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Subject: Re: Risky play

Author: Robert Hyatt

Date: 06:11:58 04/09/01

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On April 09, 2001 at 01:35:12, Vine Smith wrote:

>On April 08, 2001 at 22:37:25, Robert Hyatt wrote:
>
>>On April 08, 2001 at 05:16:40, Vine Smith wrote:
>>
>>>So I get the impression that when I try adjusting the tropism, king safety
>>>factors, etc., I'm doomed to disappointment, I won't get "immensely aggressive"
>>>Crafty, so much as "immensely unsound" Crafty. Well, I'll take a look anyway. I
>>>just had ver. 18.9 analyze a game where an IM did a very bad thing to me at the
>>>National Open this year -- Crafty (along with every other program I've had look
>>>at this, including Fritz 6 and Century 3) doesn't understand what's going to
>>>happen until it's way too late. But perhaps the vicious attack my opponent
>>>launched will look more interesting to Crafty with heightened tropism, and a
>>>higher bonus for reducing my king's safety -- it's too deep to spot through
>>>normal analysis.
>>
>>
>>The problem will turn into balancing the aggressiveness vs its normal positional
>>skills. It has a pretty good concept of pawn structure, endgames, etc.  If the
>>king safety aggressiveness overwhelms these terms, then you will get some
>>aggressive play that leaves it in dead lost positions when the attack doesn't
>>work.
>
>Well, that sometimes happened to Tal. But whose games are more entertaining,
>Tal's or Petrosian's (yes, I know, some will indeed say Petrosian)? However, so
>far I haven't got anywhere with tropism 125-150, asymmetry 25-50, so I guess
>it's time to ratchet up king safety itself as well. How small are these
>positional values versus material values? I'm trying to get the program to spot
>an exchange sacrifice based on general principles alone, because there's no way
>it's going to search deep enough to see the concrete justification. If it
>sometimes incorrectly sacrifices as well, so be it. Human players carelessly
>toss material around all the time, it's time programs join them!

The scores can get pretty large.  IE king safety can go way beyond a pawn,
and when you factor in the second order stuff, it can go beyond 2 pawns.  The
default for asymmetry is -30 to -40 depending on the version.  +40 to +50
should begin to make a difference.

When you change one of those it should display a vector of numbers showing how
the score will climb or fall as the feature becomes more pronounced or
significant.



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