Computer Chess Club Archives




Subject: Re: Deep Search Extension

Author: Ernst A. Heinz

Date: 06:01:59 01/22/98

Go up one level in this thread

On January 22, 1998 at 08:42:06, Robert Hyatt wrote:

>Yep... Forgot.  For me, I couldn't do the above... because I don't use
>fail-soft and most scores (excepting mate and draw) are always inside
>the alpha/beta window.  But shifting the null-move window down does
>exactly the same thing, ie searching alpha-piece, beta-piece produces
>the same information.

Yes, but it is much more expensive because you must do a second null
move search whose trans/ref efficiency is probably bad because of the
shifted search bounds. Furthermore, the condition of the static
evaluation failing high is important.

>I thought my idea of first noting that this was a PV move, and then
>trying the null-move threat extension only after that was from the

As you can only do a non-zero window null move search somewhere down
the PV, this is certainly implied by the paper.


This page took 0.04 seconds to execute

Last modified: Thu, 07 Jul 11 08:48:38 -0700

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