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Subject: Re: Result of Hash Table

Author: Bruce Moreland

Date: 13:07:49 01/20/98

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On January 20, 1998 at 15:22:51, Robert Hyatt wrote:

>On January 20, 1998 at 14:10:49, Stuart Cracraft wrote:
>
>>An error was discovered in the search/quiescence calling.
>>
>>The call to  the quiescence search was made
>>after the probe to the hash table, instead of before.
>>When this was moved to before the probe to the hash
>>table, the probe success rate jumped up to the kinds
>>of levels we're talking about here.
>>
>>The speed of the program jumped up 20% from 25,000 nps
>>to 30,000 nps on the same test suite and the hashing
>>success rate increased significantly from 14% to 40%
>>for the suite.
>>
>>--Stuart
>
>Your "bug" was correct.  You *always* probe before doing anything
>else.  That's the point.  What you did was make the current position
>probe fail by deferring it, so that a deeper position probe would
>succeed. You bumped up your probe hit rate, but check out your nodes
>to reach a specific depth.
>
>The probe should be the first thing you do.  Then the null-move
>search.  Then the regular search.

Yes.  It is important to understand that NPS is a useful measure only if
you are searching the same tree, and getting the same results.  If you
search a tree that is 20% larger, and your node rate increases by 10%,
this version is probably not good.  This sounds obvious but I think
people sometimes forget this.

bruce



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