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Subject: Re: Thinker 4.6b third after 1st round!

Author: Robert Hyatt

Date: 17:08:37 06/01/04

Go up one level in this thread


On June 01, 2004 at 19:25:41, Sune Fischer wrote:

>On June 01, 2004 at 18:39:46, Robert Hyatt wrote:
>
>>>We wanted to know what the strength relations were with learning off, now we
>>>know.
>>
>>Why?
>
>Mainly because you want reproducability, it's no good to have an engine that's
>not performing at a constant level.
>
>Ie. suppose I play a match against Crafty, then I change something in my engine
>and wants to see if it got better.
>If Crafty learns, my engine will probably do worse even if it is an improvement.
>
>Surely you can see why that is a nonsese experiment to do, learning _must_ be
>switched off or I simply cannot test against Crafty.

There is a solution.  Clear the learning before you start a test.  But even
then, you have  _real_ problem because there is some randomness built into my
move selection logic to provide variety.  If you play a 20 game match, make
changes, and play another 20 game match, comparing the results is less than
worthless...


>
>> Do you want to know the strength relation with the evaluation turned off?
>>Selective search turned off?  Etc???
>
>Actually, I would not mind that.
>I'd like to know exactly where Crafty's strengths are compared to Frenzee's.
>:)
>
>-S.


You can easily answer that.  But you also wouldn't publish a result of such a
match without clearly identifying that Crafty was badly handicapped.  That was
the point.  If someone reads "book learning disabled" and they don't know the
whys and whatfors about book learning, they might say "so what, no big deal"
when it really is.

My philosophy has _always_ been one of "don't whine about a problem, fix it."

I recall at the 1978 ACM event, Slate/Atkin were playing Belle, and they were
jumping up and down because (a) they only dumped the PV at the end of an
iteration and they didn't know whether their program had seen a coming tactical
problem or not and (b) they could only hope that if it did see the problem it
would have enough time to find a solution.

I thought about that and the next year Blitz (and later Cray Blitz) dumped the
PV each time it changed to keep the operator (me) informed about what it had
seen and it also used the original "using time wisely" idea of extending the
time limit when the score dropped.  Now I didn't have to worry once it saw a bad
score, because it would use a lot more time to try to avoid the problem.

Several years ago Ed was complaining about "duplicate" games in the SSDF testing
that was being done.  I thought about that and decided "rather than complaining
about duplicate losses, I'm going to simply avoid them by having crafty notice
that it got into trouble in an opening and not play it again for a while."  That
is where my "book learning idea" was founded.  A problem that you could either
complain about (does it make sense to let a program lose the same opening over
and over and count that against it and for its opponent?) or solve.  I chose
"solve" and have not had the problem happen to me, at all...

Of course if you turn it off, the problem comes right back, bigger than life,
and sticks around.




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