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Subject: null move improvement ?

Author: Klaus Friedel

Date: 03:17:15 03/31/02

Has anybody ever tried something like that in his null move code :


	int nullDepth = depth - (NULL_REDUCE + 1)*DEPTH_BASE;

	if(tryNull){
		executeNullMove();
		beta -= NULL_BONUS;
		value = - search(nullDepth, -beta, -beta+1, ply + 1);
		undoNullMove();
		if(value >= beta){
			beta += NULL_BONUS;
			ttStore();
			return beta;
		}
		beta += NULL_BONUS;
	}


Bigger values of NULL_BONUS increase the count of nodes prunded (but you migth
oversee some tactics). Values of about 30cp made my engine ply slightly better
than the default null-move (NULL_BONUS = 0).


Klaus

• Re: null move improvement ? Ulrich Tuerke 06:53:44 03/31/02
• Re: null move improvement ? José Carlos 04:10:41 03/31/02
  • Re: null move improvement ? Uri Blass 04:22:25 03/31/02
    • Re: null move improvement ? José Carlos 08:09:57 03/31/02
    • Re: null move improvement ? Klaus Friedel 05:40:26 03/31/02
      • Re: null move improvement ? José Carlos 08:01:46 03/31/02
      • Re: null move improvement ? Uri Blass 05:50:35 03/31/02
    • Re: null move improvement ? Andrew Williams 04:31:36 03/31/02
      • Re: null move improvement ? (error in my previous post) Andrew Williams 08:44:15 03/31/02
• Re: null move improvement ? Gian-Carlo Pascutto 03:29:43 03/31/02
  • Re: null move improvement ? Klaus Friedel 05:55:54 03/31/02
    • Re: null move improvement ? Gian-Carlo Pascutto 07:06:16 03/31/02
      • Re: null move improvement ? Christophe Theron 08:09:53 03/31/02
  • Re: null move improvement ? Sune Fischer 05:26:41 03/31/02
    • Re: null move improvement ? Gian-Carlo Pascutto 07:01:40 03/31/02
  • Re: null move improvement ? Uri Blass 04:38:58 03/31/02

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