I just wanted to learn name of algorithms.. thanks
A:
If you need an in-depth knowledge about AI algorithms, I think "artificial intelligence modern approach" book is the best source.
Upul
2010-01-08 08:21:42
That would be *one* part of a chess playing algorithm. However, minimax is not a chess algorithm in itself.
Tarydon
2010-01-08 08:22:58
I agree Wikipedia is a good place to look but Rybka is closed source so probably not much help
Dave Webb
2010-01-08 08:29:45
@Dave: True, but it solves anarhikos problem of *just wanting to learn name of algorithms*.
Tarydon
2010-01-08 08:51:20
@Tarydon - Rybka is the name of a _chess engine_. As it's closed source no-one (apart from the author) knows which algorithms it uses.
Dave Webb
2010-01-08 10:38:57
@Dave: You win. I concede :) I can't downvote my own answer, so could you please do that?
Tarydon
2010-01-08 11:15:09
@Tarydon - It's a good answer; Wikipedia will be an invaluable resource here. Just edit it and replace Rybka with an algorithm.
Dave Webb
2010-01-08 13:40:40
+4
A:
A general strategy in game algorithms is the minimax strategy, augmented with alpha-beta pruning. The minimax algorithm finds the best move, and alpha-beta pruning prevents it from going into branches of the game tree that cannot produce a better result than previous branches already have.
However, the chess game tree is too large to be completely examined. That is why computer chess engines only examine the tree up to a certain depth, and then use various methods to evaluate the positions. Many of these methods are based on heuristics. Also, a serious chess-playing program will have a library of openings so that it can play in the beginning by just consulting that library and not having to examine the game tree. Finally, many end games are completely solved, and these are also programmed in as a library.
jk
2010-01-08 08:34:34
An equivalent of minimax is called negamax. The difference is that the score is negated at each change of depth in the tree. This way both players are trying to maximize the score (where in minimax one is trying to minimize it). I'm not sure what this does to the alpha/beta window. Does it become just a single value?
phkahler
2010-01-08 19:07:07
it should be noted that the position evaluation function is probably the single most important aspect of a chess engine when determining its strength.In fact, its probably the only area where there is novelty in most chess engines now adays. For example, the Rybka position evaluation function was designed over 5 years (if irc) by very strong players. In a sense the evaluation function is what gives the computer intuition about the chess position, a fundamentally important part of any chess game and orthogonal to other issues like tactics in the game.
ldog
2010-01-09 21:05:08
@gmatt - only partially true... aggressive pruning is part of what makes Rybka so strong, and the research in that isn't too old. Extended futility pruning, limited razoring, and adaptive null move pruning were state of the art less than a decade ago
tbischel
2010-06-22 21:31:58
A:
Have a look at the some of the free source chess codes, for instance Crafty or even better how about Fruit? It plays pretty much almost the same strength of Rybka. But there are many new algos out there. Day will come when human chess players will have to just say I am not playing vs this engine, and this article pretty much sums it up --> http://www.mychessblog.com/man-versus-machine-when-a-computer-will-become-world-chess-champion/
chessplayer
2010-01-08 23:54:33
A:
Lots of algorithms that are used within chess programming are described on http://chessprogramming.wikispaces.com/ website. There are several open source programs available that are implementing these algorithms.
JanK
2010-01-11 08:54:08