Questions tagged [engines]

An engine is any machine or computer program that plays chess.

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2
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2answers
114 views

How can I set up en passant in Popeye engine?

I want to solve a problem with Thomas Maeder's excellent Popeye engine, and to specify that a possible en passant in the diagram is ok. How can I do this please? The documentation seems opaque. Thanks ...
25
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3answers
3k views

Is there an engine that finds the best “practical” move?

A standard chess engine will find the move it considers best assuming best play from both sides. But this move might lead to an insignificant advantage or a tricky line that can easily result in ...
3
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2answers
92 views

How does an engine choose between two moves of equal evalulation?

In many positions, different moves are functionally the same, and an engine should return the same evaluation. For example, in a KR vs. KR endgame, (almost) every move that does not lose the rook ...
2
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1answer
137 views

How to tweak a chess engine like SF to return a variation which is only slightly better than your moves?

By default, engines return the strongest variation(s) they calculate. I was wondering if there is a way to tweak an open source chess engine to show a move from their MultiPV which is slightly better ...
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2answers
3k views

Do “chess engine in the cloud” services exist?

And if so, what interfaces can connect to them, and how do they do that? I want to analyze with Lc0, but I don't have a computer with a GPU; I could rent one for a short time period at various cloud ...
17
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4answers
5k views

Creating chess engine, machine learning vs. traditional engine?

I am both an avid chess player and computer programmer. I would say that playing chess and programming are the two things I spend the most time doing. Naturally, I am wanting to create my own engine ...
3
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0answers
51 views

Adding time to game played with chess engine

Are there any chess engines out there that will allow me to add arbitrary amounts of time to their clocks as the game progresses? I am interested in experimenting with two engines playing each other ...
1
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1answer
72 views

What is the most efficient way to calculate attack squares in a chess engine?

I have made a chess engine, and it seems from cProfile that my most expensive function is the one that calculates attack squares for both players. Here is the cProfile results for a perft function I ...
2
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1answer
52 views

Speed of minimax with alpha beta pruning in chess engines

Can a minimax function with just alpha beta pruning really evaluate 1.8 billion chess positions (3 ply = 356) in just a second? My chess engine, which uses minimax with only alpha beta pruning, takes ...
2
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2answers
94 views

What chess app displays the name of the opening being used in the game?

I used to have a chess app that would say the name of the opening being used when you played. Then my tablet broke, and I thought it would be easy to find that chess app, but no luck. Does anyone ...
2
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2answers
199 views

If a pawn promotes to a checking piece while also revealing a check, it is a double check?

I'm writing a chess engine just for fun, and during the validation of movement generation, I found some positions in Perft Results that differ from what my engine is producing. As an example, take ...
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3answers
117 views

Computers and draws

Engines really push for a win in a dead-draw middlegame position, unlike humans who may agree on a draw. Why is that happening?
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4answers
179 views

Are engine ratings directly comparable to human-level play?

Yesterday, I play a game against Stockfish 7, and it has 2200 rating points. I drew 2 games, and lost 1. The point is that if I play against a human-rated 2200 player, I would probably have a ...
1
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1answer
55 views

Software with support for Database with opening analysis

I'm looking for a software tool that will: Engine Support. For analysis suggestions. Support for software evaluation of the moves. I guess this is optional, although I've seen this feature in ...
2
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1answer
143 views

Why can Stockfish give different evaluations at the same depth?

When I let Stockfish get to a certain depth (say depth 33), it gives some evaluation. Then I refresh the position (while leaving Stockfish on) and when it gets to the same depth it gives a different ...
7
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2answers
197 views

First known computer-found error in expert chess analysis

What is the first known example of published expert chess analysis that was disproven by a computer search, with the winning player completely opposite? That is to say, a widely known published ...
4
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1answer
105 views

Chess Engine: Generate a Bitboard of Pinned Pieces

I'm currently working on a chess engine and have a pseudo-legal move generator working. I'm looking for a way to efficiently generate a bitboard of pinned pieces, so I could skip them when generating ...
3
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1answer
114 views

Python-chess : Are the move scores enough to rank moves from the most to least likely moves played by an engine?

My goal is to make a script to finding the most and least likely move an engine will play, and then make a list it. I tried using the scores to make such a list, with the best score equalling the most ...
2
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1answer
192 views

Python-chess : how to get a list for the best engine moves

I am working on a simple cheat detection script to find if a user used one of the top engine moves in a game, so I found this great python-chess library Additionally, I found this example to getting ...
4
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1answer
103 views

Leaving the score aside, what are the criteria allowing Stockfish to choose its “best move”?

I'm trying to understand how a chess engine like Stockfish works. I use Stockfish 10 directly, without an UI. For example, for this position (white to move)... r3n1k1/1bpp2pp/pp2p3/2P1P3/R2P4/3B1rPq/...
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0answers
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SCID vs. PC: Multi-Engine Analysis

Is it possible to configure SCID to output the annotating engine in the variation itself? For example; Ne5 (Stockfish: -0.01 / +0.32 25. Bc4 ...) (Engine2: +0.20 / +0.48 25. 0-0 ...) (Engine3:...
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0answers
105 views

Wrong perft result?

I'm writing a chess engine for fun. Currently I'm finishing writing the move generator. During the research I leaned about PERFT for debugging my software. Indeed, I found many bugs, some of them was "...
3
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1answer
110 views

Stockfish on Android Question

I recently downloaded Stockfish 10 on my android phone and after unzipping the rar file, there were three separate engine binaries and I am wondering which one would be the strongest one to use. The ...
13
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2answers
6k views

Bad Stockfish evaluation

This is the study [fen "3B4/1r2p3/r2p1p2/bkp1P1p1/1p1P1PPp/p1P4P/PPBK4/8 w - - 0 1 "] As you can see, Stockfish gives an absolute decisive win for black, though it is clearly a draw!! Check it out ...
3
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2answers
338 views

How does Allie's search algorithm work?

Allie is a strong engine that's looking competitive with the top ones (Leela Chess Zero and Stockfish). It's supposedly based off AlphaZero, but works differently. As far as I understand it, the most ...
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1answer
75 views

Enable pondering with Leela chess zero

I just got Leela Chess Zero up and running inside docker using this guide. Added a couple of weights from here Now, when I run leela $> lczero -w path/to/weight/file go info depth 16 nodes 435 ...
2
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1answer
109 views

How to use opening books on mac/linux

I would like to use opening books for my stockfish chess engine, but I'm not sure how to do this. As far as I understand stockfish doesn't support these, so I though I setup a system next to stockfish,...
8
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5answers
370 views

Why does Fishtesting test Stockfish against itself, not other engines?

As I understand the so-called Fishtesting, people write patches, then try the patches against the current version of Stockfish. If the new version performs better, it's promoted to be the main version;...
5
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1answer
364 views

Are there any attempts at writing Stockfish MCTS?

As of time of writing, there is one major traditional engine using Monte Carlo Tree Search for its search algorithm - Komodo. The MCTS version of Komodo started out weak but gained strength quickly, ...
5
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2answers
383 views

Leela Chess Zero - UCI engine

What is current use status of Leela for practical player? Is it already working well as UCI? Could anybody give some insight on strength with various thinking times, especially in analysis mode? As ...
3
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3answers
630 views

To what extent (if at all) is the new Komodo 13 MCTS an AlphaZero Lite?

The new Komodo 13 MCTS has been announced with the claim that: Komodo 13 MCTS thinks like no other chess engine in the world. Inspired by the ideas of AlphaZero and Leela, Larry and Mark set out ...
6
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2answers
155 views

How to evaluate and comment moves in PGN format?

I want, with Python-chess, to evaluate any movement of some game and generate the PGN with analysis, as Chess.com does in its analysis. For example, i played one game with fools mate and they ...
0
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1answer
54 views

Is it possible to manually alter initial values in a chess engine?

I am curious of the games that would arise if I changed the initial value of a knight to -1 or make standing on e5 worth -10 points. How would I go about to create such an engine? Is it possible ...
3
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3answers
709 views

Why was castling bad for white in this game, and engine strongly prefered trading queens?

I'm a novice player, trying to improve. In the following game I played as white recently on chess.com, I analysed afterwards and my worst move of the game was apparently when I castled. The engine ...
0
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1answer
84 views

How much of the Principal Variation can I trust? [closed]

Chess engines will have a Principal Variation (PV) that may be as many as 30 (or more) ply deep. Of course, the PV and the other facets of the engine help to determine the best move at the root ...
13
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2answers
745 views

Can an Irwin Cheat Detector catch a user who is using a Leela chess bot for cheating?

I’m a big fan of chess cheat detection apps, like Irwin that was created by lichess.org. But I heard that there is a new bot called Leela that is teaching herself how to play chess, and to think in a ...
2
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2answers
94 views

Is it possible for an engine to be stronger at short time controls, and weaker at long time controls?

Is it possible for engine A to be decisively better than engine B at short time controls (say, 5 min/game) but decisively weaker at long time controls (say, 1 hour/game)? If the answer is yes, what ...
3
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3answers
695 views

Why does Lichess only tell me my “inaccuracies”, “mistakes”, and “blunders”, and not e.g. my “brilliancies”?

A computer analysis of a game in Lichess lists your "inaccuracies", "mistakes", and "blunders". An example is below: What I don't understand is why Lichess doesn't point out my good moves. It seems ...
-2
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1answer
135 views

Why did the (Black) computer play 9. … Ke7 here?

Not having played chess in ~5 years, I started playing against the computer on my phone at ELO~800 (I've since reached ~900). I do not know what engine the app uses (Chess for iPhone by Mastersoft Ltd)...
13
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3answers
2k views

How does engine strength scale with hardware?

Say I run Komodo on my 4-core machine. How much stronger would Komodo be if I used an 8-core machine? A 40-core machine? A 4000-core machine? Is there a general relation for this? Also, does this ...
4
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1answer
97 views

Color-coding moves and games

If you are familiar with watching chess broadcasts on ChessBomb, you'll know they have an engine running on the server which evaluates moves, and colors each move according to whether (according to SF)...
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1answer
228 views

Why does NCM show no progress for Stockfish when each new version has to beat the previous version?

NCM plays each Stockfish dev build 20,000 times against Stockfish 7. This yields an approximate Elo difference and establishes confidence in the strength of the dev builds. As of time of writing, one ...
3
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2answers
175 views

An objective measure of the difference in strength between top programs and top human players in the four most popular forms of chess?

Is there an objective measure of the superiority (or otherwise) that the strongest computer programs enjoy over the strongest human players which can be compared across the four main forms of chess, ...
0
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2answers
175 views

Why is it a mistake to trap this bishop?

In the below position, I played pawn from g7 to g5, trapping the white bishop. The computer didn't like that at all, and gives white a huge advantage. Instead, it wanted me to just simply develop my ...
3
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1answer
97 views

Is there a chess AI that can force checkmate on a specified square?

I'm looking for a program that can force a lone king into checkmate on a specific square. Are there any programs out there that can do this?
5
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3answers
280 views

Do chess AIs still use old-style opening books?

(See also this related question and this related off-site discussion.) Do state-of-the-art chess AIs still normally start games in human-compiled opening books of master games? Years ago, as far as ...
-1
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1answer
166 views

Python and Stockfish [duplicate]

I am trying to get Stockfish to work in Python 3. Just to get started on my project, I tried to have Stockfish think until a depth of 20. However, the program instantly returns that Stockfish ...
10
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3answers
354 views

Human-like engine for endgame training

I am doing endgame training with LucasChess (LC), but the problem is not really related to LC, but to chess engines in general. I have this problem: See picture. When I move Kh6 in this position, ...
5
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2answers
156 views

How do opening books in engine chess work?

I thought opening books were just big compilations of opening moves that engines have access to, and they choose at random which move to play from the list of moves that the opening book says is good. ...
2
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2answers
246 views

Where is the neural network used in MCTS?

Where does an engine (such as AlphaZero) use its neural network in MCTS? It shouldn't be needed to evaluate positions reached via MCTS, since I'm under the impression that only terminal game states ...