Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Verified Null-Move Pruning, ICGA 25(3)

Author: Vincent Diepeveen

Date: 19:17:01 11/21/02

Go up one level in this thread


On November 21, 2002 at 22:15:39, Uri Blass wrote:

it is here too Uri.

>On November 21, 2002 at 22:05:15, Vincent Diepeveen wrote:
>
>>On November 21, 2002 at 11:14:24, Robert Hyatt wrote:
>>
>>Just go for a 2 minute single cpu implementation.
>>
>>But of course you will find that R=2 always will outperform
>>already his verification search with 1 ply reduction.
>>
>>You can implement it quicker his algorithm by doing next
>>after nullmove:
>>
>>int Search(alfa,beta,depthleft,allowingnull) {
>>  ..
>>
>>  if( !allowingnull && nullmoveok ) {
>>    .. try nullmove
>>    if( score >= beta ) { // score returned by nullmove
>>      score = Search(alfa,beta,depthleft-1,true);
>>       // last parameter to prevent another reduction next position
>>      if( score >= beta ) {
>>        StoreInHashtableAndKillerTable(..);
>>        return score;
>>      }
>>    }
>>  }
>>  ..
>>
>>This is a more elegant way to implement it, and it was already done
>>years ago and published in ICCA journal.
>
>
>No
>
>It is not his algorithm.
>The verify parameter in his article is not allowingnull.
>
>It is a parameter that tells the computer if to allow searching to depth-1 in
>the subtree.
>
>Uri



This page took 0.11 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.