Questions tagged [evaluation]

The evaluation of a given position

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Statistical distribution of centipawn losses

I am wondering what function describes best the statistical distribution of centipawn losses in human chess games. (I do not mean the average centipawn loss for a completed game, but losses of single ...
Nikodem's user avatar
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How to train an efficiently updatable neural network (NNUE)?

I've been working on my own chess engine for a while now. It uses standard minimax search. I've trained a convolutional neural network as a static evaluation function, and I've had some good results ...
Nonlinear's user avatar
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3 votes
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Trying to understand evaluation

I'm looking at this position. [Title "White to move: +10"] [StartFlipped "0"] [FEN "r3kb1r/2pnp1p1/p3Bn1p/8/Np1Pq3/4B3/PP21PPP/R2Q1RK w kq - 0 1"] Material is even, and ...
Martin Argerami's user avatar
1 vote
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Training data retrieval

I am currently developing a chess engine which uses minimax algorithm to evaluate chess positions. In addition to this I want to improve my current static evaluation with reinforcement learning. I ...
Martin Šváb's user avatar
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61 views

How do I test my static evaluation function?

I am programming a basic chess AI, within it I have my evaluation function. It is simple, only uses piece square table values, and does basic calculations for the pawn structure and king safety. How ...
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What is this wide split in the Kmoch nimzo between stockfish's evaluation and master-level move choice?

In the Kmoch Nimzo Indian (sometimes called the f3 nimzo) [FEN ""] 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. f3 d5 5. a3 Bxc3 6. bxc3 c5 (6... dxc4!? 7. e4) The move 6...c5 is the most popular ...
Awalrod's user avatar
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Why does Stockfish only gives -28 to a game with only a W pawn and a B rook remaining, while it should be resolved in perfect play?

In this position (W resigned) with only a pawn and a rook remaining Stockfish should have resolved the game and say "Mate in xx" (with perfect play). However Stockfish is said to have ...
Déjà vu's user avatar
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Is there any engine that is capable of evaluating the worth of a single piece in a given position?

The value of any piece is dynamic and depends on many factors in the position. Engines can evaluate the position as a whole with great precision. They are also capable of "understanding" ...
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Rating decreased suddenly without reason, FIDE rating displayed wrongly in the website can anyone have such Problems

My son's rating opened when he played international match during August 2023. The rating was displayed in FIDE website on the last date of August, and it was 1156. Later on September he played another ...
Bio's user avatar
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3 votes
2 answers
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Why is this knight outpost from a Semi-Slav an inaccuracy?

[fen "rn1qk2r/4bppp/p1p1pn2/1p4B1/3P4/2NQPN2/PP3PPP/R3K2R w KQkq - 0 12"] I played Ne5 which I thought was reasonable as it targets c6. But Stockfish 14+ goes from +1.1 to +0.2. What is the ...
qwr's user avatar
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Why is Nf6 a blunder here?

With Nf6, I'm trying to bring my Knight out. If the Bishop takes it, I can take the Bishop with by g7 pawn. Why is this a blunder?
csmathhc's user avatar
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How are piece phase values for tapered evaluation/phase calculation calculated?

On the chessprogramming wiki site for tapered evaluation, there is the following code snippet for how engines calculate phase: eval = ((opening * (256 - phase)) + (endgame * phase)) / 256 PawnPhase = ...
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2 votes
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How to implement Zobrist tables?

I am making a chess engine and trying to implement Zobrist tables into my engine. From what I've read, my understanding is that you first calculate the Zobrist hashcode, then get the modulo of the ...
wdk23's user avatar
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Stockfish evaluation bar like chess.com

I programmed my own chess website and I have Stockfish included (v16) to play against. I’m trying to make an evaluation bar like on chess.com but I can’t seem to figure out how. I thought about using ...
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Comparing evaluation from position after white move to position after black move?

I'm coding a chess engine and have the following problem: I want to only evaluate if the position is quiet, meaning if one side takes a piece the depth should grow by one ply. If then the other party ...
Paul's user avatar
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3 votes
4 answers
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Why 6.Qf3 is bad in this game/position?

I played this game a few days ago with a friend of mine which is quite stronger than me. I also report here the position after 6.Qf3 to clarify a little bit more, in the game I was white: [title "...
ela's user avatar
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2 votes
3 answers
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How do we exactly establish if a position/center is "open" or "closed"?

The question is closely related to this one, but not exactly the same, since in that question the topic is addressed perhaps more from a computer science point of view. During my chess studies I ...
ela's user avatar
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5 votes
1 answer
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Is there any positional assessment that includes a factor for how difficult it is to play the correct moves?

As I understand it, current positional assessments by computers evaluate a position based on optimal play by both players from this point. i.e. a trap moves that bait an opponent into making a mistake ...
Brondahl's user avatar
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Extract evaluation data from Stockfish in Cpp

I am working on a chess player-rating system based on engine evaluations. As part of this I would like to extract evaluation data from Stockfish for the top 10 moves in a given set of positions. ...
Enforce's user avatar
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2 answers
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Why taking the knight on d5 in Alapin Sicilian is not so good for white

I'm going through some preparation of the Alapin Sicilian. Studying the opening I reached this position: rnbqk2r/pp2bppp/3pp3/3nP3/2BP4/5N2/PP3PPP/RNBQK2R w KQkq - 2 8 In which I wonder why it isn't ...
ela's user avatar
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5 votes
2 answers
351 views

Winning position after move one?

Question: There are 400 possible two-ply openings; that is, positions that can arise after each player has made one move. Which of these positions, if any, are winning (either for white or for black)...
Ravi Fernando's user avatar
10 votes
5 answers
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Why doesn't Stockfish announce when it solved a position as a book draw similar to how it announces a forced mate?

I notice that when Stockfish has solved a position to mate it announces that checkmate is unavoidable in some number of moves so it's impossible to mistaken a position Stockfish has solved as a win ...
Anders Gustafson's user avatar
1 vote
1 answer
186 views

A complex eight pieces opposite color Bishop endgame

The position, derivated by a variation of the Alechkine Defense, Four Pawns Attack, is the following: [FEN "3b4/8/1k2B3/6pK/P7/8/6PP/8 b - - 0 1"] Black to move. Stockfish 14.1 NNUE gives ...
Stefano's user avatar
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18 votes
8 answers
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Why don't chess engines take into account the time left by each player?

Firstly, I am not suggesting that there is anything wrong the way engines are implemented at the moment, by analyzing only the current position regardless of time left by the players. This is great ...
ihavenoidea's user avatar
2 votes
1 answer
261 views

Why does Stockfish evaluate this position as completely lost?

After thinking for a minute my copy of Stockfish evaluates the position below as +4.7 for white. Why does the computer hate black's position so much? I know that all things being equal, black should ...
Keeley Hoek's user avatar
3 votes
2 answers
219 views

Why does stockfish make these strange recommendations?

The FEN is: r2qk1r1/ppp2p1p/2n1bn1Q/4p1B1/8/2P4P/PP1NpKP1/R5NR b kq - 0 1 Clearly black is winning because the white bishop can be captured (with a discovery available if white recaptures). However, ...
wim's user avatar
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9 votes
6 answers
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How to analyse positions more accurately as a total beginner?

In this position I thought I was winning with white, like +2 or +2.5. But Lichess Analysis shows evaluation as -1.4. [Title "Black to move after Ne5"] [fen "rn3rk1/1p1b3p/p2n1qp1/3PNp2/...
insipidintegrator's user avatar
2 votes
1 answer
257 views

How many centipawns guarantee winning?

Since the question in this form is somewhat ill-defined, I elaborate on it so it can be solved by experiment: What is the maximum centipawn value you can come up with so that the weaker side holds a ...
Hauke Reddmann's user avatar
7 votes
3 answers
214 views

Can chess engines recognize equivalence between two positions?

The positions [FEN "8/4kn2/4br2/8/8/3Q4/4K3/8 w - - 0 1"] with white to move [FEN "8/8/8/2Q5/1K3bk1/5rn1/8/8 w - - 0 1"] with white to move [FEN "8/2nk4/2rb4/8/8/4Q3/3K4/8 w ...
Anders Gustafson's user avatar
12 votes
3 answers
972 views

Are knights more powerful in Duck Chess?

In the chess variant Duck Chess (full rules), each player moves the shared blocking "duck" piece to any free square on their turn, taking away one or more moves for the opponent. One ...
SE - stop firing the good guys's user avatar
2 votes
0 answers
244 views

What's the theoretical worst average centipawn loss on LiChess?

Since mate is evaluated as a finite centipawn loss, all games have a finite average centipawn loss. I stumbled upon this Reddit r/chess thread where this game has an average centipawn loss of 1971 vs....
Rebecca J. Stones's user avatar
6 votes
4 answers
309 views

Will writing a chess engine help my chess?

At first the premise seems absurd - the computer engine relies much more on brute-force search (Shannon's Type A Strategy) over selecting a few strong lines with heuristics (Type B Strategy). But can ...
qwr's user avatar
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3 votes
1 answer
234 views

Alpha-beta pruning with a silly move

After learning about alpha-beta pruning algorithm for a while, I decided to write a simple chess program. However, when running the program, the computer decides to make a silly move. I don't know ...
Nguyen Hoang Huy's user avatar
2 votes
0 answers
64 views

How do you hide evaluation scores in the arena chess GUI?

Is there a way to hide the evaluation scores while playing a game using the arena GUI?
user32951's user avatar
8 votes
1 answer
873 views

Why do Engines show a fraction for the "Depth" and "Current Node" values?

Forgive me if this has been asked elsewhere, but I've both Googled and searched here at CSE and cannot find an answer. When I'm using an Engine for analysis (in this case, Stockfish 15), I've noticed ...
MikeMitchell's user avatar
10 votes
4 answers
2k views

How would the min max algorithm of a chess engine work in the case of 3 player chess?

I understand that for 2 player chess if an engine is playing white, then the engine uses a min max algorithm, which assumes that black will always make the move that is best for black, or worst for ...
Anders Gustafson's user avatar
3 votes
2 answers
332 views

Imagine your (stronger) opponent plays this Botez Gambit. How to strategise?

My experiment is inspired by Hikaru Nakamura's "Botez Gambit Speedrun". The term "Botez Gambit" refers jocularly to the act of blundering your queen. Let's say you had the black ...
Chris Sanders's user avatar
4 votes
0 answers
304 views

Are engines impaired by the 50-move rule?

Are we missing too much from the 50-move rule implementation to engines, whether HCE (Hand-crafted evaluation) or/and NN (Neural Network)? We know that certain endgames are a win without the rule. ...
JSBach49's user avatar
0 votes
2 answers
312 views

How do I evaluate the value of every piece in Mathematical Chess?

This is Vietnamese Mathematical Chess— http://cotoan.vnvista.com/rules-en.html The board contains 11 ranks and 9 files. Each side has ten pieces, numbered from 0 to 9. The board initial layout is as ...
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1 vote
2 answers
138 views

Help with evaluating this position

rn2k2r/ppp2p2/4bn1p/2bp4/8/1B3N1P/PPP2PP1/RNB1R1K1 w Qkq - 0 1 I am having trouble evaluating this position, I believe the activity of the pieces is equal, besides the week h6 pawn I cannot see why ...
Alyosha OL's user avatar
2 votes
2 answers
659 views

Stockfish NNUE vs handcrafted Evaluation

I read up on Stockfish NNUE and as far as I understand it, Stockfish NNUE was (at least in early stages) trained by positions which were evaluated by the hand-crafted eval. function by stockfish. The ...
Phil3453's user avatar
6 votes
1 answer
163 views

Why do these convergent lines evaluate differently?

I recently analyzed alternative lines for this puzzle on chess.com. [Event "French Championship"] [Site "Val d'Isere FRA"] [Date "2002.08.23"] [Round "5"] [...
Greg's user avatar
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1 vote
1 answer
212 views

Lichess Cloud Evaluation Flaw?

In the following position that's in the Traxler Counterattack: https://lichess.org/analysis/r1b1k2N/ppp1q1pp/5n2/3Pp3/2Bn4/8/PPPP1bPP/RNBQ1K1R_w_q_-_1_9 [fen "r1b1k2N/ppp1q1pp/5n2/3Pp3/2Bn4/8/...
myaccountsgoogol's user avatar
4 votes
4 answers
256 views

How does one determine if a book move is objectively better than another?

For example, I have heard the following statements: After 1. e4 e5 2. Nf3 Nc6, the move 3. Bb5 is marginally better than the move 3. Bc4. Openings moves such as 1. e4, 1. d4, 1. Nf3, and 1. c4 are ...
Zuriel's user avatar
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8 votes
1 answer
306 views

Why does stockfish move quality increase non-monotonically with increasing depth? -- selected moves at depth 3 are worse than depth 1

I have been working on a project looking at how stockfish moves change with increasing computation time (here search depth), and have found something peculiar - namely that the quality of moves that ...
Evan Russek's user avatar
2 votes
0 answers
185 views

How to filter out games with evaluation from large PGN file?

I have a huge 100M games in one PGN file - some % of it is stockfish evaluated, I want to use pgn-extract to extract those evaluated only, Is there a way of doing so? examples of games with and ...
Kamil Czarnogorski's user avatar
2 votes
2 answers
615 views

Python Efficient Board Scoring Function To Use As Placeholder

I'm building a chess engine in Python. I'd like to find a board evaluation function that would be easy to put into my engine as a placeholder while I work on other aspects of the engine first. I would ...
Sam Ragusa's user avatar
4 votes
1 answer
239 views

Analyse a blunder

Black (me) to move. I took the knight at f3 with my knight at e1. However, Lichess analysis shows that this move is a blunder, and suggests to take the bishop at g2 instead. IMO, I am winning no ...
null's user avatar
  • 143
3 votes
1 answer
1k views

Using pgn-extract to output FEN + evaluation

I'm using pgn-extract to convert a PGN database into FEN + evaluations. My goal is something like this: 1. e4 e6 2. d4 b6 3. a3 Bb7 Into this: rnbqkbnr/pppppppp/8/8/4P3/8/PPPP1PPP/RNBQKBNR b KQkq e3 ...
Sam Liu's user avatar
  • 108
1 vote
2 answers
181 views

Why wasn't Ne5 a mistake when I could just win the exchange in one move?

I had this position arise in a game: [FEN "4qrk1/3rppbp/1p4p1/p2P4/1pBP1B2/1P2PN2/5PPP/R2Q1RK1 w - - 2 21"] [White "Kevin"] [Black "lichess AI level 3"] 1. Ne5 {I ...
Kevin's user avatar
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