Questions tagged [engines]
Questions relating to chess engines: any computer program that is able to play/analyze chess positions.
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Why does the computer give me a high accuracy score?
My rating on chess.com is of about 1077 on rapid and today when I won a game against a player with slightly lower rating the analysis results said I played with 73 accuracy according to their best ...
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Could Magnus Carlsen beat AlphaZero given unlimited takebacks? [closed]
Carlsen can't beat AlphaZero in an actual game, but what if we gave him the ability to takeback any blunder or sub-optimal move he makes and try again?
I mean a normal person with no knowledge of ...
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How do I complete this implementation of magic bitboards?
I'm currently coding a chess engine in C++, and have run into a bit of trouble with my magic bitboard implementation.
So far, I have a function that calculates blockerBoards (all the possible pieces ...
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If there is two knight that can go to the same square, how does lichess know which knight I moved in the blind mode?
I just thought about something where two knight can go to the same square. Let say if a white knight is at c3 and a black knight is at b2. They both can go to a4 square. My question is that if I am ...
user26887
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Why does my ability/rating against bots vary?
I've recently started playing chess again and am training against the chess.com bots.
I've been able to blaze through the lower rated bots and started to get stuck around the 1100s with having to take ...
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Why does Stockfish lose against this piece sacrifice in the Berlin Defense?
In a recent YouTube video, Jonathan Schrantz presents an absurd (?) piece sacrifice in the Berlin Defense, which Stockfish seems to vastly underestimate.
The engine evaluation shows around -4, until ...
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What does an equal odds game look like for a GM vs an engine?
This question began an interesting discussion on handicaps for engines that play against GMs:
Engine-invented variations/hypotheticals
This led me to wonder, are there differences in handicaps in ...
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What is the difference between a brilliant move and the best move?
As far as I know, nowadays the chess engines can judge that a move is the best or that it is brilliant (usually denoted by ! or !!). I was wondering what is the precise criterion for this ...
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Engine-invented variations/hypotheticals
After watching a few alphaZero vs stockfish games, I was very intrigued. Clearly, engines can play at a different kind of level, but for the most part the openings seem pretty meta. Nothing extremely ...
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A disagreement between me and my chess engines
In a recent blitz game, I was playing as White and faced the Lasker-Pelikan variation of the Sicilian.
Things were not really going according to plan, I was down a Knight and facing obliteration. In ...
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What is the idea of 'ponder' in the UCI protocol?
I've created my own chess engine and now I'm trying to connect it into the Chess Arena. Everything is actually working fine when I play them together (Demo). But I tried to play with it and didn't ...
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Null Move Pruning
I just downloaded the latest free version of Komodo 12 to try to disable the Null Move Pruning option. So, in my mind, I supposed that for depth 2, it will need 20*20= 400 nodes However I arrived at ...
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Highest depth ever achieved
I saw a guy that went into depth 70 with no search moves at 41, 192, 897, 168, and 184 nodes from the starting position on Stockfish a few years ago.
I would like to know if this is still a record or ...
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Are there awards or titles for writing chess engines?
I recently found out that, in addition to the well-known titles for chess players, there are titles available for chess composers.
Is there such a thing as an award or title issued to those who have ...
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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 ...
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A question about draw detection in chess engines
Let us look at this position.
[FEN "4k3/8/8/p1p1p1p1/P1P1P1P1/8/8/4K3 w - - 0 1"]
This is obviously a draw. Analyzing this with the Stockfish engine says that it is a balanced position. ...
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limit stockfish 9 to a specific range of ELO rating
I am using stockfish 9 for our chess game project, and I want to limit the ELO rating of the engine to a range. I saw attributes like movetime and depth are used to limit the engine skill level, but I ...
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Looking for a simple GUI for variants of chess
I am currently coding an engine for a variant of chess called Monster Chess. I was wondering if there a GUI existed that would simply take pieces from a square to another (eg e4 to e5) without ...
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Polyglot opening book: getting incorrect moves
I am in the process of adding an opening book to my C++ engine and I hit a problem. Here is what I have:
The Perfect2021.bin opening book that I would like to use.
The function that creates the ...
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Depth problem in stf 12
I don't understand something about depth in STF 12, in fact i thought it was basically the number of anticipated half moves, but when I run it, I sometimes have results with higher depth and less ...
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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 ...
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Chess positions that are easy for humans but near impossible or confusing for computers
I noticed that one student is performing exceptionally well and beyond his level during an online class. I was wondering if there are particular chess positions that I can use during class to find out ...
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How do endgame tablebases calculate checkmates to do retrograde analysis on?
I understand that once endgame tablebases get checkmates, they do retrograde analysis and are able to calculate forced wins. However, how do they calculate the checkmate in the first place? Do they ...
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How can I convert a possible pieces' moves to an actual move in a bitboard?
If I have a bitboard (e.g. for knight squares he can move to) like this:
00000000
00000000
00000000
00000000
00000000
01000000
00100000
N0000000
How can I "convert" it into a move or "...
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Engines tuned to masters’s styles
I saw a stream by IM Eric Rosen where he showed a stronger version of stockfish than the one on lichess.org. He said that it is a version that is given to masters with the evaluation function ...
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How do I find bitboard attack maps non-manually?
I am writing a C++ chess engine based on the magic bitboard, where ordering for bitboards is from LSB to MSB in Little-Endian Rank-File mapping. I'd like to have a 6x64 dimension 2D array for all ...
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Increase in pawn value towards endgames
I’m writing my own chess engine where I’ll be implementing something called a tapered eval which is one that evaluates the position with an endgame specific evaluation function and a middle game ...
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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 ...
user24649
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Can all UCI engines output a FEN for the current position or is it just StockFish?
I know in StockFish if you type "d" you get an ascii view of the board and a FEN string for the current state. Is there any command in other UCI engines such as Rybka 4 that will output a ...
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Why does Stockfish NNUE flatline?
Flatline - to produce a flat evaluation curve.
As I understand engine chess, engines "flatline" in fortress positions. In these positions there are a lot of effectively-equivalent positions ...
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Relation between Elo and search depth for basic minimax
If we use the most basic approach to a chess engine (for example, for a codegolf): minimax to a fixed depth with the material count as static evaluation, then how strong is this algorithm?
This of ...
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How to exercise an opening variation with a chess engine?
I am reading an opening book in King's Gambit, and been writing down the lines to study later. But I wish there was a chess engine, that goes for those lines so I can play against them. I want to play ...
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What do the engine annotations 0.53/24 mean?
I am anaylizing my games with Fritz to get better, but there is an annotation in the analysis that I do not fully understand. Here is an example:
What do 0.53/21 and -0.25/24 mean?
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Stockfish position evaluation component terms in Python?
I saw the excellent Javascript-based guide to how Stockfish evaluates (non-NNUE). Is there a python version out there, perhaps using python-chess?
What I am trying to do (in case you have other ...
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Removing engine thinking (variations) PGN comments in Arena Chess
I setup a position in Arena. Then lets engine vs engine plays it after pressing 'Demo' button.
The problem is Arena put engine thinking as well into the moves list. (in green font). Check the ...
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Can a grandmaster still win against engines if they have a really long consideration time?
Can a grandmaster still win against engines if they have a really long consideration time? For example, say that Stockfish gets 20 minutes and the GM receives days, if not weeks.
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Iterative deepening: what should I do with previous results?
I implemented a negamax with alpha beta and aspiration windows. Now, it also has iterative deepening. When I let the engine run for 15 seconds in the below position, it finds a move at depth 2 with ...
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How do you use Sesse?
How can I set up a position on Sesse? I've been trying to find a way to set up a position on the blank chessboard for half an hour unsuccessfully. How do you do it?
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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 ...
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Did Stockfish regress from October to December 2020? If so, why?
NCM data
If the NCM data is to be believed, somewhere around October 2020, Stockfish dev hit +370 elo vs. Stockfish 7, but has since regressed to only +360. What's going on?
Only thing I can think of ...
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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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Is there a software where we can query historical games to find patterns without inputting the exact chess position?
Suppose one wants to find:
A list of games where White/Black gave each other check more than 10 times.
A list of games where there were Black and White gave each other check in consecutive steps
A ...
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Do Chess Engines hold their Search Tree in Memory?
Does a typical brute-force chess engine (e.g. Stockfish) hold its search tree in memory as it applies iterative deepening? If so how does it avoid running out of space? And if not, how does it store ...
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Obtaining the correct move from syzygy tablebases (Python)
I have created a chess engine in Python and now want to start using the endgame tables in syzygy. I have downloaded all the relevant files and is now ready to start.
I have found how to access the ...
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A historical computer chess endgame
In Season 11 Superfinal Game 78 the following opposite color Bishop endgame was reached:
[FEN "8/2p1k3/1p6/p4B2/P2P1bP1/2P5/1P3K2/8 w - - 0 1"]
In that Superfinal Stockfish smashed Houdini ...
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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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What are the most characteristic signatures if an opponent cheats in online game by using an engine? [duplicate]
Sometimes I feel that a human, particularly a human of about my elo rating, would not ever play so.
I never used an engine in my life for cheating, but I think it is not so hard.
I think, most of the ...
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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 "...
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Why does AlphaZero implement time steps in its input layers?
I'm trying to build my own chess engine using neural nets, and have been researching papers from Deepmind about their algorithm implemented in AlphaZero. Since chess is a game with perfect information ...
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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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