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Subject: Re: probs with 6man EGTB

Author: Robert Hyatt

Date: 13:14:52 08/24/05

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On August 24, 2005 at 16:12:51, Peter Kappler wrote:

>On August 24, 2005 at 15:11:46, Robert Hyatt wrote:
>
>>On August 24, 2005 at 14:24:08, Ryan Peters wrote:
>>
>>>Can anyone verify that the 6man EGTB files Kbp v Kbp from the Crafty site
>>>ftp://ftp.cis.uab.edu/pub/hyatt/ are "clean" ?
>>>
>>>I have downloaded the 7 files twice now.
>>>
>>>kbpkbp.0.nbw.emd
>>>kbpkbp.1.nbw.emd
>>>kbpkbp.2.nbw.emd
>>>kbpkbp.3.nbw.emd
>>>kbpkbp.4.nbw.emd
>>>kbpkbp.5.nbw.emd
>>>kbpkbp.6.nbw.emd
>>>
>>>The Wilhelm utility v1.48 flags all as "defective" and in particular says that
>>>the last one kbpkbp.6.nbw.emd is corrupted. This is the lastest version of
>>>Wilhelm, but I am not sure that I trust this utility :). When I try to use them
>>>in either Deep Shredder9 UCI GUI or the lastest Chessbase GUI I get "wierd"
>>>results. I am successfully using many other 6man EGTB's downloaded from the
>>>Crafty site. Just this set is causing problems.
>>>
>>>Ryan
>>
>>
>>You might need to wait for the next version of that program.  Prior to building
>>one of these tables, eugene has only a "gut-feeling" about whether an 8 bit
>>value is enough or not.  He then plugged in his "gut feeling" into the egtb.cpp
>>code and we distributed it to the world.  Every now and then his "gut" was
>>wrong, and there is a deeper mate than expected, which requires a 16 bit value
>>rather than an 8 bit value.  This is encoded in the egtb.cpp source file and
>>requires a simple change to update.  The current crafty source has the most
>>recent egtb.cpp changes if you want to compare to see what is probably wrong...
>>
>>You either need a new egtb.cpp, or else don't try to use that particular set of
>>table files...
>
>
>What's the deepest mate you've seen in the 6-man tables?
>
>-Peter

I really haven't looked, but I know it went past the 8 bit value limit which is
roughly +127 to -128.



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