Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Avoid perpetual check?

Author: Ed Schröder

Date: 12:28:06 09/05/04

Go up one level in this thread


On September 05, 2004 at 11:16:31, Uri Blass wrote:

>On September 05, 2004 at 11:02:17, Ed Schröder wrote:
>
>>On September 04, 2004 at 17:22:40, Uri Blass wrote:
>>
>>>On September 04, 2004 at 17:06:50, Chris Welty wrote:
>>>
>>>>On September 04, 2004 at 17:01:40, Uri Blass wrote:
>>>>
>>>>>Movei does not use hash for pruning.
>>>>>
>>>>>Uri
>>>>
>>>>Interesting. Why not?
>>>
>>>I believe that using hash for pruning limit my possibiloities for improvement
>>>with evaluation that is not dependent only on the leaf position and at this time
>>>there are more important things to do then using hash for pruning.
>>
>>Excuse my ignorance but what is hash pruning?
>>
>>My best,
>>
>>Ed

>It is what almost every program is using.

I am pretty sure you are one of the only.


>It is returning value based on hash tables because the position was already
>searched in the past with bigger or equal depth.
>
>Movei is not using it and it is using hash tables only for order of moves and I
>believe that it enable more possibilities for evaluation that is not based only
>on the leaf position(for example movei can detect a lot of perpetual checks
>without seeing the draw because it's evaluation suspect the draw after a lot of
>checks so it gets closer to 0 when other programs cannot do it.

>Of course detecting perpetual check faster is not the only idea that it can be
>used for.

Last time I checked hash-pruning is good for speedup factor of 2-3 in the
midgame and much much more in the endgame. I think you should reconsider.

My best,

Ed



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.