Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Local optima / genetic algorithms

Author: Pat King

Date: 23:19:07 08/03/98

Go up one level in this thread



On August 03, 1998 at 16:57:04, James Long wrote:

>As I rewrite my program, I've been seriously considering
>trying a genetic algorithm to train the evaluation
>function.  I've got a pretty good grasp on how to
>handle this, but a couple of things are still
>bothering me:
>
>Most programmers hand tune their eval functions, either
>themselves or with the help of a strong player.  Is
>this because the results are generally better, or
>because a good learning eval is difficult to write?

The learning part isn't difficult. I had a GA tuning v2.0 of
my program several years ago. The problem is that the
learning is SLOW! This was compounded in my case by
a pretty doggy chess engine. Now that I've V4.0 almost
running, I may give it another try.

>For the program to "learn," the eval variables must
>mutate dependent on the outcome of a game.  One approach
>I read about is to set up a tournament of 100 "players,"
>each player having random values assigned to its
>eval terms (with the exception of the pawn score).

I strongly suggest getting in the ballpark first with some
manual tuning, even if you're a lousy chessplayer.

Good Luck!

Pat



This page took 0 seconds to execute

Last modified: Thu, 15 Apr 21 08:11:13 -0700

Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.