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Subject: Re: question about passed pawn evaluation of crafty

Author: Robert Hyatt

Date: 20:28:29 04/01/03

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On April 01, 2003 at 22:12:24, Uri Blass wrote:

>1)I see in crafty's source code
>
>score+=pscore*passed_scale/100;
>
>What is the meaning of passed_scale?
>If I understand correctly the starting value is 100.
>I also see in option.c


This lets users scale that up or down to adjust the "personality".

Ie the default is 100, which means the passed pawn scoring is multiplied
by 1.0 (100/100).  If you set this to 50, then passed pawn scores would be
reduced by 50% which would make it "less aware" of passed pawns in the
endgame.  It can be set to zero for a "patzer" type mode where passed pawns
seem to not exist at all.  :)




>
>passed_scale=atoi(args[2]);
>
>I read in the source code that it is done only when "evaluation" command
>is used to adjust the eval terms but I am not sure if it can be done
>automatically by crafty in the middle of the game.
>



No it isn't...  It is only used for users that want to tweak the various
eval terms, usually to make it dumber.


>
>2)What is the exact definition of connected pawns in Crafty(I guess 2 pawns on
>2 files that are clos but I am not sure if they need to be in the same rank)?
>
>Uri

That is a good question.  I _want_ to say that the passers are on adjacent
files, and they are in contact with each other or _can_ be in contact with
each other.  I'll try to look at this to be sure, however...

OK  connected passers are passers on adjacent files.   Since they are passed
they can't be inhibited by opponent pawns.  But they don't have to be "touching"
or anything, just on adjacent files and both are passed.







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