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Subject: Re: Fritz won shredder,Century won Boris kogen(2286) in the israeli league

Author: blass uri

Date: 10:23:13 04/03/00

Go up one level in this thread


On April 03, 2000 at 11:52:08, Dave Gomboc wrote:

>On April 03, 2000 at 02:59:43, Ed Schröder wrote:
>
>>On April 02, 2000 at 18:41:22, Dave Gomboc wrote:
>>
>>>On April 02, 2000 at 18:24:06, Ed Schröder wrote:
>>>
>>>>On April 02, 2000 at 16:33:24, blass uri wrote:
>>>>
>>>>>On April 02, 2000 at 15:46:54, Dave Gomboc wrote:
>>>>>
>>>>>>It sounds like your tunable policy paid off, in terms of people discovering good
>>>>>>adjusted parameters?
>>>>>>
>>>>>>Dave
>>>>>
>>>>>Chess knowledge=25 is not an idea of me.
>>>>>
>>>>>I suggested to use it only after I read in Ed's site that Ed found that it is an
>>>>>improvement against computers and maybe also an improvement against humans.
>>>>>
>>>>>I found also (after I read that Ed found that knowledge=25 is an improvement)
>>>>>that Rebel(knowledge=0) does not lose in a result of almost 60:0 against
>>>>>Rebel(chess knowledge=500) at 7 plied depth and it convinced me that Rebel knows
>>>>>some important things even with knowledge=0.
>>>>>
>>>>>I think that the numbers of the chess knowledge parameter were misleading and
>>>>>the minimal number should be clearly bigger than 0.
>>>>>
>>>>>I believe that this is the reason that people did not try to reduce the chess
>>>>>knowledge parameter in the Rebel century personality contest.
>>>>>
>>>>>Uri
>>>>
>>>>I also did not expect it either that lowering the Chess Knowledge parameter
>>>>would make Rebel stronger. In my tests I always increased the value of
>>>>the Chess Knowledge parameter. When I did a test with [Chess Knowledge=25]
>>>>(it was just curiosity) I was surprised to see the enormous speed gain of
>>>>the search. Then [Chess Knowledge=25] suddenly had my full attention.
>>>>
>>>>So the improvement was discovered by accident. No real surprise as most
>>>>of the time it goes that way. Chess remains a mystery, it is like a maze
>>>>of 2^64 entries and no exit.
>>>>
>>>>Ed
>>>
>>>That's kind of funny, but I suppose it shouldn't be completely unexpected.  If
>>>you try increasing the amount of knowledge, and it performs worse, it makes
>>>sense to try reducing it instead... and there have been other stories of people
>>>removing knowledge from their programs before.
>>>
>>>Dave
>>
>>It is more complicated than that. The higher one set the [Chess Knowledge]
>>parameter the better quality of moves the thing will produce. Just play
>>a 100 games engine-engine match based on a fixed depth time control. The
>>higher you set the [Chess Knowledge] parameter the bigger the victory.
>>
>>So the [Chess Knowledge] parameter works and does the job it is supposed
>>to do. On the other hand a high value of the [Chess Knowledge] parameter
>>is responsible for loss in speed during the search which may lead to a
>>loss of a complete (iteration) ply. And losing an iteration ply seems to
>>be more valuable than the gain of the extra chess knowledge. No doubt this
>>is true for comp-comp but what if the topic is human-comp? Until now I
>>really can't tell. So far I have chosen that [Chess Knowledge=25] is also
>>better against humans. Am I completely sure? No...
>>
>>Ed
>
>I wouldn't be sure of it either.  I do think it's a good idea to trade off some
>search prowess to get better pattern recognition vs. humans, though.  Even if
>it's not stronger (and that is a possibility, as you suggest), it's probably
>more pleasing to play against.

The question is if increasing the chess knowledge from 25 to a bigger value
gives important knowledge that you can practically never see by search because
you need to search 20-50 plies forward to see the same thing by search with
chess knowledge=25.

I guess that it does not happen or almost does not happen otherwise using chess
knowledge=25 could not be a good idea.

Uri



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