Questions tagged [engines]

Questions relating to chess engines: any computer program that is able to play/analyze chess positions.

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1answer
48 views

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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0answers
48 views

Unity variables disappear when a method is called on an event from an external process [closed]

I'm writing a chess UI with Unity as well as an external engine (executable written in c#). I can send and receive data to and from the process (engine). This is working, But when the Make_Move method ...
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0answers
100 views

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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1answer
66 views

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 ...
2
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1answer
83 views
+100

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 ...
4
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1answer
118 views

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. ...
2
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1answer
48 views

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 ...
0
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1answer
41 views

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 ...
1
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1answer
35 views

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 ...
1
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1answer
39 views

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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0answers
98 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 ...
12
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3answers
671 views

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 ...
2
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2answers
117 views

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 ...
3
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1answer
84 views

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 "...
3
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1answer
77 views

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 ...
1
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1answer
43 views

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 ...
5
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1answer
80 views

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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3answers
164 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 ...
3
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1answer
211 views

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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0answers
82 views

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 ...
3
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1answer
109 views

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 ...
6
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2answers
189 views

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 ...
3
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1answer
74 views

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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0answers
16 views

How to convert commentary into variation in Arena chess?

After analyzing a game by Arena, I got the following output. The moves in the green font are engine suggestion/variation. The problem is I cannot click on moves (in green color). It is put as a ...
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0answers
78 views

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 ...
5
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1answer
54 views

Removing engine thinking (variations) 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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3answers
3k views

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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1answer
75 views

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 ...
3
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2answers
220 views

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?
3
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1answer
155 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 ...
13
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1answer
4k views

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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0answers
87 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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2answers
97 views

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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2answers
208 views

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 ...
4
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1answer
141 views

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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1answer
92 views

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 ...
8
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3answers
508 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 ...
1
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1answer
127 views

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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2answers
159 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 "...
3
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1answer
139 views

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 ...
4
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2answers
189 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 ...
2
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1answer
341 views

How should I configure Stockfish if I want it to play as a 2800 ELO player without the UCI_LimitStrength value?

Stockfish has so many parameters that I'm not sure which one I should change so that it has a strength equivalent to that of a human who has 2800 ELO, well that's one of my wishes, the other is to be ...
3
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2answers
241 views

NNUE Based Engines - Post Move Analysis

Its a bit of a wordy question as there is a lot of background to provide context for thinking and analysis so for that I apologise you can skip the background if you want but it might provide some ...
3
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1answer
164 views

Candidates for the longest 8 man checkmates?

Are there proven 8 men checkmates that have a good chance to be the longest checkmates? How were they proven and why are they good candidates?
21
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5answers
9k views

What prevents chess engines from being undetectable?

I see accounts of people getting banned from sites like chess.com for using engines like Stockfish and Komodo (I admit I have used these engines before, but never in an actual match). Now, I believe ...
8
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4answers
2k views

Why does this puzzle offer f8=R as better than f8=Q?

Here's a chess puzzle that gave a confusing response. https://chesspuzzle.net/Puzzle/52112 [FEN "5R2/1p6/p4Ppk/3r4/7p/1P6/P7/1K6 w - - 0 1"] 1. Rh8+ Kg5 2. f7 Rf5 3. f8=R If you play f8=Q ...
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4answers
338 views

The chess.com vs computer games celebrity category

I came upon chess.com playing against computer mode. I found a resemblance of two professional chess players over there. Do they really resemble their gameplay, though? Does the AI mimic their past ...
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2answers
105 views

Is it preferable to pass a FEN notation or list of moves to a chess engine?

I am actually programming a chess UI and I'd like to communicate with a chess engine using UCI protocol. After reading the protocol specifications, I am not sure how to use the position command. For ...
6
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1answer
2k views

Could a top ranked GM draw against Stockfish using drawish opening lines in classical chess?

We know that are many lines which White can choose which are very drawish at 2700+ level. Drawing is easy to a very good chess player such as Carlsen, who knows dozens of forced draw lines. When I say ...
2
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1answer
133 views

The most efficient valid move generation for minimax

Problem I am creating a chess engine in Python using Minimax algorithm (with alpha/beta pruning) but I have some issues with performance. Currently the thinking time looks something like this for a ...

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