Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Repitition detection

Author: Gerd Isenberg

Date: 10:13:39 12/28/02

Go up one level in this thread


On December 27, 2002 at 21:03:24, Dan Andersson wrote:

>Ugh! Talk about destroying a nice run time behaviour. Using a 4K hash and a
>rehashing scheme uould get you a mean almost identical to one. The algorithm you
>describe would probably have a mean close to one also, but the standard
>deviation will be horiible to behold. But the missed probe behaviour will be
>real bad. Iterating over the move list raises the cost of an error linearly, or
>very nearly so. Real stupid. There is no excuse whatsoever to use that
>algorithm.
>
>MvH Dan Andersson

Hi Dan,

Thanks for the hint. In some endgame positions i got up to 20% collisions. In
openings or early middlegame < 1%-4%. So about 5% in avarage.

Before i used the even more stupid approach iterating back over the move list,
comparing zobrist keys, first one 4 ply before and then in 2 ply decrements
until there are reversible moves. So the 4KB table was a nice improvement for
me.

But anyway, time to try Bruce's approach.

Regards,
Gerd






This page took 0.01 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.