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Subject: Re: New idea for crafty

Author: Robert Hyatt

Date: 11:28:38 07/27/00

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On July 27, 2000 at 14:00:06, pavel wrote:

>On July 27, 2000 at 13:41:24, Robert Hyatt wrote:
>
>>On July 27, 2000 at 13:10:44, pavel wrote:
>>
>>>
>>>is it possible to make crafty acces the position.lrn the same way it accesses
>>>the egtb? in this case, you dont have to worry about loading the lrn file every
>>>time to the hash table, and also the size wont be a problem. since crafty can
>>>deal with 20gb of egtb it shouldnt be a problem with few mbs of learning file.
>>>Or am I wrong ? will it cost crafty some speed ? or it is not possible to code
>>>is such way?
>>
>>The problem is this:  And EGTB has all possible scores for a given set of
>>pieces.  The position.bin file has a few positions from wildly separated
>>positions in many games.  A hit is so unlikely it hardly ever happens.  It
>>is most useful when someone takes crafty out of book, and for the first 10
>>moves, Crafty is doing fine, but then they walk it into a trap it didn't
>>see.  Prior to "result learning" this could cause problems, as the book line
>>looks fine, but it loses later.  With position learning, it will _still_
>>play the same book line, but it will vary and play a different move somewhere
>>before the point where it failed low and lost when the position was saved.
>>
>>In tournaments, I would not use it at all, since I would never let it play
>>the same opening twice in one tournament...  On ICC, it helps sometimes, but
>>the book is wide enough that it isn't used very much at all.  I doubt it would
>>affect it much if it was turned off.
>
>I should have been more clear , I was interested in position.lrn not book.lrn.
>so wont the concept be effective with position.lrn?

I was talking about position.bin/position.lrn.  Book learning only works
in two cases:  (1) after 10 moves out of book, the score is bad.  It marks
the latter part of the book line to avoid it next time;  (2) after a game is
lost, the latter part of the line is marked as bad.

But in position learning, it is useful _after_ we are beyond the threshold
where book learning works.

It operates as I described by adding permanent entries to the hash table so
that a repeat of this game will produce a different move.




>then It wont deal with only the first 10 moves after book but throughout the
>game? or there is a move limitation.?
>I am so interested about crafty learning feature, I always facinated about
>computer chess programs with *effective* learning features. and crafty is the
>only one that has a "good" learning feature AFAIK. Also is there any other way
>that learning can be tuned in to computer chess? which is much more effective
>with fewer limitations?
>also what is cooking with crafty? seen crafty17.13 play on chess.net
>what are your future plans? like to share?
>thanks for the explanations
>pavel
>
>>>but if you look at the bright side, "if" crafty comes in the same position twice
>>>things will be "faster for him to search", he will know the outcome of the game
>>>within his evaluation. I know the possiblity of crafty coming to same position
>>>is "dubious", but if you play 1000s of games doesnt the possibility gets
>>>narrowed? also it is possible to make crafty "learn" through analysys within
>>>CDB, its faster and effective IMO. or you can create a "universal" learning file
>>>from thousands of games played by crafty online.
>>>well I may be wrong since I a not an expert.
>>>but IMO its not a bad idea............. yes  IMO ;)
>>>thanks
>>>pavel.
>>>
>>>ps, ofcourse the post is mainly indicated for Dr, Hyaat, but others' comments
>>>are appreciated. thanks. pavel



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