Author: Stuart Cracraft
Date: 14:20:28 09/23/04
Go up one level in this thread
On September 23, 2004 at 13:14:32, Stan Arts wrote: >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 One of the very first things a master I was taking lessons from said to me was "Beware trading pieces, it advances the enemy who recaptures". If you think about this, it is often true. By giving up the tempo of the capture, you have advanced the enemy defender who recaptures. Stuart
This page took 0 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.