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Subject: Re: Futility

Author: Michael Henderson

Date: 18:07:07 10/15/04

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On October 14, 2004 at 10:28:16, Stuart Cracraft wrote:

>I don't think I'm implementing it properly because my node
>reductions are not happening.
>
>My implementation is based on Ed Schroder's comments on
>page 8 of his comments (Search Techniques in Rebel (Futility
>Pruning)
>
>
>   makemove
>   if depth == 1 (i.e. one more ply for sarch)
>   if side just moved king was in check before the move or
>   if side on move king is in check after the move or
>   if move is a capture or
>   if (alpha < material[sideonmove]-material[sidejustmoved]+
>               pcsq[sideonmove]-pcsq[sidejustmoved] + 3 pawns)
>   then do normal search with depth-1
>   but if all of the above are true then unmakemove and
>     return material[sideonmove]-material[sidejustmoved]+
>            pcsq[sideonmove]-pcsq[sidejustmoved]
>
>   as well as the above but with depth == 2 and 5 pawns instead of 3.
>
>The only thing I can think of doing is not doing the makemove at
>the top and doing it only if the futility is avoided due to one
>of the conditions being true.
>
>Stuart

I think that not many nodes fit that description in 1 second searches.  Also I
think it's a rebel-type improvement...i think he sometimes states that stuff may
not work for you.

Michael



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