Author: Robert Hyatt
Date: 07:00:06 05/15/00
Go up one level in this thread
On May 15, 2000 at 03:35:07, pavel wrote:
>Hi guys,
> Can anyone tell me how the positional.lrn of crafty works? I know that
>its probably explained in the crafty.doc, but i couldnt find answers to some of
>my questions (or i missed them). Anyways I wanted to know how the positional.lrn
>works....as in, how does it chose its move to save it in the positional.lrn
>file. Ofcourse it doesnt save all its move from a single game, but which moves
>does it consider to save it to the file? and how does it avoid them if
>encountered in the future? Thus it save the "good" moves or the "bad" moves?? or
>both?
>---------------------------------------------------------------------------
This is a pretty well-known approach to simple learning. Documented by Dave
Slate in an oldish JICCA issue. Basically whenever the eval drops
significantly, the score and position are stored in position.bin... and when
a new game is started, everything in position.bin is copied into the hash table
and marked 'permanent'. If you try the same game again, it will see the threat
several moves earlier and play different.
It only stores 'bad' things, not 'good' things.
position.lrn is an ascii version of position.bin that can be shared with others
running crafty.
In the following, the three values in {} are the score in 1/100ths of a pawn
(-300 is - 3 pawns), the best move displayed as an integer, and the depth in
units of 1/60th of a ply.
-----
>What does these logs mean? I understood it giving a fen position for each 'logs"
>but what is the numbers below them? eg, {-1582 22964 540}. the best part is it
>also gives the dates ;)
>
>
>[White "Crafty 17.9"]
>[Black "unknown"]
>[Date "2000.05.15"]
>setboard /4B2p/6p/2bk/p/6PK/1r// w
>{-1582 22964 540}
>[White "Crafty 17.9"]
>[Black "unknown"]
>[Date "2000.05.15"]
>setboard /7p/6p/2bk2B//p5PK/1r// w
>{-1613 20646 480}
>[White "Crafty 17.9"]
>[Black "unknown"]
>[Date "2000.05.15"]
>setboard /7p/6p/2b/4k/p5PK/1r/2B/ w
>{-1638 6038 480}
>[White "Crafty 17.9"]
>[Black "unknown"]
>[Date "2000.05.15"]
>setboard 3r1r1k/p3bPpp/2bp1n/5R/1q1BP/1Bp/PPP1Q1PP/1K1R/ w
>{-88 54427 480}
>[White "Crafty 17.9"]
>[Black "unknown"]
>[Date "2000.05.15"]
>setboard 3r1r1k/p3bPpp/2bp/5R/1q1Bn/1Bp/PPP3PP/1K1R1Q/ w
>{-243 38025 480}
>-------------------------------------------------------------------------------
> Now about CBD database program, I find it very "kool" freeware product
>;). an excellent thing to analyze your favourite games with crafty. But there is
>something differant about analyzing with crafty through or without CBD or any
>other programs. It is so because if you analyze your games with crafty through
>CDB it tends to save its "bad" or "good" moves in the positional.lrn file. Also
>another thing is that it logs more in the positinal.lrn file if analyzed under
>CDB. Let say for example, yesterday i played a game between "crafty vs TCB" and
>crafty saved 2 logs to its positional.lrn file. The game was 15 min per side,
>later that day i made crafty analyze that "whole same game" under CDB for an
>hour, but this time it did 7 logs to positional.lrn file !!.
> Another question, If i make crafty analyze Most of its game under CDB (i have
>more than 200 games save in PGN), and as a result make it learn from its
>"mistakes" made in its previous games. Wont it make "my crafty" "sharper"? and
>thus avoid those positional mistake made earlier?
>thanks
>Pavel
>
>ps, i guess i ask too many questions, and also i hope "Bob" answers to my
>questions ;)
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