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Subject: Re: Vincent

Author: Matthew Hull

Date: 06:03:17 05/07/04

Go up one level in this thread


On May 07, 2004 at 08:02:23, Tord Romstad wrote:

>On May 07, 2004 at 07:09:54, Sune Fischer wrote:
>
>>On May 07, 2004 at 06:32:12, Tord Romstad wrote:
>>
>>>On May 07, 2004 at 04:10:01, Sune Fischer wrote:
>>>
>>>>Ie. if Movei could score 40% against Crafty I wouldn't be surprised. Gothmog has
>>>>scored 50% in some tests I believe,
>>>
>>>You are probably referring to some of the match results I have reported
>>>myself.  The last couple of times I have played matches against Crafty,
>>>the scores have been almost exactly 50%.  But it should be pointed out
>>>that the match conditions are not very fair to Crafty, for two reasons:
>>>
>>>1. I play my matches on a single-CPU machine, with pondering disabled.  As
>>>   is well known, Crafty is seriously crippled without pondering, because
>>>   its time management doesn't work well.
>>
>>Perhaps it is just Gothmog that is crippled with ponder on? :)
>>I imagine that you, like me, hasn't spent a lot of time testing with ponder on
>>because we don't have dual machines to test on.
>>
>>In any case if an engine is performing like the author designed it then it's
>>fair game.
>>
>>Anyway, what is different in Crafty's TM with ponder on?
>
>I don't know the details; we should probably ask Bob.  I just recall
>numerous occasions in the past when somebody reported a bad match result
>for Crafty and Bob explained that the match result didn't mean anything,
>because Crafty was not designed to work without pondering.
>
>For this reason I don't test against Crafty very often.
>
>>>2. My Crafty executable is compiled using GCC on a Linux machine.  The
>>>   Windows version of Crafty is probably compiled using the Intel or
>>>   Microsoft compiler (unlike Gothmog, which uses GCC on all platforms),
>>>   which reportedly produce much faster code.
>>
>>Ok, but using a better compiler is not really a strength of the engine. I think
>>using the same compiler makes a good basis for comparison since Gothmog would
>>probably get the same kind of boost with a better compiler.
>
>No.  Gothmog probably wouldn't even compile with another compiler.  I don't
>really know the C programming language.  I program in a mix of ANSI C,
>Unix-specific functions, and some GNU-specific extensions, and I have no
>idea which of the many functions I use are portable.  In theory it would
>of course be possible to port my engine to work with the Intel or Microsoft
>compiler, but it would probably require some non-trivial work.
>
>Bob has already done this work.  When comparing Gothmog and Crafty as
>Windows engines (which is what the majority of people care about), it is
>perfectly fair that Crafty benefits from a better compiler.
>
>>>I also think it is possible that Gothmog performs better against Crafty
>>>than against other engines of similar strength, for reasons of playing
>>>style.  Crafty's lack of king safety eval makes it rather vulnerable to
>>>Gothmog's very aggressive play.
>>
>>I can't figure out how strong Gothmog is.
>
>Neither can I.  It appears to be in the same league as Frenzee and Movei,
>but on the other hand it also scores around 50% against Yace Paderborn.  It
>seems to be hundreds of rating points weaker than Amateur, The Baron and
>Butcher.
>
>Of course, this doesn't add up at all.
>
>>Sometimes it appears almost to be at the Ruffian level, other times it has
>>problems with more mediocre engines.
>
>Yes, exactly.  Confusing, isn't it?
>
>>Perhaps it really does have something to do with style, or simply too few games
>>played and it really is somewhere inbetween.
>
>Gothmog is a very unbalanced engine.  It is quite good in some respects, and
>horribly bad in others.  The search and eval is fundamentally (and
>intentionally!) unsound, in an attempt to make the engine play an interesting
>game.  This works very well in some cases, but sometimes has catastrophic
>consequences.
>
>I think it is relatively easy to tune any reasonably strong engine to score
>almost 100% against Gothmog.  Ask Anthony if you want to know how.  :-)


Why don't you let Gothmog go on ICC for awhile?  Do you not have a machine to
dedicate for that purpose?  That is the way to collect and analyse games against
a wide variety of opponents.   And of course, we get to watch.  Gothmog does
play interesting chess.  Share the fun.


>
>Tord



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