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Subject: Re: Crafty and single-computer winboard matches

Author: Robert Hyatt

Date: 12:30:48 10/06/99

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On October 06, 1999 at 13:44:05, Ed Schröder wrote:

>>Posted by Didzis Cirulis on October 06, 1999 at 06:58:16:
>>I see one limitation in this, (correct me, if I miss something):
>>
>>If you play using Rebel Century on both PCs, there will be easy for PB to
>>guess
>>the next possible move as the same program is running as opponent. Maybe take
>>another opponent (Hiarcs 7.32 etc) and play
>>
>>PC-1: Rebel Century PB=ON / TC 30 seconds
>>PC-2: Hiarcs 7.32 PB=ON / TC 30 seconds
>>
>>and then,
>>
>>PC-1: Rebel Century PB=OFF / TC 60 seconds
>>PC-2: Hiarcs 7.32 PB=ON / TC 30 seconds
>>
>>Didzis Cirulis
>
>True point indeed.
>
>On the other hand playing Rebel-Rebel means that opponents are 100%
>equal regarding strength.
>
>Ed
>
>PS, sofar it's 6-3 in favor of the PB.


I'm going to make a list of all the reasons why two programs, one computer, is a
bad thing to do:

1.  a program might not be well-adjusted in how it uses its time when it is not
allowed to "ponder".  Crafty is an example.

2.  a program might not be well-behaved and do some unexpected computation after
it sends the move to the referee program.  IE in crafty, I send the move, then I
do the learning stuff after 10 non-book moves have expired.  This 'learning
cycle' can take 2-3-4 seconds with a really large book and a long opening line
in the book.  Imagine what that does to a game/1minute time control that many
are using in winboard/xboard?

3.  a program (ie crafty) might do other things after it annouces its move, such
as malloc()'ing a large buffer for (say) learning or whatever.  What does a
large malloc() do to the other program?  swap it out?

4.  A program (ie chessmaster) might poll for input, consuming 1/2 of the cpu
even though it is not 'thinking'.

There are _too_ many things a program _might_ do.  I'll bet not one person
gave any thought to a "learning cycle" in crafty, yet it does it in every game.
And it steals 2-4 seconds of time from the opponent.  In short time controls,
that might be important.

If I _know_ people are testing like this, I'll bet I can raise Crafty's rating
by 100 points minimum.  I won't say how, but it shouldn't take too much
imagination to figure it out.  :)  And with that said, why bother testing in a
way that is obviously potentially unreliable.  For fun, sure.  But reporting
the results as "A beats B" is not very scientific...  A might not actually
be able to beat B, he just might have a smarter programmer that takes advantage
of a flawed testing methodology...

:)

Bob



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