Questions tagged [computer-chess]

This tag refers to chess games played by computers. If you want to ask a question about those games, use this tag. Otherwise, use the tag [engines].

Filter by
Sorted by
Tagged with
2 votes
1 answer
81 views

Is there a way to get blunders, mistakes and inaccuracies using Stockfish?

Stockfish provides the best moves/lines but is there a command or technique to get inaccuracies, mistakes and blunders? How is this done by lichess or chess.com? They also have the ability to show an ...
  • 121
2 votes
3 answers
158 views

Is the decline in chess strength in a GM as they age similar to their ascension or different?

I mean, given that GMs or other strong players (I choose strong players because their peak rating vs low has "more data" than that of weaker players but it probably relates to weaker players ...
  • 427
2 votes
1 answer
190 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 ...
6 votes
2 answers
283 views

What unusual engines do we have?

Almost all current engines are similar and built for the same tasks (stockfish, lc0, slowchess, comodo...). And I only heard about a few unusual engines Crystal: based on Stockfish but used for ...
  • 71
-4 votes
1 answer
88 views

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 ...
-2 votes
1 answer
114 views

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 ...
4 votes
1 answer
317 views

Are cyborg (human+computer) players really better than the best chess engines?

I saw this rating score chart recently: Is it true that cyborg chess players are (that much) better than the best chess programs by themselves?
  • 896
7 votes
0 answers
373 views

What Elo rating does The Chessmaster 2000 have?

A recent agadmator video pitted The Chessmaster (NES) against Stockfish 14 NNUE. What is more impressive to me is that this chess engine, released originally in 1986 and written by David Kittinger in ...
  • 3,216
1 vote
1 answer
375 views

How do I implement UCI in my Python chess engine?

I have developed a chess engine in Python with negamax, alpha beta and piece square table. I want to "compile" my code into a UCI compatible one so I can load it to Arena GUI, but I have no ...
4 votes
0 answers
102 views

Stack data structure to store chess positions?

One method I thought of for storing chess positions is a stack. This is because when you go one move deeper in the search, you add that position onto the stack, and delete the node when finish, this ...
  • 115
4 votes
1 answer
180 views

Is there a Correspondence Chess ranking on Lichess.org on 2022?

A similar question was posted in the past (2020): Is there a way on lichess to see the Correspondence chess rankings? However, that solution is not working anymore. In my perspective, things have ...
  • 949
4 votes
1 answer
108 views

Is it possible to only generate one color's legal moves?

Let's say I have a position where white is to move, and I need white's legal moves. Is there any way where it is not necessary to generate black's legal moves? You only need black's moves for white's ...
  • 115
3 votes
1 answer
422 views

How to implement programming with board states (turn, en passant squares, castling rights)

From Gigantua, the fastest chess move generator, it says that The same holds true for the castling squares and most importantly the current moving color becomes a compiletime template and not an if ...
  • 115
4 votes
1 answer
383 views

How do you nerf Stockfish to analyze the same position multiple times?

I want to make some statistics by analyzing the same position, multiple times, at different levels of Stockfish. Precisely, I would like Stockfish to analyze a specific position at different "...
  • 43
-1 votes
1 answer
161 views

Why wouldn't the PC take the bishop?

In this scenario, I do not understand why the computer did not do Bxa6. There could be an argument that he did not want to exchange the pieces, if white follows with Nxa6, but if he does not take the ...
4 votes
1 answer
413 views

Lichess stats for average centipawn loss

I am not able to understand the meaning of this stats on Lichess. How can I analyze that and work on my weaker points. Does it mean I make bad Queen moves?
2 votes
0 answers
101 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 ...
1 vote
2 answers
146 views

An interesting question from a Leela vs Komodo blitz game

In a blitz game between Leela zero and Komodo, the following position came up. [title "Leela Zero vs Komodo"] [fen "8/8/2p3k1/4bpp1/2P3P1/4BK1P/5P2/8 w - - 0 1"] With White to ...
  • 389
3 votes
1 answer
373 views

Dataset: Chess Positions and evaluation value

Is there anybody out there who knows about a very good dataset of chess positions (e.g. FEN notation or 64 fields with pieces in it) combined with a Stockfish-like evaluation score? I did find ...
  • 133
1 vote
1 answer
201 views

Average number of moves until checkmate for two players of unequal strenth

Suppose a game is played, until checkmate, between players of unequal strength, say 1800 vs 2800. What would be the average number of moves be for, say, 1000 games? I also ponder 2000 vs 2800 and 2200 ...
-1 votes
1 answer
114 views

Does the strength of computers invalidate fears that chess is "too easy", etc.? [closed]

Many years ago, I think it was Capablanca who said chess was too easy and I think also, long before computers could play a decent, the "draw death" of chess was discussed. But can't ...
  • 427
1 vote
1 answer
117 views

Is it computationally feasible to find a board with proven outcome, reachable in 2 plies?

As is well known, neither the 0-ply game, the starting state, nor 1-ply games, all of white's first moves, have rigorously proven outcomes. Not even first moves for white considered very bad (1. g4) ...
2 votes
1 answer
352 views

Bitboard chess engine design

What are the best approaches to designing a chess engine? What classes/structures should it have? How are they connected to each other? I'm building a chess engine but I often find myself overwhelmed. ...
  • 103
4 votes
1 answer
324 views

Move generation for sliding pieces and Hyperbola Quintessence

I'm working on a bitboard-based chess engine at the moment and I have managed to generate pseudo-legal moves for knights, kings and pawns. However, I'm still trying to wrap my head around sliding ...
  • 103
1 vote
0 answers
197 views

Why is futility pruning causing an Elo drop in my engine?

I'm getting weird results when introducing futility pruning into Blunder. On the one hand, I'm getting a pretty sizeable reduction in nodes, and I'm searching a full ply deeper for some positions (e.g....
0 votes
0 answers
69 views

Are there still "unsolvable" positions for computers, post Alpha Zero? [duplicate]

Yeah, yeah, duplicate... Dupe A Dupe B ...but the times they are a-changing. For example, I tried this "rambling rook" piece by Henneberger, Lichess Stockfish found a #31 on depth 93 or so. ...
3 votes
1 answer
151 views

Is there a way to classify a chess position using algorithms and data science?

Given a position, is there a way we can classify a it, such as if whether there is a pin, fork, or trap, or a mate a mate in 2 or 3? If it is possible, what would be a better approach, an algorithmic ...
2 votes
1 answer
470 views

How do I get Stockfish to write its analysis to a file using a batch file on Windows?

I can get this to work in a Windows Command Prompt window as follows: stockfish_14_x64_modern.exe uci ucinewgame position fen rnb1kbnr/ppp1pppp/8/3q4/8/8/PPPP1PPP/RNBQKBNR w KQkq - 0 1 go depth 17 ...
1 vote
6 answers
441 views

A critical endgame in the French Winaver

This endgame may even be critical of the entire variation. Stockfish 13 on move 34 depth 70/94 11.3 M of six men tablebases suggest a line that lead to the following endgame. [FEN "8/2k5/1p4bP/...
  • 265
8 votes
2 answers
2k views

Is it normal for a chess engine to blunder material if its evaluation is only based on naive material evaluation?

For the past couple of weeks, I've been making a chess engine, and right now I'm working on creating its search and evaluation phases. To start off with, I made the evaluation phase a simple count of ...
5 votes
1 answer
3k views

Looking for polyglot opening books

I understand the Polyglot opening format is open source, but I can't find available opening books for polyglot. I'm looking to use a book to automatically identify (and exclude) opening moves from a ...
1 vote
1 answer
181 views

How to avoid the same opening move in an engine built using Python chess

I created a chess engine using the Python chess library. It has an evaluation function (piece values, piece square values, and capture values) and minimax. Alpha-beta pruning is also implemented. At ...
4 votes
1 answer
877 views

Problems with computing the Zobrist hash for a chess position?

I'm attempting to use Zobrist hashing in my chess engine, but I'm running into some difficulties getting it to work correctly. I'm using the random numbers from this site so I can test my results ...
3 votes
1 answer
381 views

How can a check evasion move generation algorithm be done efficiently?

In my chess engine, I'm attempting to create a strictly legal move generator, instead of generating pseduo-legal moves, then discarding them later in the search and evaluation phase. So far, here is ...
6 votes
1 answer
1k views

How is Stockfish so fast?

I'm currently developing a bitboard-based chess engine for fun and can generate around 5.5 million positions per second on perft tests. I ran the same tests on Stockfish, which can do around 130 ...
  • 121
7 votes
1 answer
382 views

How do computers end up blundering?

I’m trying some practice games against Stockfish level eight. I always lose but sometimes Stockfish makes obviously bad moves and I get ahead. Here for example, Stockfish makes an inaccuracy followed ...
  • 79
2 votes
1 answer
466 views

How can I make my chess engine more efficient?

First, here's some context. My chess engine uses bitboards and works like this: A single gameboard is created as a 2d array at the start of the program. Like this: [[-4 -2 -3 -5 -6 -3 -2 -4] [-1 -1 -...
2 votes
1 answer
385 views

Why did Kasparov resign at 19. c4 in game 6 of the 1997 Deep Blue match?

The game is justifiably famous and is linked here. [Date "1997.05.11"] [Round "6"] [White "Deep Blue"] [Black "Kasparov"] [FEN ""] [startply "39&...
5 votes
1 answer
455 views

Obtain information about a a position from Stockfish

I want to know from Stockfish: All possible moves in a position, a.k.a. a depth 1 analysis with no score. If the king is in check, is checkmated, or if there is a draw. The current FEN string, after ...
  • 301
3 votes
1 answer
314 views

How much does adding an opening book to a relatively weak chess program affect its strength?

Jonathan Schaeffer in One Jump Ahead (via the Chess Programming Wiki): To solve the opening problems of his chess machine, Belle, Ken Thompson typed in opening lines from the Encyclopedia of Chess ...
  • 426
-3 votes
2 answers
148 views

An incredibile endgame

Is the following position [FEN "8/P1R5/K3p3/4k3/B3b3/8/8/1r6 w - - 0 1"] a win ( for White) or a draw? The position above is derived from a variation of Stockfish vs Komodo TCEC Season 19 ...
  • 265
2 votes
1 answer
408 views

List possible moves for player - Haskell implementation

I'm trying to implement a function in Haskell that returns a list containing all possible moves for the player who's up. The function's only argument is a String composed of an actual state of the ...
2 votes
1 answer
161 views

How to measure Leela Chess Zero improvement

I searched Leela website for some statistics about its self-training, the number of games it played with itself in order to assess its progress or to be able to predict whether it is going to win the ...
  • 281
7 votes
1 answer
543 views

How often do hash collisions occur in modern chess engines?

This is a question I am asking for a chess engine I am attempting to create. I have read that engines like Stockfish can look at around 100 million positions per second on a good computer. The code on ...
1 vote
1 answer
214 views

Why does white not play cxd4 here?

I am Black and my opponent is White. Here the computer recommends Rxd4, which I have done (the rook captured bishop here). [FEN "4r1k1/1pp2pp1/p6p/4q3/P2rPn2/2P1QP1P/1P4P1/R4RK1 w - - 0 1"] ...
  • 119
1 vote
3 answers
567 views

Fastest way to generate castling moves in a computer chess engine

I am currently developing a Bitboard chess engine using C++. I am in the process of creating the move generator function. I have completed most of it and only the casting part is left. I have used ...
user avatar
12 votes
3 answers
2k views

How to play computer from a particular position on chess.com app

I started playing chess a month ago and sometimes I would like to play a hard computer from a particular position (e.g., practicing not blundering in openings, or practice winning a won endgame ...
2 votes
1 answer
526 views

Chess engine does not go for checkmate

I have made a chess engine that can play a decent game of chess. Like a lot of engines it uses a minimax search algorithm with alpha-beta pruning. It uses this simple evaluation function to assign a ...
-1 votes
2 answers
333 views

Stockfish vs Leela zero

In the TCEC Cup 7 , Stockfish and Leela Zero played the below position; Is this a win for White or is Black able to defend this position? Black to Play [Event "TCEC Cup 7"] [White "...
  • 129
4 votes
2 answers
2k views

Why didn't the Black rook capture the White bishop?

I am a total newbie in chess. I was playing with an ~intermidiate computer~ as White and made a pretty stupid mistake by playing Bf4. I waved the bishop goodbye, yet Black's rook did not capture it. ...