info-gnu-chess
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Searching simple opensource chess program


From: -nospam-
Subject: Re: Searching simple opensource chess program
Date: Sun, 19 Dec 2004 19:22:32 GMT
User-agent: Mozilla/5.0 (Macintosh; U; PPC Mac OS X Mach-O; en-US; rv:1.7.3) Gecko/20040910

Paul Pichota wrote:

For a university project I want to compare different algorithms (minimax, alpha-beta and some variants). So I am looking for rather simple and working opensource program where I can easily exchange the algorithms.

I have tried the same stuff but I came to following conclusion: In order to evaluate an algorithm you have to cross-check the results with the results obtained from a brute-force search. The brute-force attack must come to a position where the score is agreed with all parties involved.

This has 3 major drawbacks.

1) Brute force search in chess is very time consuming. Move generation is complex and takes a lot of time if a large tree is to be searched. (e.g. if you try the go game, you will understand where the compexity lies.) 2) A definite chess score is obtained in the same chess program in the evaluation function. When comparing the chess score obtained with other chess programs or a human evaluation, scores may vary. Only mate and technical draw positions are definite. 3) Before all rules (ep, 50moves, 3 fold-repetition) are implemented, it takes a lot of time and effort. Effort that does not contribute to the algorithm development.

So in order to compare different algorithms, I designed a program with different algorithms and different games. The only thing you have to do is to select the algorithm, and the game-ruleset. Because of the complexity of a chess program, it is left out however. But I did include checkers, connect 4, tictactoe, draughts, othello/reversi... etc. I also implemented different algorithms and you can ask for a move to be generated with all algorithms in parallel. You can easily compare the output from minimax/brute-force/alpha-beta/negascout. It is called strategicgames.

> I have already tried GNU Chess but the search routine is rather
> complex because of various prunings, heuristics etc.

I can send you the source of my chess program named 'Belofte'. I can assure you, it is much simpler than gnuchess. You can test playing against it on freechess.org. Finger belofte for more details. Mail me for getting the source code. www.internetcontact.be/~macchess

You can also download the source code of the strategic games. It can be downloaded from users.telenet.be/artificialintelligence.

PS: Strategic Games does have some errors in the negascout and the move-generation for some checkers variants.... Feel free to correct.

Good luck,

Yves


reply via email to

[Prev in Thread] Current Thread [Next in Thread]