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Subject: Re: passed pawn evaluation.

Author: Robert Hyatt

Date: 13:25:06 01/12/04

Go up one level in this thread

On January 12, 2004 at 13:22:08, Frank Phillips wrote:

>On January 12, 2004 at 13:04:27, Robert Hyatt wrote:
>>On January 12, 2004 at 11:07:19, Daniel Clausen wrote:
>>>On January 12, 2004 at 10:02:07, Robert Hyatt wrote:
>>>>give white two pawns on d2/e2.  Give black two pawns on a2/h2.  Both kings
>>>>in the center.  Which side do you like?  :)
>>>Black - even if the black pawns wouldn't be so advanced and would still be on
>>>a7/h7. :)
>>>Problem is, I wouldn't really know what to code here. Of course you can code
>>>something so the engine won't exchange all pieces so it won't end up in this
>>>hopeless situation. But maybe it would be better to not let this pawn structure
>>>occur earlier in the game already, even if there's still pieces on the board.
>>>Sheesh, hard decision! :)
>>What you do is scale the connected bonus to material, and inversely scale the
>>isolated (passed) penalty to material.  More material, connected is better,
>>less material, they are equal, no material, isolated are way better...
>>This was somthing pointed out to me by Roman (GM) on ICC a few years ago.  I
>>told the story here multiple times and won't repeat unless someone asks...
>I am asking :-)

I logged on one afternoon and Roman was waiting.  "Bob, you have _got_ to fix
this in Crafty" and he proceeded to show me a position where Crafty thought it
was better (like the one I described above with Crafty having the connected
passers).  He then explained why it was wrong, which was actually obvious of
course _after_ he pointed it out.

The reason he pointed it out was more amusing however.  Another GM on ICC
(one Roman did not like) had found this weakness and was winning 2 of every
3-4 games against Crafty, something that GM players just don't do at blitz
time controls.  He wanted me to fix it to stop the guy from "milking points"
and having a higher rating than he had.  I fixed it that night and when I
logged on the next day, I had one message from Roman.  Simply "better".  I
looked and Crafty had won like 18 and drew 2 against this GM late the previous


GMs are funny people at times...


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