Author: Robert Hyatt
Date: 08:52:29 09/20/00
Go up one level in this thread
On September 20, 2000 at 06:36:13, Mike Adams wrote:
> I'm having some trouble realizine the gain ive heard i should from nullmove
>in Pulsar on icc. So i wanted to show you the alorithm that i'm using. its not
>exactly the code my own code is unique to my program and might confuse but its
>essentially the code that i use.
>
>variables:
>endgames: is it endgame 1 or 0
>null: has there been a previous null call
>side: side to move counts up from 1. odd for pulsar even for opponent
>depth: counts down always 0 on first call of qsearch
>beta: could be 10,000 or -10,000 if evaluate hasn't been called
>
>if(endgames==0 && null==1 && side>1 && beta!=10000 && beta!=-10000)
>{
> if(depth-2<=0)
> value=-qsearch(-beta, -alpha, 0, (side+1), myenpassant);
> else
>{ /* you can ignore the hash it just changes side to move and
> I only use hashing for move ordering anyway so shouldnt have big impact
>*/
> passhash=computecurrenthash(currenthash, 0, 0,0, 1);
> value=-search(-beta, -alpha, depth-2, (side+1), myenpassant, passhash);
>}
> if(value>=beta)
> return beta;
>
>}
You appear to be using R=1 for your null-move search. IE where you call
search/quiesce with depth-1 normally, you are using depth-2. Most of us are
using R=2 which means depth-3 rather than depth-2. Some of us even use a
dynamic R that varies from 2 to 3, which means from depth-3 to depth-4
depending. That will make a big difference.
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