Author: Stan Arts
Date: 10:14:32 09/23/04
Hi Today, I've been experimenting with anti-piecetrading again. I have a preference for Neurosis to try to keep it's pieces, to play more "human"like, and offer more resistance. I've always had a system for this, each new gamemove the computer's pieces are counted, and in the evaluationfunction the current number of computer's pieces is compared with this root-count. Then the penalty for each traded piece is also dependant on how much ahead or behind in general. This seems to work ok for a single position, and sort of works as expected. But what's worrying is that this can sometimes give hashtable-instability when re-using hashscores for next gamemoves, because it's root-dependant. So I wonder, what do you do to to solve this problem? Do you even use any anti-trade code or none at all? Because there seem to be a few other problems too. Even with small values, (I was using 0.03 pawn for a light piece, in equal positions) instead of having a "human"like tendency not to give away it's pieces, it's going to play very cramped to try and keep it's pieces. (hiding them away, in dumb ways only a computer can) And is happy to play poor positional moves, giving away positional advantages by the penalty-ammount for trading pieces, instead of the effect I wanted. :) So often making weak moves in quiet positions. Often expecting the opponent to capture it's pieces. So expecting nonsence lines. And asymetry. Although with the system as I described above it's back to 0 again for each new capture-gamemove. (But with a change in score, which can give the hashtable-problems.) Also, this afternoon I've turned the code off for the first time in a long time, and to my surprise/shock it really does seem to play a bit better..I hadn't thought anything of it in a long time. (oops) What are your thoughts on this? Maybe such code is better left out all together, and values for a piece being "good" or "bad" and so are much more important anyway? Greetings Stan
This page took 0.01 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.