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Subject: Re: Questions:Extension,Pruning

Author: Robert Hyatt

Date: 18:21:41 03/25/02

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On March 25, 2002 at 18:41:52, TEERAPONG TOVIRAT wrote:

>
>Hi,
>
>I've a few questions.
>
>1. When we extend searching depth,which one should be
>stored as hashtable->depth  depth or depth+extension?


Whatever the depth is at the corresponding point where you will call
the Probe() function.  IE typically this is done at the top of search,
if you do it that way, then you have not applied any extensions at this
ply when you do the probe, so you must not apply any extensions when you
do the store to keep things consistent...



>
>
>Search(alpha,beta,depth)
>{
>
>Probehash()
>if(check) extension+=...
>
>-Search(-beta,-alpha,depth+extension-1)
>
>Storehash() => here with depth or depth+extension ???


Without or you will discover a _huge_ bug...



>
>}
>
>
>2.After I add Extended Futility Pruning,cutting off at prefrontier
>nodes, to my program,it miss mate in 1.
>How to fix this?

Don't do futility pruning.  :)



>
>3.Recapture extension makes my program much slower.
>How much benefit do we gain from it?
>



Good question.  I believe it helps.  But how much is a guess...



>
>Thanks for any comment,
>Teerapong



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