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Subject: Re: Limit extensions

Author: Angrim

Date: 15:28:09 07/06/04

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On July 06, 2004 at 12:30:48, Jeff GAZET wrote:

>Hi,
>
>i'm not sure about the way to limit extensions into the search tree.
>I think some code will be easier to understand than my english. Example :
>
>search(int depth,int alpha,int beta...)
>{
>int base_extended=0, extended;
>
>if(InCheck(side)) {depth++; base_extended+=ONEPLY;}
>
>foreach(move)
>   {
>   extended=0;
>
>   if(is_pawnn_push_7(move)) {depth++; extended+=ONEPLY;}
>   if(is_recapture(move)) {depth++; extended+=ONEPLY;}
>
>   if(extended>ONEPLY) {extended=ONEPLY;}

"extended" possibly reduced, but "depth" not reduced.

>   if(base_extended+extended>TWOPLY) {extended=0;}

again, "extended" reduced but "depth" not reduced.  And it would make
more sense to set extended to 1 or you will extend less when the
total is 3 than when it is 2.

>   domove()
>   score=-search(...);
>   undomove()
>
>   if(extended) {depth-=extended;}

extended might be 0, with depth being much larger than it started
out the iteration as.

>   }
>}
>
>Is that right ?

no, see above comments.
Angrim




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