Evaluation of material imbalance (a Rybka secret?)
Posted: Thu Dec 06, 2007 10:21 pm
Like many, I think, I have often wondered what could be the secrets of Rybka. One particular feature that was often hinted at and seems to be indirectly confirmed by the fact that Larry is now part of Rybka's team, is the precise evaluation of material imbalances.
The original article by Larry Kaufman, a highly recommended reading, is here:
http://mywebpages.comcast.net/danheisma ... alance.htm
A short while ago, I decided to do some investigation on my own and tried to reproduce Kaufman's experiment, but this time with the help of some tool. For me, modifying Kiwi was an obvious choice since I know the code well and Kiwi includes a robust PGN parser.
What I'm trying to do: analyze and collect data for material imbalances over a large collection of games, and use the data for... something! Ideally, a chess engine will use the data to properly evaluate the material situation on the board, rather than relying on values that are good but only "on average".
But first, the data. I have put everything on this page:
http://www.ascotti.org/programming/chess/mat_stats.html
Interpreted data, statistics and source code. Sorry to put on external link but the HTML page alone is well over 100K.
Now for the help request! I have several questions...
1) what do you think of this approach?
2) can you spot some mistake or need more information?
3) if the approach is good, what could be a good way for an engine to use this data?
Of course all of this is free to use in any engine, I really hope we can make this approach work!
The original article by Larry Kaufman, a highly recommended reading, is here:
http://mywebpages.comcast.net/danheisma ... alance.htm
A short while ago, I decided to do some investigation on my own and tried to reproduce Kaufman's experiment, but this time with the help of some tool. For me, modifying Kiwi was an obvious choice since I know the code well and Kiwi includes a robust PGN parser.
What I'm trying to do: analyze and collect data for material imbalances over a large collection of games, and use the data for... something! Ideally, a chess engine will use the data to properly evaluate the material situation on the board, rather than relying on values that are good but only "on average".
But first, the data. I have put everything on this page:
http://www.ascotti.org/programming/chess/mat_stats.html
Interpreted data, statistics and source code. Sorry to put on external link but the HTML page alone is well over 100K.
Now for the help request! I have several questions...
1) what do you think of this approach?
2) can you spot some mistake or need more information?
3) if the approach is good, what could be a good way for an engine to use this data?
Of course all of this is free to use in any engine, I really hope we can make this approach work!