Questions tagged [evaluation]

The evaluation of a given position

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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 ...
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3 votes
0 answers
198 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. ...
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0 votes
2 answers
196 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
123 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 ...
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2 votes
2 answers
104 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 ...
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4 votes
0 answers
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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"] [...
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1 vote
1 answer
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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/...
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4 votes
4 answers
181 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 ...
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7 votes
1 answer
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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 ...
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2 votes
0 answers
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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 ...
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2 votes
2 answers
98 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 ...
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4 votes
1 answer
203 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 ...
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3 votes
1 answer
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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 ...
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  • 88
1 vote
2 answers
153 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 ...
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  • 181
11 votes
1 answer
974 views

Why is this position in the 3.d4 d5 Petroff equal?

I'm trying to learn some theory about the Petroff and was reading about the 3.d4 d5 sideline. Eventually, the position below is reached. [FEN ""] 1.e4 e5 2.Nf3 Nf6 3.d4 d5 4.exd5 exd4 5.Qxd4 ...
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  • 435
5 votes
2 answers
152 views

How to evaluate whether a position will result in a draw vs a decisive outcome?

Suppose 2 positions both have 'equal' evaluations according to the engine, but the first position has strong, easy-to-spot moves which lead to a drawn endgame, whereas the second game is extremely ...
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7 votes
3 answers
420 views

What do chess engine evaluation scores (+1.3, -3.2) really mean?

I know that chess engine evaluations like +1.3 intuitively mean that White is evaluated to have an advantage equivalent to 1.3 pawns of material, or that -3.2 means that Black is evaluated to have an ...
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  • 261
12 votes
1 answer
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Does blitz change the relative value of position vs material?

The way I see it, true gambits trade material for position, which in turn could give you opportunities to regain more material. However, in blitz play, you are less likely to notice those ...
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2 answers
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Techniques used for Stockfish engine selectivity

Example puzzle (I'm sure there are numerous that fit this bill): [FEN "rnbq3r/pppp4/3b1pkp/5p2/2BP4/4P3/PPP2PPP/RN1QK2R w KQ - 0 1"] [Site "Earth"] [White ""] 1. Qh5+ ...
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  • 171
10 votes
3 answers
3k views

Why is this seemingly quiet and normal position actually -3?

rnbqkbnr/pppppppp/8/8/4P3/8/PPPP1PPP/RNBQKBNR b KQkq - 0 1 [Event "Casual Blitz game"] [Site "https://lichess.org/GETmjlLj"] [Date "2021.08.15"] [White "WMArsyHuda&...
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3 votes
2 answers
183 views

How do you evaluate this position?

rnbqkbnr/pppppppp/8/8/4P3/8/PPPP1PPP/RNBQKBNR b KQkq - 0 1 [Date "2021.08.14"] [Result "0-1"] [UTCDate "2021.08.14"] [UTCTime "22:01:55"] [...
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  • 655
1 vote
1 answer
190 views

Detailed Stockfish Evaluation Function

Stockfish contains the nice 'eval' command that prints out the detailed score of its static evaluation function. It regards Mobility, Material, Bishop, Rooks, etc. However, I was wondering if there ...
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8 votes
2 answers
2k views

Why is h4 much better than h3?

rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1 [Event "Rated Rapid game"] [Date "2021.08.09"] [Result "0-1"] [Variant "Standard"] [TimeControl &...
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  • 655
5 votes
2 answers
362 views

Examples where top engines in a tournament match don't agree in evaluation

I'd like to know about computer games of some recent tournaments where two top engines diverge in evaluation of a position, in the sense that both think are winning the game (or both losing). I saw ...
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9 votes
6 answers
4k views

Why is 11. .. h6 such a bad move?

rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1 [Event "?"] [Site "?"] [Date "????.??.??"] [Round "?"] [White "?"] [Black "?"] [...
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3 votes
2 answers
176 views

Can this '+3.9' advantage be converted to a win?

I reached this endgame, which Stockfish 10+ evaluates as +3.9, but failed to convert it to a win. I feel that it may be a draw after all. Is that the case? [Title "White to move"] [FEN "...
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1 vote
1 answer
52 views

How to score a certain move in a PGN, for how well opening theory is followed

I am making a bot that plays opening moves from a PGN. When the player reaches a position out of PGN, I want to give a score to the player how well he followed the PGN. What kind of statistics can I ...
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13 votes
2 answers
1k views

Is there an engine evaluation technique that factors in 'time'?

An interesting game played out between Wesley So and Levon Aronion1: [title "Wesley So vs Levon Aronian"] [fen "rn4k1/p2bP1b1/2q5/1pp2p1Q/2p5/8/PP3PPP/3R1RK1 w - - 0 1"] So was in ...
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  • 1,751
20 votes
2 answers
5k views

Is this a draw despite the Stockfish evaluation of −5?

I reached this position as Black: [Title "Black to move"] [FEN "8/8/8/3q4/6kp/7R/6P1/6K1 b - - 3 46"] And I felt that I cannot make any progress and so it feels like a draw. ...
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2 votes
3 answers
251 views

Why are lots of different moves usually considered equivalent in the opening, but not in the middlegame?

When you go to websites like chess.com and analyze your games, you'll notice that most of the first moves are marked as being "book moves"—which I assume are considered equivalent to each ...
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5 votes
1 answer
2k views

Why is this position considered to give white a significant advantage?

In this position, black's king is safe, has a secure queenside pawn structure, and has taken out white's left pawns and is up 2 points of material. Despite this, lichess evaluates this position at +3....
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  • 193
7 votes
3 answers
1k views

Why is this "slow move" with the king a good move?

rn1qkb1r/1p3pnp/p1p1p1p1/3pP3/3P2P1/2NBBQ1P/PPP2P2/2KR3R w kq - 0 13 Stockfish (depth 30) says the best move is Kb1 with +1.5 evaluation. I'm having trouble to understand why. The a2 pawn is not ...
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1 vote
0 answers
163 views

Contempt factor [closed]

I have a question concerning the contempt factor of a chess engine, that i am writing, and thought that this forum would be the best one to ask it in. The contempt factor is a way of deincentivizing ...
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5 votes
2 answers
1k views

How come it's actually Black with the advantage here?

I was analyzing a recent game of mine, and I noticed something interesting. After I blundered back a bishop on move 16, the evaluation was -3.4, which is still strongly winning for Black. [White "...
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7 votes
3 answers
611 views

Big changes in engine's evaluation after considerable time

I hope this question hasn't been asked before. I am looking for some examples where, say, the latest Stockfish or Komodo engine (or possibly some of the top NN engines) evaluates a position as plus or ...
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9 votes
3 answers
2k views

Why is it a mistake to capture the forked rook?

In a recent game, I forked a queen and rook with a knight. After seeing no immediate threats from 8. Qf4 I immediately captured with 8. ...Nxb3. Apparently this was quite a mistake (a 213 centipawn ...
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  • 369
4 votes
2 answers
454 views

Which open source chess engine has the most positional understanding?

Most open source chess engines with hand-tuned evaluations are known for their innovations on search (Fruit, Stockfish). I was inspired by HIARCS' generally more human-like play and the fact that ...
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2 votes
1 answer
252 views

The best move in this Crazyhouse position according to Stockfish

I just played my first few games of Crazyhouse, and I really don't understand it. At one point I had this position. [Title "White to move"] [FEN "r2q1rk1/pbb2pp1/n1p1p2p/1p1nP3/2pPN3/...
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  • 2,264
3 votes
3 answers
1k views

Stockfish Evaluations

I've been getting Stockfish to analyse lines of the KID, and the evaluation gives a score of around +1.5: White has a big advantage. How come this is true, when the KID is a playable(and good) opening?...
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1 vote
2 answers
1k views

Lichess endgame evaluation

Why is it that Lichess, and other engines for that matter, give a non-zero evaluation score on an endgame position that should be either a draw or a win for one of the sides (given perfect play)? For ...
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  • 137
3 votes
1 answer
243 views

CNN autoencoder for feature extraction for a chess position

I'm currently building a chess engine in my free time while entering my second year of my master's studies in computer science. For a class we need to perform a litterature survey of a topic and ...
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29 votes
4 answers
7k views

Should a chess engine be aware of opposite-side castling?

I often hear chess experts and chess articles say that when opposite side castling occurs on the board that it is important to launch an attack on the enemy player as fast as possible. Up to the point ...
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  • 616
3 votes
1 answer
1k views

Deducing brilliant sacrifices

Is it possible to deduce brilliant sacrifices by analyzing a match's PGN along with the corresponding evaluation score after each move? If not, what other non-visual information would be needed to be ...
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  • 137
2 votes
0 answers
156 views

Scid vs PC Score Graph

Is it possible to modify the source code to change the display of the score graph so that you are always at the bottom? Currently, the player playing White is always at the bottom.
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  • 137
3 votes
2 answers
446 views

How to get static evaluation from Stockfish in case that a king is in check?

I am working on a program that should recognize the difference between human and computer players. For this purpose, I need some parameters. A part of them would be the individual values of the static ...
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  • 61
4 votes
1 answer
123 views

Trapped Rooks: Does Stockfish penalize more if the king can't castle temporarily?

In this talkchess thread, they discuss trapped rooks and castling rights. In post #5, user @Lyudmil Tsvetkov posted: I would give at least some 10-15cps for temporary prevention of castling. Here is ...
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1 vote
1 answer
171 views

ELO change of engine from pure material to very good evaluation

I am currently rewriting a chess engine with a friend. We decided to first work on the search and only later if the search works really well, we will do some very good evaluation. The engine itself ...
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2 votes
1 answer
89 views

Engine is evaluating the same position at the same depth with different score

My engine is evaluating the same position at the same depth with a different score inside the search tree, is that normal? [Title "depth 1 ply 3 alfa -20 beta -15 score -15 (1.Na3 a5 2.Nh3)"] [FEN ...
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  • 179
5 votes
1 answer
187 views

Move evaluation on armageddon games

I am wondering if there is a Stockfish-like evaluation of moves that could take in account armageddon rules, the rules being that you lose if you draw. I would imagine a strategy of just trading ...
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  • 159
3 votes
2 answers
694 views

Can someone explain the positional advantages for white?

[FEN "3r1rk1/7p/bq2ppp1/p1R5/Pp2P2P/4QB2/1P3PP1/3R2K1 w - - 0 1"] As far I can see, Black’s bishop has more scope than the white one, White has some isolated pawns, and the Black pawns rule the 5th ...
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