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Subject: Re: Question to Bob Hyatt

Author: Brian Richardson

Date: 09:59:33 05/30/02

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On May 30, 2002 at 03:55:29, Olaf Jenkner wrote:

>>On May 29, 2002 at 18:25:05, Olaf Jenkner wrote:
>>
>>>I noticed a big difference between Crafty 18.13 and 18.14 in a
>>>special position and don't understand what happened.
>>>Maybe you can explain it.
>>>
>>>See this position:
>>>
>>>[D]3B4/1r1kp3/r2p1p2/b1pPP1p1/1pP2PPp/pP5P/P2K4/8 w - - 0 1
>>>
>>>After 1.e6+ K:d8 2.f5+ it is a draw.
>>>
>>>Version 18.13 finds the move after 35 min at depth 16
>>>   and gives the evaluation  -12.40
>>>Version 18.14 finds the move after 150 min at depth 17 gives
>>>   and gives the evaluation  -12.34
>>>

Wow...35 and 150 minutes of search time...not exactly typical, even for
standard time control games.  Note that the eval is nearly identical, which is
important.  The ply and time changes could be due to a slight evaluation
difference deep in the tree that postpones things another ply, which if ply 16
is 35 min, is quite reasonable to expect to take about 5x longer to search a ply
deeper.



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