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Subject: Re: Help - Suggestiong for setting the Delta value in the QSearch

Author: Stuart Cracraft

Date: 09:17:27 07/02/04

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On June 30, 2004 at 20:17:49, William Bryant wrote:

>On June 30, 2004 at 19:59:12, Stuart Cracraft wrote:
>
>>On June 30, 2004 at 19:50:23, William Bryant wrote:
>>
>>>I am looking for suggestion or references for setting the Delta value in the
>>>QSearch used to filter captures.  Those captures that don't exceed the Delta
>>>value are pruned even though they may be winning captures.
>>>
>>>Thanks in advance.
>>>
>>>William
>>
>>Can you elaborate on what the delta value is?
>
>The idea behind the delta value is that if you are already behind a substantial
>amount of material, then captures, even winning captures, that only generate a
>small material gain are a waste of time in the
>qsearch.
>
>Therefore, in you call to generate the moves for the qsearch, you pass a delta
>value.  It the SEE value from the capture does not meet or exceed this value,
>then this capture does not need to be searched at this time because in the end,
>it won't make a difference.
>
>My old program used the followng:
>
>long Delta = alpha - DeltaWindow - (MATERIAL);
>gen_caps(Delta);
>
>where DeltaWindow is an amount of tolerance and MATERIAL is the material balance
>at this point
>
>I am looking to update this information as I rewrite my program.
>
>Ideas and suggestions please.
>
>William

Thankyou for your note. I'll take a look at Delta after SEE.



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