Author: Omid David Tabibi
Date: 13:01:23 04/01/04
Go up one level in this thread
On April 01, 2004 at 15:46:19, Steve Maughan wrote:
>All,
>
>When doing an ordinary null move (R=2) what depth reduction should actually be
>used? Two possibilities:
>
>a) Depth Next Ply = Current Depth - 2
>
>b) Depth Next Ply = (Current Depth - 1) - 2
>
>i.e. does the (R=2) refer to a depth reduction of 2 or an *additional* depth
>reduction of 2?
/* the depth reduction factor */
#define R 2
int search (alpha, beta, depth) {
if (depth <= 0)
return evaluate(); /* in practice, quiescence() is called here */
/* conduct a null-move search if it is legal and desired */
if (!in_check() && null_ok()) {
make_null_move();
/* null-move search with minimal window around beta */
value = -search(-beta, -beta + 1, depth - R - 1);
if (value >= beta) /* cutoff in case of fail-high */
return value;
}
/* continue regular NegaScout/PVS search */
. . .
}
Figure 1: Standard null-move pruning.
>
>Thanks,
>
>Steve
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.