Sam Trenholme wrote on Wed, Sep 27, 2006 04:13 PM UTC:
I was playing around with ChessV and was able to set up a preset to modify it so that it would not be so greedy in the opening of Janus chess. Basically, with ChessV, it's possible to change the values of the pieces. What I did was make all of the pieces have one third of their normal value. For example, ChessV feels a pawn is worth 1000 points, a rook is 5000 points, and a queen is 9000 points.
What I did was make the pawn worth on 333 points, the rook only worth 1666 points, the queen worth 3000 points, and so on. What this does is make factors not directly having to do with material, such as the position of the pieces, three times more valuable. Once I did this, this is how ChessV handled Dan's gambit play:
1. Ah3 e5 2. f4 exf4 3. Nd3. Stock ChessV tries too hard to hold on to the pawn here: 3. ... g5?. However, by tweaking ChessV to only be one-third as greedy, ChessV responds with the much more sensible 3. ... f5 or 3. ... Ng6, depending on how much time we give ChessV to think about the position.
My experiments show that tweaking like this, when done for the course of the entire game, will make ChessV make some unsound sacrifices in the late mid-game and end-game, resulting in the 'stock' ChessV winning the game. However, if I have the tweaked version of ChessV play white only for the first ten moves, than give the stock pieces to the normal ChessV, the result is the same as giving both sides the stock pieces: White wins the game.
For Greg's info, this testing was done at an I-depth of 7 and with pruning and razoring disabled.
If Dan is interested, I'm willing to see how well he does against the tweaked ChessV (for the first ten moves, anyway).
What I did was make the pawn worth on 333 points, the rook only worth 1666 points, the queen worth 3000 points, and so on. What this does is make factors not directly having to do with material, such as the position of the pieces, three times more valuable. Once I did this, this is how ChessV handled Dan's gambit play:
1. Ah3 e5 2. f4 exf4 3. Nd3. Stock ChessV tries too hard to hold on to the pawn here: 3. ... g5?. However, by tweaking ChessV to only be one-third as greedy, ChessV responds with the much more sensible 3. ... f5 or 3. ... Ng6, depending on how much time we give ChessV to think about the position.
My experiments show that tweaking like this, when done for the course of the entire game, will make ChessV make some unsound sacrifices in the late mid-game and end-game, resulting in the 'stock' ChessV winning the game. However, if I have the tweaked version of ChessV play white only for the first ten moves, than give the stock pieces to the normal ChessV, the result is the same as giving both sides the stock pieces: White wins the game.
For Greg's info, this testing was done at an I-depth of 7 and with pruning and razoring disabled.
If Dan is interested, I'm willing to see how well he does against the tweaked ChessV (for the first ten moves, anyway).
- Sam