New answers tagged engines
0
I'm very late but I am working on something similar. Here are are a couple of resources that involve using autoencoders.
https://chessvschessproject.wordpress.com/
https://arxiv.org/abs/1711.09667
https://github.com/oripress/DeepChess
Hope they help! Let me know how it goes.
1
The computer is a calculator. It does not think but just calculates. As a result, it is very good at tactics, seeing deeper as the level is increased. I've been playing the computer exclusively for the past 8 months or so, generally at a medium setting to have a better chance to make a combination against it. I find that it does help sharpen my tactics, ...
5
One way to fool some computers is to give them a fortress and then
offer material to trick them into opening the portcullis. For example:
[Title "White to draw"]
[FEN "8/8/pr1k4/Pp2rp1p/1Pp1pPpP/2PpP1P1/3P4/3K4 w - - 0 0"]
1. fxe5+?? (1. Ke1) (1. Kc1) 1... Kxe5 2. axb6 Kd6 0-1
Many computers won't resist the temptation to win RR for ...
4
Yes, endgame tablebases are calculated by brute force. That's why we only have complete 7-men tablebases today (which were published in 2012).
When stockfish finds a mate with more pieces than stockfish has calculated until only 7 men are on the board and the tablebases give stockfish the solution for the rest.
2
Roughly, yes. To build a tablebase for a certain material combination you will want to have every legal configuration of those pieces in memory. (in practice one can optimize that a bit) Then you check which of the positions are already checkmate. And yes, then you work backwards and find longer and longer wins. (and then all remaining positions that aren't ...
2
There are actually two questions in your post
How to convert Attacks in Bitboards to a list of moves?
How to represent those moves?
How to represent those moves?
This question has been discussed here and here thoroughly. But to provide some context to the readers of this post, a very simple way to do this can be to use a class / struct to represent a ...
1
There are many elements that a computer looks at to determine how the computer plays. A more defensive computer would place more value on the pawns around the king. A more attacking computer would place more value on retaining pieces, to maintain the attacking possibilities. The choice of opening and the central pawn structure affects the overall playing ...
0
Stockfish (https://stockfishchess.org/download/) is open source and uses magic bitboards.
Crafty (https://craftychess.com/) uses bitboards and is heavily commented.
There are other using bitboards, but these two are the best.
Hopefully this helps.
3
I've tried programming with the relative values of pieces changing with relation to material. I've found that a maximum value of 110 centipawns*, without bonuses, was a fair value. (FYI, the knight's value decreases as material is reduced, so this dynamic adjustment of value decreases for the knight.)
A square value, where the pawn gets a bonus the farther ...
2
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?
Not very strong.
Even though the material value is a significant factor in evaluation. There are many more factors that you need to consider to build a strong evaluation ...
4
From reading various chess source codes, mostly before 2005, I can state that most don't a FEN output. Any that would allow for a non-starting position should accept FEN, as it's just a special form of PGN.
Crafty and san_kit both have a "fen" command.
1
I am rated 1410 USCF. I played all 8 Stockfish levels this past weekend, once with each color. My record was 11-5.
I was 2-0 vs Stockfish 1-5, 1-1 vs Stockfish 6, and 0-2 vs Stockfish 7 and 8.
3
Chess engines use an opening book during the opening. The standard way of doing what you ask is to build your own opening book and point the chess engine to that so it uses your book and not the previously supplied one.
When you are done just switch back.
1
Just set up the position you're interested in using Forsyth–Edwards Notation
and feed it to the engine. For example if you want the engine to play the Muzio Gambit, give it this FEN: rnbqkbnr/pppp1p1p/8/8/2B1Ppp1/5N2/PPPP2PP/RNBQ1RK1 b kq - 1 5
Which corresponds to this position with Black to play:
rnbqkbnr/pppp1p1p/8/8/2B1Ppp1/5N2/PPPP2PP/RNBQ1RK1 b kq - 1 ...
5
The score 0.53/21 means the chess engine evaluates the position after 6... Ng8-f6 at 0.53 pawns (or 53 centipawns) in White's favour after completing a search depth of 21 ply (or half-moves). It means White has a slight advantage.
Similarly -0.25/24 means the engine evaluates the position after 6... e7-e6 as 0.25 pawns (or 25 centipawns) in Black's favour ...
1
Go to Options → Appearance → Movelist and under View uncheck "Show comments in the movelist". This should hide the engine thinking variations.
Alternatively, you can right-click in a move → Display → Comments.
2
The computer's big advantage is its speed. It can look at millions of possibilities in seconds. But the human Grandmaster would have the advantage of being more selective and knowing just what variations to concentrate on. Based upon that, I would think that given unlimited time, a Grandmaster would be able to defeat the machine under the conditions you ...
1
Stockfish stopped using opening books a long time ago. That is, it's an engine, and if you want to use an opening book, you have to use it in UI that you use to play the game or in the software you use to interface with the engine, playing book moves without even telling Stockfish about that.
There's no way to tell Stockfish about existing books (the ...
14
Here's a comment by GM Kaufman, developer of Komodo (emphasis mine).
Q: Author Cyrus Lakdawala suggested I ask: In what respect are the program's move choices human?
A: All the features of the engines' evaluation function have been based on how some human (in the case of Komodo, me) thinks they should be defined. The weights were originally my subjective ...
18
Are there asymmetric time controls where a GM can still beat Stockfish? Certainly, as long as you give Stockfish little enough time. I think the time you give to Stockfish is almost more important than the time that the GM gets. At 20ms I would favor the GM even at tournament time controls.
A few years back I played a handicap game against Komodo where I ...
2
In alpha/beta pruning, the order that moves are searched in matters a great deal. You always want the best move(s) to be searched first--this creates more beta cutoffs. The basic idea is that before searching each level of the tree, we will sort the moves based on how good they are, then search the moves in that order.
Of course, this is quasi-paradoxical (&...
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