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Subject: Re: Crafty 14.1 makes a horrible blunder

Author: Robert Hyatt

Date: 17:11:01 11/23/97

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On November 23, 1997 at 13:44:57, Keith Ian Price wrote:

>On November 23, 1997 at 09:20:08, Robert Hyatt wrote:
>
>>On November 22, 1997 at 23:44:51, Tim Mirabile wrote:
>>
>>>On November 22, 1997 at 17:14:03, Robert Hyatt wrote:
>>>
>>>>On November 22, 1997 at 16:18:00, Darrin Moon wrote:
>>>>
>>>>the problem is obvious looking at the log files.  You have corrupted
>>>>endgame databases.  There are *no* mate in 44's in the 3-4 piece
>>>>endings, so you have something wrong.  Most likely one or more (or all)
>>>>are corrupted.
>>>>
>>>>Here is a complete list of the 3-4 piece files and their sizes.  There
>>>>must be *no* deviations in file size:
>>>
>>>Perhaps he FTP'd them in ASCII mode instead of BINARY?
>>
>>
>>possibly.  Also these things can fill the drive when you unzip 'em,
>>which
>>can truncate one here or there.  But they *must* be correct, because
>>Crafty
>>probes them in a completely trusted manner.  If the file is corrupted,
>>bad
>>results will show up...
>
>Perhaps a quick checksum on the available tablebases, upon firing up
>Crafty would be a way to avoid unnecessary losses due to corrupted
>tablebases. Also, I believe I recall you saying that all of the 3 and 4
>man bases must be present. If this is true, then a count should be added
>also. Just a suggestion, in case Crafty were to be tested on SSDF for
>example.
>
>kp

the problem is that "quick checksum" is an oxymoron when you have the 5
piece
files as well.  try reading thru 2.5 gigs and checksumming each file...
and the
flag will fall before the first move is made.  :)

simplest solution is to watch the sizes...  I will try to dream up some
sort
of "certificaton maybe... such as reading the first/last byte of each
file
and checking it or some such thing...



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