All Questions

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

What is the highest mobility score of a board without a checkmate, stalemate, or draw?

I consider the mobility score of a board to be the number of legal moves one player could make less the number of legal moves the other player could make. 8/7k/2Q2K2/8/6b1/8/8/8 w - - 0 1 Using the ...
5
votes
4answers
881 views

Help with game phase identification

I'm working on a chess AI for a school project and I am looking into ways to identify the current phase of a board, meaning the opening, middlegame, and endgame. I have seen an article explaining ...
1
vote
1answer
71 views

Can engines use the current pawn structure to refine its search/eval?

As I understand it, engines use so-called "bitboards" to generate the current position & possible moves. I'm wondering if any engine uses the pawn bitboard to refine its search and eval. To ...
3
votes
2answers
121 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 ...
4
votes
1answer
136 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)...
5
votes
1answer
882 views

Oscillating Stockfish Evaluation on Laptop

I'm using stockfish-9-bmi2 on my laptop to provide me move by move evaluation of games. I've set Stockfish to evaluate to depth = 25 plys. I find that the evaluation provided oscillates move-on-move ...
0
votes
1answer
106 views

Decent Playing Strength Chess Engine

I'd like to make a chess program to play decent strength chess (say around 2100 ELO). What are the factors in Eval & techniques in Search that one would consider to achieve that rating?
4
votes
1answer
229 views

How are chess engines able to rank a Mate in X above a Mate in X+Y?

According to an engine, a mate in X moves = +infinity, since it is a forced win for it. Also according to an engine, a mate in X+Y moves = +infinity, since it's a forced win (just more moves, but an ...
0
votes
1answer
121 views

Is there a way to get MANY and FAST (but not deep) position evaluations in javascript?

I am working on a statistical chess project that needs to evaluate many (about 20-30) different positions per turn. They do not need to be deep but fast. Is there a possibility to use engines (...
3
votes
1answer
176 views

What kind of hand-crafted features do top performing family of engines use to evaluate a position?

AlphaZero paper which introduced the engine which allegidly outperformed stockfish mentioned the following: These programs evaluate positions using features handcrafted by human grandmasters and ...
7
votes
2answers
519 views

How do chess engines evaluate a position if the position is in the middle of an exchange?

In the minimax algorithm, chess engines do a depth-first search as far as they can calculate ahead, and then evaluate all these final positions. Then, using these evaluations they work backwards one ...
3
votes
3answers
666 views

Engine evaluating changing after making move suggested by engine

I've noticed that the engine (Stockfish 9) evaluates positions as significantly better for white if the evaluation is performed while white is on the move. The difference is sometimes more than half a ...
1
vote
4answers
337 views

In engines vs engine game, both think “optimistically”: that they are in better shape than what their opponent thinks the evaluation score is

I observed in many Tcec games of season 10 (and possibly repeats trough seasons) that white evaluation score of a position is always greater (not in terms of absolute value, but in terms of the ">" ...
3
votes
2answers
355 views

How to write a simple chess engine to statically evaluate a position?

I want to evaluate positions statically. So I've written a code which evaluates from a FEN string. However it is a tedious to copy FEN and then paste for a complete game. So I wanted to know if it ...
3
votes
2answers
2k views

How to write a chess evaluation function?

I don't know very much about chess beyond the rules but I enjoy programming and am trying to write a chess engine. I recently found this evaluation function: Simple Evaluation Function. What would be ...
2
votes
2answers
225 views

Engine evaluation in endgame not increasing, what it means?

I have plenty of endgames that engine evaluates like +1, even +2, not changing much for like 50-100 halfmoves, repeating, playing without plan. Defending side seems to be always just in time on right ...
4
votes
1answer
650 views

Does engine score correlate with winning chances?

I was wondering if there is a statistical or probabilistic (at least approximate) way of looking at a score of a chess position of a certain fixed engine, say "crafty version 5" for example. i.e. ...
7
votes
2answers
1k views

Is there an online chess evaluation engine with a REST API?

Is there an online chess evaluation engine with a REST API? I'd like to be able to send a game or position (with castling ability presumably) to a simple REST API and get back the positional ...
1
vote
1answer
666 views

Database of analysed positions with corresponding scores

I am looking for a database with many various chess positions with a corresponding engine score. Something like (position, score): 6r1/3k4/4b1rB/p2p1R2/1pp5/8/PP5Q/7K w - - 1 39 1.25 rn2nrk1/...
0
votes
1answer
786 views

When evaluating score of new position with UCI chess engine is the Hash used at all?

I am using a UCI chess engine (stockfish 6) to evaluate the score of specific positions from different games. On this stockfish help forum thread it states: Hash size is the amount of memory you want ...
2
votes
1answer
302 views

Extracting features from chessboard

So i am implementing an intelligent chess agent with the use of reinforcement learning.I intend to use Java. After reading the master thesis of H.Mannen i decided to use some of the features listed ...
0
votes
1answer
92 views

Continuous evaluation of engine in ChessBase

I just bought ChessBase 13 and downloaded Stockfish, but when I am analyzing my games there is no continuous evaluation of the moves. So say I make 3 extra moves, the engine is still calculating the ...
12
votes
1answer
2k views

Why does Fritz prefer underpromotion in this position?

Why does Fritz prefer underpromotion in this position? How can underpromotion to bishop evaluate so much higher than normal queen promotion? Can this be a bug in the Fritz 14 chess engine?
9
votes
8answers
3k views

Bishop vs Knight

I read in a book written by Fischer about piece values, and he said that a knight is worth 3 pawns, and a bishop is worth 3,25 pawns. I know that in closed positions knights are better, and I have ...
1
vote
1answer
846 views

Matrix representation of piece position for a chess engine

Looking into a source code of a chess engine, I noticed matrices that represent position of some pieces. knightPos = [ -200, -100, -50, -50, -50, -50, -100, -200, -100, 0, 0, 0, 0, 0, 0, -100, ...
4
votes
2answers
483 views

how to evaluate the position inside the search function

using PVS Algorithm with Quiet search and zero window search what should the range of the score be (-infinity, infinity ) could it be as small as (-16000,16000) and what should the search return if it'...
2
votes
2answers
2k views

UCI engine state notion

Hi guys I have a problem with using stockfish engine which is using UCI protocol. I wanted to play black and the computer white. But so far I think that uci engine has no notion of state and it gives ...
2
votes
1answer
415 views

Stop SF MultiPV from returning an upperbound

For a given position, I'd like to compute an evaluation of the 3 best moves. I send this to Stockfish: setoption name MultiPV value 3 position startpos go movetime 500.0 // search for 0.5 seconds I ...
2
votes
3answers
2k views

How to evaluate my move with UCI engine?

I am looking for a way to analyse the moves I play. I'm NOT looking for a suggestion of a GUI that does this, or using Chessbase to do this. I want to know how to do this by communicating directly ...
2
votes
1answer
1k views

What are the scales of the numerical evaluations of the strongest engines based on?

Different engines have different scales for their numerical evaluations (for example, Houdini's evaluations are usually much lower than Stockfish's evaluations). This is because different engines use ...
4
votes
4answers
982 views

What relative point values of pieces do engines use?

Humans use: Pawn = 1 Knight = 3 Bishop = 3 Rook = 5 Queen = 9.5 Bishop pair = +0.5 But I would like to know what relative point values do engines use (preferably strong engines, like Stockfish, ...
1
vote
1answer
441 views

Is my engine working properly?

I noticed that when I put my Houdini 3 Pro x64 in the "Infinite Analysis" mode, he tends to use a lot of time to evaluate the bad moves... Sometimes he even uses like 30 seconds on the first 10 best ...
4
votes
5answers
1k views

What are the first moves chosen (White), by brute force chess engines?

Title says it all. Feel free to add comment, theory, or explanation. Just to clarify, this is only regarding turn 1 of White, and no proceeding turns after it.
17
votes
4answers
3k views

Why do chess engines sometimes miss good moves (or take forever to spot)?

It is not the first time that I found a greatly superior move than the chess engine did, it even takes them a while to understand these moves after you make them. For example, the move 15 ... Bf2 in ...
14
votes
3answers
3k views

Computer evaluations: How trustworthy are they?

Fritz 12 with Rybka gave a friend of mine an evaluation of +3 for white in this endgame position, [Title "White to move"] [FEN "8/8/8/3k3p/3P3K/2P3R1/8/7r w - - 0 1"] which turned out to be a draw. ...
8
votes
1answer
289 views

Elements to take into account when evaluating 'board strength'

As part of a demo for a rules engine I'm dreaming up, I'd like to do an evaluation of a chess board that communicates each side's general strength at that point in time. Advanced things like ...
12
votes
8answers
13k views

What is an accurate way to evaluate chess positions?

I've been interested for a while about a computer chess AI algorithms (and got the chance to work on one at some point) like Minimax, and as the core component of these algorithms is the so-called ...