Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Another question...

Author: Robert Hyatt

Date: 06:06:40 08/02/99

Go up one level in this thread


On August 02, 1999 at 04:34:03, Scott Gasch wrote:

>Sorry for flooding the board with my questions... :)
>
>I have another one.  I am running into slow middle game performance because of
>high numbers of captures and deep qeval extensions.  What are some of the ways
>people are using to limit the number of captures considered by qeval?  Is there
>an easy way to throw out captures that don't make any sense in order to speed up
>the program?
>
>Thanks,
>Scott


I use a static exchange evaluator to purge captures (in the q-search only)
that seem to lose material (ie QxN, PxQ).  You can also do alpha-based
pruning...  if the current material score is way below alpha, and you are
sure your positional score can't pull the score up to alpha, and a capture
can't do so either, then the capture can be ignored.  IE material_score ==
-500 (rook down), alpha=100.  You know your largest positional score is +300,
and you are considering a move like NxP.  material+300+100 is < alpha.  No
sense in searching that NxP.



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.