Author: Richard Pijl
Date: 07:43:45 09/03/04
Go up one level in this thread
On September 03, 2004 at 10:14:53, Stuart Cracraft wrote:
>On September 03, 2004 at 09:47:26, Jan K. wrote:
>
>>You should look for bugs in your search....i find the move even with no
>>extensions but the threat extension set to 1/2 ply and no checks in qsearch.
>>Takes 60 seconds and almost the same number of nodes like your full search.
>
>Tord said something about having the null move search a window
>wider than -beta+1,beta and and then testing the return value
>against alpha-MARGIN. If less than that, a faillow and then
>extending.
>
>Has anyone else with PVS search implemented mate. Can you just
>include your code fragment in reply to this. I have programmer's
>block.
>
>Thanks. Stuart
The code below seems to work ok. The Baron (without giving checks in qsearch,
and recapture extensions) finds WAC141 in less than 10 seconds on a Xeon 2.8.
makenull();
/* do reduced search */
if (depth-R < ONEPLY) {
x=-quiesce(-tbeta, -tbeta+1);
} else {
x=-search(-tbeta, -tbeta+1, depth-R, total_ext);
}
takeback();
if ((x >= tbeta) && (x<30000)) {
/* Good score, but do not cutoff with a matescore to prevent zugzwang
issues */
return x;
}
if (x<=-30000) {
/* Opponent has matethreat */
ext+=THREAT_EXTENSION;
}
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.