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Subject: Re: Deeper blue was probably a root processor

Author: Robert Hyatt

Date: 13:23:01 07/22/00

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On July 22, 2000 at 14:08:13, Amir Ban wrote:

>On July 22, 2000 at 13:28:28, blass uri wrote:
>
>>Deeper blue had a positive evaluation before trading queens.
>>
>>The evaluation of Deeper blue was based on Deeper blue's logfile
>>
>>9(6)  3 T=46  34...Qxf1
>>10(6) 2 T=130 34...Qxf1
>>11(6) 2 T=168 34...Qxf1
>>
>>The evaluation when deeper blue started to ponder (hash guess Rxf1) was
>>
>>7  (4) -30
>>7  (6) -66
>>8  (6) -50
>>9  (6) -50
>>10 (6) -50
>>11 (6) -48
>>
>>Deeper blue lost 0.5 pawn in the evaluation and the only reason that I can
>>explain it is that it is a root processor.
>>
>>I guess that something like this cannot happen to Deep Junior because it is
>>probably more knowledge based program.
>>
>>Uri
>
>I thought that the host nodes would calculate piece-square tables for each
>subtree before giving it to a processor, which is not the same as preprocessing.
>If what you say is true, it indicates preprocessing, and that's an astonishing
>discovery.
>
>From the logs I remember that there is no hashtable persistence. Hashtable
>persistence and preprocessing cannot coexist.
>
>Amir


Sure it can.  I do _both_ in crafty.  I simply make a note when I change
something in preeval.c and rip thru the hash table and mark every score as
"no good" (I leave the moves alone as they are still likely reasonable).

I don't change things at the root for every search.  I probably change things
2-3 times per game, max...



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