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Subject: a CM8000 bug -- Attn: John Merlino

Author: William Penn

Date: 14:55:12 12/10/00

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Please take a close look.  I believe that James T. Walker has put his finger on
the evaluation problem as expressed in scores:  There is apparently a bug when
scores are in the range of +1 to -1 which fails to put a minus sign on negative
scores.  The minus sign is only affixed to the score when it is less than -1.
WP


On December 10, 2000 at 17:11:19, James T. Walker wrote:

>On December 10, 2000 at 16:58:07, William Penn wrote:
>
>>To Jeremiah & James...
>>
>>Thanks to Jeremiah Penery and James T. Walker for your replies and suggestions.
>>
>>For some unknown reason, I am unable to post a reply in the original thread
>>below. I just get a message saying the thread doesn't exist, hasn't been posted
>>yet, may have been deleted...etc.  I may have a corrupted cookie, or something.
>>
>>There is a dearth of documentation about CM8000, and nothing in the instructions
>>about such things. We are apparently dependent on John Merlino to come along and
>>fill in the gaps, insofar as he knows the solutions/answers.  I've heard from
>>him before on this subject, and am not sure that he knows the answer.  It may
>>require the chess engine's author to take a look at it in a very patient way, if
>>he is willing, but that could be a problematical proposition too!?
>>
>>Bottom line: I can't be confident in CM8000's scores generated when evaluating
>>positions, and that's pretty fundamental.
>>WP
><snip>
>
>Hello William,
>I have finally been able to understand the problem.  You are right about
>ChessMaster 8000 having a problem with the scores!  All scores below 1.00 are
>positive even when black is winning.  As soon as the score goes over 1.00 for
>black the scores show the minus sign.  This is a definite error in the GUI.  I
>don't think the engine has a problem since it is playing so well (except for not
>using it's time).  I think it's just a bug in the scores below -1.00.  I just
>finished a game in which the score was around 0.97 and I'm sure black was ahead.
> The scores then bounced from 0.97 to -1.01 back to 0.91.  I'm sure the position
>was not that wild.  It's just that all scores below 1.00 are positive.  I have
>noticed this before but could not put my finger on the problem.  I noticed that
>ChessMaster seemed to always think white was winning untill something drove the
>score past -1.00.  Then it shows scores like -1.21 indicating black is winning.
>This is definitely a problem for John to pass along.
>Jim



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