Computer Chess Club Archives




Subject: Re: Intelligent software, please

Author: Ed Schröder

Date: 10:22:14 11/26/01

Go up one level in this thread

On November 26, 2001 at 08:30:48, Steve Maughan wrote:

>>One recent example: Century 4 eval is more speculative than previous versions.
>>Why? Because I believe (confirmed by my test results) that the program can
>>handle it because of the mixture of smart search and fast hardware. A deep
>>search simply filters out most of the "too speculative errors" of eval and
>>the net result is a better, even more attractive chess engine.
>Interesting.  One similar thing I've got on my to-do list is to look at chnaging
>the size of the positional terms based on search depth.  As an example, suppose
>you have a routine for trapped pieces.  If you detect a trapped or semi trapped
>piece at ply=2 then it would seem silly to give it as big a positional penalty
>as if you found it at ply=15.  In other words if you find it at ply=15 and it is
>significant enough to make it into the PV then it probably is really trapped,
>however if you are at ply=2 there is a real chance that the peice may not be
>trapped at all - hence the evaulation is *really* speculative.  It's easy to see
>this with something like a trapped piece but can one extrapolate it to *all*
>positional terms?  I don't know I haven't tinkered yet.

I never tried the idea to evaluate based on depth so from experience I
can not say the idea is good or bad. The downside of your above idea I
can imagine is that for instance a Nc7xa8 rook capture is rejected at a
15/16 ply depth while it is really needed to take the rook. Thinking on
such devastating side effects make me wonder if it is worthy to put
energy in the idea. Maybe I am wrong, that wouldn't be the first time
considering new idea's.

>One other question - at blitz or bullet chess was the 'Old' Rebel with the extra
>horizon knowledge still the same strength as the 'New' Rebel without the horizon

I haven't tested this as I don't care much at blitz.


>Steve Maughan

This page took 0.03 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.