% free: https://www.chess-server.net/en/ Lichess also has correspondence chess.

***Again, my advice is to prioritize endgames, strategy, and tactics, unless you are fighting for the international master or the grandmaster title. Good luck with your chess journey!***
> 0 votes

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Tags: books, queens-gambit-declined
---


# Question
Title: Why does Stockfish suggest this move (25. Qxa6?)
In this position, why does Stockfish suggest the move 1. Qxa6? Also, after 25. ...bxa6, Stockfish also suggests 26. Rd7+, which is followed by 26. ...Bxd7 and 27. Rxd7+. White would just have traded a queen and rook for a rook and bishop. In this position, however, Stockfish still gives an evaluation of +3.15.

I find it difficult to accept that this is the best move for White.

```
[Title "Current position"]
[FEN "2b2q1r/1p4k1/r3n2n/p2RPpN1/P7/2N3PP/1PP1Q3/3R2K1 w - -"]
[startply "48"]

1. d4 a5 2. Nf3 h5 3. e4 d6 4. Bc4 e6 5. Nc3 Be7 6. O-O c6 7. a4 Na6 8. Qe2 Kf8 9. Rd1 d5 10. Bb3 g6 11. Bf4 Kg7 12. Be5+ f6 13. Bf4 g5 14. Be3 h4 15. h3 Nh6 16. e5 f5 17. g3 hxg3 18. fxg3 c5 19. dxc5 Nxc5 20. Bxd5 exd5 21. Rxd5 Qf8 22. Bxg5 Bxg5 23. Nxg5 Ra6 24. Rad1 Ne6 25. Qxa6 bxa6 26. Rd7+ Bxd7 27. Rxd7+

```

# Answer
> 17 votes
After 27.Rxd7+ there's only 5 possible responses.

* 27...Qe7 is plainly bad due to Rxe7+.
* After 27...Qf7 Black is obviously losing the queen, but White can do better than taking it right away. 28.Nxe6+ takes advantage of the pin, gaining the knight *before* taking the queen with the rook. (And then after 28...Kg6 - White will fork king and queen with the knight if Black plays anything else - White can throw in 29.Nf4+ if they want, which defends h3, blocks Black's pawn on f5, and supports an e6 push.)
* After 27...Nf7, 28.Nxe6+ forks the queen.
* After 27...Kg8, 28.Nxe6 threatens the queen and also threatens Rg7# if the queen stops covering g7. (Note that the knight on e6 also covers c5 to prevent the queen from escaping with a check.)
* Similarly, after 27...Kg6, 28.Nxe6, White threatens Rg7+ Kh5 Nf4# if Black were to retreat the queen.

So, Black doesn't actually get to keep that queen. White then hopes to win the much-simplified position using all those pawns.

# Answer
> 9 votes
TLDR: Stockfish analyzed to quiet positions resulting from the position you posted and then statically evaluated them to be at least +3.15 evaluation for white assuming best play from black. I think this is counterintuitive to you because you stopped before getting to quiet positions and statically evaluated too early!

**Explaining How Engines Work**

I'll take the approach of explaining a bit about how the engine works internally, how that differs from the analysis you provided in your post, and how those things taken together explain why it chooses this line and why it seems counterintuitive to you. Stockfish (and every engine I know of) does two main things: 1) search, where it plays out possible lines/variations, and 2) evaluation, where it assigns a numerical value to the position in a search. The evaluation method used is called "static evaluation", which is basically a mapping from the board state to a score *without regard* for what the next move or moves could be, or even whose turn it is. It involves things like counting material and also assigning numerical values to positional features like how many squares your pieces can go to and a vast array of complex material/square patterns. So for example if we have 1. e4 d5 2. exd5 * and the engine is asked to do a static evaluation in that position, it would see that white is a pawn up, and assign an evaluation of about +1 for white; a version of this static evaluation function is available online and that is what I have linked above. *However*, we know that +1 is incorrect in this position, because 2...Qxd5 is coming, after which material is equal again. So, it is not enough for the engine to statically evaluate the position; in fact it must choose the right moment to statically evaluate the position, otherwise it will make these kinds of mistakes. So when is a good time to statically evaluate, and when is a bad time? In human play we call the positions in which static evaluations are reasonable as "quiet" positions. In other words, when all tension is removed, when all pending captures are completed, when all tactical or forcing sequences are resolved, we arrive at a quiet position, and *that's* when you should statically evaluate the position. When the engine does this, it is called quiescence search.

You stopped at 27. Rxd7+ and did your own form of static evaluation, which was to count material. However, the engine realized that this is not a quiet position; indeed, there are still forcing tactical lines to concretely calculate here that involve checks, captures, threats, forks, etc., and other answers have provided that analysis. In every case, after the engine explored all those lines until it got to quiet positions, only then did it statically evaluate and decide that white is better by about +3 with best play from black.

# Answer
> 4 votes
Since the answer by D M, while correct, gives an incomplete analysis of the position, I lengthen the variants somewhat such that even a beginner will see there is no escape for Black. Only the last two variants make sense for Black.

27...Kg8 28.Nxe6

* a) any: Nxf8, which even protects the Rd7 after 28...Rh7 (this is so bitter)
* b) any Q: Rg7#
* c) 28...Qf7 29.Rd8+! Kh7 30.Ng5+ followed by Nxf7, again protecting the wR. White is a ton of pawns up.

27...Kg6 28.Nxe6

* a) any: Nxf8
* b) any Q: Rg7+ and Nf4#
* c) 28...Qg8 29.Nd5!! and Black can only choose between a fork on e7 if Nh6~ protects against Ndf4# or a fork on f4 after 29....Qxe6. White gets all material back and is a ton of pawns up.
* d) 28...Qf7 29.Nf4+ and now
* d1) 28...Kg5 29.h4+ Kg4 30.Rxf7 Nxf7 31.Kg2. Now 31...any 32.Nd5 or 31...Rc8 32.e6 Ne5 33.Nd1 Rxc2+ 34.Nf2+ costs Black at least the exchange so White, you guessed it, is a ton of pawns up.
* d2) 28...Kg7 29.e6! Qxd7 30.exd7. Now the fork on e6 forces Black to 30...Nf7, otherwise the exchange is gone and White...you know the deal. :-) Or 30...Kf7, which, as 30...Nf7, is answered by 31.Ncd5. Now you must play out a lot of variants where Black tries to gang up on the Pd7 with K+R+N. Spoiler: Fail, due to more random forks. White corks a N to c5 or e5 and protects it in time with K or P. (Here the analysis might be extended until noone can deny Black can't get the Pd7 without giving the exchange, so Black is tied up forever and White wins with youknowwhat. OTB I probably would have calculated until there and evaluated it as "good for White" - except that I can't calculate or find Nd5!!)
* d3) 28...Kh7 29.e6 Qxd7 30.exd7 e.g. Rd8 31.Ne6 Rxd7 32.Nf8+, Black throws the board against the wall and screams to the sky "I %&$§ING HATE KNIGHTS!!!"

Hooboy. This could have been a game of mine, my knights tend to give the opponent knightmares...

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Tags: analysis, stockfish
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# Question
Title: How to study highly theoretical openings like the Najdorf, the Grünfeld, or the Ruy Lopez
So I'm probably not at the stage where I'm ready to do this yet, but I'm curious. I know that some openings (like the Najdorf, the Grünfeld, and the Ruy Lopez) are considered highly theoretical openings where knowing the theory is very important, but I'm kind of at a loss as to how to study them. I know the idea of looking at an openings database or plugging positions into Stockfish to see what it likes, but the weakness there is I don't know the ideas that the masters/engines have and how to apply that to my own game.

So, how do you recommend:

1. Learning both the theoretical moves and the ideas behind them; and
2. Learning how to take advantage of non-theoretical moves by your opponent?

# Answer
> 3 votes
There are a lot of tools on the internet to help with this (Sites like chessable, aimchess, etc). Their purpose is to do all the things you described above. Besides that, there are a lot of opening books that are well written and explain the lines and plans in detail, like why some lines are good and why some other lines are bad.

Finally, try these openings yourself in games! Experience is a really big part of learning too and can help you gain an instinct almost on what to do in critical main lines and/or when your opponent plays sub-optimal moves.

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Tags: opening, theory, study
---


title: How many more squares can you attack?

text:
# Question
Title: How many more squares can you attack?
(Inspired by this cool problem)

Let’s say it’s White to move. Let A = the number of squares currently attacked by White, and B = the number of squares attacked by White after White’s next move.

> What is the maximum possible value of B - A?

**A “attacked” square’s definition is just as you’d expect.** More rigorously, a square is attacked by White if, after Black skips the next move, a White piece can legally capture anything on that square. Specifically, if it were empty, then after teleporting a dummy black piece onto that square, a White piece must be able to legally capture that dummy piece. (A dummy piece does not attack). If it were occupied by a white piece, then it must be legally defended by another white piece (the sequence “black captures the white piece with a dummy black piece, and white recaptures the dummy piece with some white piece” must be legal). If it were occupied by a black piece, it must be able to be legally captured by a white piece.

For example, in the linked problem above, we have A = 26 and B = 58. This means B - A = 32, which is really high. But is this the best we can do?

Another example: after opening moves `1. e4 c5 2. Bc4 a6 3. Nf3` we note that Black’s c-pawn attacks `b4` and `d4`, but he does not attack `f7`, because the King cannot move into check. Furthermore, after a random move (say `3. … h6`), `f5` is attacked by White’s e-pawn.

In the solution, preferably, the “current position” should be legal, but if there’s a really nice illegal solution we should see it too.

# Answer
> 4 votes
The original problem may be reduced to

```
[Title "White to move"]
[FEN "5nRB/6PR/8/8/8/8/8/k2K4 w - - 0 1"]

```

White controls f8, h8, g7, h6 to h1 (6 squares) and 5 squares around the king, for a total of 14 squares.

```
[Title "After gxf8=Q"]
[FEN "5QRB/7R/8/8/8/8/8/k2K4 w - - 0 1"]

```

White now controls row 8 (8 squares), row 7 but h7 (7 squares), 4 squares on row 6, 5 on each of the three next rows, 7 squares on second row, 6 squares on first row, for a total of 47 squares.

Thus B - A = 47 - 14 = 33.

In the example given in the original post, I count A = 26 and B = 58, thus B - A = 32. Or, if you do not count squares c2, d2, f2 in your problem as attacked by white, then you would have A = 23 and B = 55, thus B - A = 32 still.

# Answer
> 3 votes
```
[Title "White to move"]
[StartFlipped "0"]
[fen "1q4Q1/P7/8/8/4B3/8/5k1K/R7 w - - 0 1"]

1.axb8=Q

```

In the diagram position, WTM controls 4 squares: b8, g3, h3, h1. After 1 axb8=Q, White controls 48: a8-h8 (8), a7, b7, c7, f7, g7, h7, a6-e6 (5), g6, a5, b5, d5, e5, f5, g5, a4, b4, c4, f4, g4, a3, b3, d3, f3, g3, h3, a2, b2, c2, g2, b1-h1 (7).

A=4. B=48. B-A=48-4=44.

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Tags: problems, mathematics, retrograde-analysis, attack
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