Author: Ralph Stoesser
Date: 16:44:41 07/12/03
Go up one level in this thread
On July 12, 2003 at 14:20:05, Grzegorz Sidorowicz wrote:
>On July 11, 2003 at 09:02:03, Grzegorz Sidorowicz wrote:
>
>[d]8/k7/3p4/p2P1p2/P2P1P2/8/8/K7 w - -
>
>Now my problem is solved!!!
>Problem was in null move but no only in null move.
>I cut off from my program
>
> if (height>=level-2 && wrpx<beta && val_gatunek[spr_poz]==UBOUND)
> {
> do_null=false;
> }
>
>and for example in place where is code:
> case LBOUND:
> if (wrpx>= beta)
> {
> if (antr>1)
> ans_hash[antr].sx=-1;
> return beta;
> }
>
>now I use code:
>
>alpha=max(alpha,wrpx);
>if (alpha>=beta)
>{
> if (antr>1)
> ans_hash[antr].sx=-1;
> return alpha;
>}
>
>and my program can find it on depth after 1 minute on Athlon 1700+
>It is long time but now my program can do it! :-)
>Now I have got next problem. Maybe null move in pown ednings it is bad idea?
>What do you think about it?
>Are you use null move in pown endings?
>Do you think that I can have bug in null move prunning?
>
>Best Regards and thank you gor all!!!
>I love you !!!!
>Now my program can solve 4 position more in WAC!!!!
>wow!
>
>Grzegorz
Null-move in pawn endings is a bad idea, because pawn endings are full of
zugzwang positions. Remember: null-move pruning assumes that, for the side to
move, it's always better to make a move instead of make no move at all. Zugzwang
positions do hurt the precondition of null-move pruning, since zugzwang means:
every move you make worses your position.
-Ralph
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