Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: a question about redesigning my alphabeta

Author: Dann Corbit

Date: 14:07:36 03/13/04

Go up one level in this thread


On March 13, 2004 at 15:51:12, Uri Blass wrote:

>I redesign my alphabeta and I think to start my alphabeta by trying null move
>because checking for repetition or for hash cut off can be done at the end of
>alpha beta.
>
>When I look at Crafty's code I see that Crafty starts not with null move but
>with checking for repetition and hash.
>
>My question is if there is a soecial reason that I do not understand that Crafty
>does it.
>It seems to me a waste of time to call alphabeta with all the parameters when it
>can be avoided.

Suppose that you have a hash hit.  1/3 of the time it will be true.  Then you
are finished.  Just return the answer.

Suppose that there are lots of repetitions.  Then a check for that will give you
an eval of 0 quickly if there is a repeated position draw.

Repetition count is very cheap.  Hash lookup is very cheap.  Do as little work
as possible.  Crafty is doing it the right way.



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.