One of the Hardest Combinations Ever Played

[Kirk]

The weight of the pawn was increased and the weight of the Queen was greatly lowered. Knight was increased by a bit

The pruning and selectivity were both set low as well.

[Terry McCracken]

The weight of the pawn was increased and the weight of the Queen was greatly lowered. Knight was increased by a bit

The pruning and selectivity were both set low as well.

Unfortunately, not to useful in a practical game.

Still it was interesting.

Terry

[Kirk]

One thing I am uncertain of. I am not sure if lowering the value actually lowers the "true value" of the queen or just its willingness to sacrifice the piece.

Here is Tricky for what it is worth:

[ENGINE]
Name=Shredder 6 Tricky
Author=Stefan Meyer-Kahlen
Filename=Engine.exe
[OPTIONS]
Queen=25
Queen (Endgame)=99
Rook=50
Knight=125
Pawn=200
Forward Pruning=5
Selectivity=5
King Safety=60
Center Control=60
Pawn Structure=90
Pawn Structure (Endgame)=95
Bishop Pair=88
Bishop Pair (Endgame)=92
Knowledge=97

[Terry McCracken]

One thing I am uncertain of. I am not sure if lowering the value actually lowers the "true value" of the queen or just its willingness to sacrifice the piece.

Here is Tricky for what it is worth:

[ENGINE]
Name=Shredder 6 Tricky
Author=Stefan Meyer-Kahlen
Filename=Engine.exe
[OPTIONS]
Queen=25
Queen (Endgame)=99
Rook=50
Knight=125
Pawn=200
Forward Pruning=5
Selectivity=5
King Safety=60
Center Control=60
Pawn Structure=90
Pawn Structure (Endgame)=95
Bishop Pair=88
Bishop Pair (Endgame)=92
Knowledge=97

Thanks...This should work in ver. 7&8 as well.

[Kirk]

A slightly different version of this personality seems to find both lines:

[d]2r1q1kr/p3p2p/1p1pPbpB/4n3/4P3/2P5/PP2B2P/R2Q1RK1 w - - 0 22


Engine: Shredder 6 Tricky-Tahoma
by Stefan Meyer-Kahlen
14.01 0:07 +7.92-- 1.Rxf6 exf6 2.Qxd6 Rc6 3.Rf1 Rxd6 4.Rxf6 Rxe6 5.Rxe6 Qxe6 6.Bf3 (6.013.355) 817.0
14.01 0:36 +7.92 1.Rxf6 exf6 2.Qxd6 Rc6 3.Qxe5 fxe5 4.Rf1 Qe7 5.Kh1 Rxe6 6.Bc4 (29.981.200) 827.7
15.01 2:16 +7.69 1.Rxf6 exf6 2.Qxd6 Rc6 3.Qxe5 fxe5 4.Rf1 Rc8 5.Bg4 Qd8 6.e7 (114.399.571) 838.9

And

[d]6kr/4q2p/p3P1pB/1p2p3/P1r1P3/1BP5/1P5P/5RK1 w - - 0 6

Engine: Shredder 6 Tricky-Tahoma
by Stefan Meyer-Kahlen
10.01 0:02 +8.74++ 1.h3 Qe8 2.axb5 axb5 3.Kg2 Qe7 4.Rf2 Rxe4 5.Rf8+ Qxf8 6.e7+ Rc4 7.Bxc4+ Qf7 8.e8R+ (2.055.749) 797.4
10.01 0:02 +8.74 1.h3 Qc5+ 2.Kg2 Qe7 3.axb5 axb5 4.Rf2 Qe8 5.Rf5 Qa8 6.h4 Rxe4 (2.157.834) 798.3
11.01 0:03 +8.55 1.h3 Qe8 2.axb5 axb5 3.Kh2 Qe7 4.Be3 (2.960.452) 816.6
12.01 0:07 +8.80++ 1.h3 Qe8 2.axb5 axb5 3.Ba2 Rxe4 4.e7+ Rc4 5.Bxc4+ Qf7 6.Rxf7 g5 (5.788.592) 821.4
12.01 0:08 +8.80 1.h3 Qc5+ 2.Kh1 Qe7 3.axb5 axb5 4.Ba2 Qg7 5.Bxc4 bxc4 6.Rf6 (6.621.083) 825.9
12.09 0:17 +8.81++ 1.Kg2 bxa4 2.Bxc4 Qc5 (14.602.647) 844.2
12.09 0:26 +9.16++ 1.Kg2 Qe8 2.axb5 axb5 3.Ba2 Rxe4 4.Rf8+ Qxf8 5.e7+ Rc4 6.Bxc4+ bxc4 7.exf8R+ (22.186.874) 841.7
12.09 0:36 +10.30 1.Kg2 Qe8 2.axb5 axb5 3.Ba2 Qa8 4.h3 Qxe4+ 5.Kg1 Qf5 6.Rxf5 gxf5 7.b4 Rxc3 (31.205.229) 851.6
13.01 0:57 +10.05-- 1.Kg2 Qg7 2.Bxc4 bxc4 3.Bxg7 Kxg7 4.e7 Rg8 5.Rf3 (50.205.908) 868.4
13.01 1:08 +9.55-- 1.Kg2 Qg7 2.Bxc4 bxc4 3.Bxg7 Kxg7 4.e7 Rg8 5.Rf3 g5 (60.266.767) 873.6
13.01 1:16 +9.55 1.Kg2 Qg7 2.Bxc4 bxc4 3.Bxg7 Kxg7 4.Rf7+ Kh6 5.e7 Rb8 6.Kg3 Rxb2 7.e8Q g5 8.Rf2 (67.889.728) 882.0
13.15 1:23 +9.56++ 1.Ba2 bxa4 2.Bxc4 (73.492.745) 881.8
13.15 1:25 +9.91++ 1.Ba2 bxa4 2.Bxc4 Qe8 3.Bxa6 g5 (74.961.986) 879.6
best move: Bb3-a2 time: 1:35.625 min n/s: 877.518 CPU 197.3% nodes: 83.912.731

------------------------
[ENGINE]
Name=Shredder 6 Tricky-Tahoma
Author=Stefan Meyer-Kahlen
Filename=Engine.exe
[OPTIONS]
Queen=25
Queen (Endgame)=99
Rook=50
Knight=125
Pawn=200
Forward Pruning=5
King Safety=25
Center Control=60
Pawn Structure=90
Pawn Structure (Endgame)=95
Bishop Pair=25
Bishop Pair (Endgame)=25
Knowledge=400

[Terry McCracken]

A slightly different version of this personality seems to find both lines:

[d]2r1q1kr/p3p2p/1p1pPbpB/4n3/4P3/2P5/PP2B2P/R2Q1RK1 w - - 0 22


Engine: Shredder 6 Tricky-Tahoma
by Stefan Meyer-Kahlen
14.01 0:07 +7.92-- 1.Rxf6 exf6 2.Qxd6 Rc6 3.Rf1 Rxd6 4.Rxf6 Rxe6 5.Rxe6 Qxe6 6.Bf3 (6.013.355) 817.0
14.01 0:36 +7.92 1.Rxf6 exf6 2.Qxd6 Rc6 3.Qxe5 fxe5 4.Rf1 Qe7 5.Kh1 Rxe6 6.Bc4 (29.981.200) 827.7
15.01 2:16 +7.69 1.Rxf6 exf6 2.Qxd6 Rc6 3.Qxe5 fxe5 4.Rf1 Rc8 5.Bg4 Qd8 6.e7 (114.399.571) 838.9

And

[d]6kr/4q2p/p3P1pB/1p2p3/P1r1P3/1BP5/1P5P/5RK1 w - - 0 6

Engine: Shredder 6 Tricky-Tahoma
by Stefan Meyer-Kahlen
10.01 0:02 +8.74++ 1.h3 Qe8 2.axb5 axb5 3.Kg2 Qe7 4.Rf2 Rxe4 5.Rf8+ Qxf8 6.e7+ Rc4 7.Bxc4+ Qf7 8.e8R+ (2.055.749) 797.4
10.01 0:02 +8.74 1.h3 Qc5+ 2.Kg2 Qe7 3.axb5 axb5 4.Rf2 Qe8 5.Rf5 Qa8 6.h4 Rxe4 (2.157.834) 798.3
11.01 0:03 +8.55 1.h3 Qe8 2.axb5 axb5 3.Kh2 Qe7 4.Be3 (2.960.452) 816.6
12.01 0:07 +8.80++ 1.h3 Qe8 2.axb5 axb5 3.Ba2 Rxe4 4.e7+ Rc4 5.Bxc4+ Qf7 6.Rxf7 g5 (5.788.592) 821.4
12.01 0:08 +8.80 1.h3 Qc5+ 2.Kh1 Qe7 3.axb5 axb5 4.Ba2 Qg7 5.Bxc4 bxc4 6.Rf6 (6.621.083) 825.9
12.09 0:17 +8.81++ 1.Kg2 bxa4 2.Bxc4 Qc5 (14.602.647) 844.2
12.09 0:26 +9.16++ 1.Kg2 Qe8 2.axb5 axb5 3.Ba2 Rxe4 4.Rf8+ Qxf8 5.e7+ Rc4 6.Bxc4+ bxc4 7.exf8R+ (22.186.874) 841.7
12.09 0:36 +10.30 1.Kg2 Qe8 2.axb5 axb5 3.Ba2 Qa8 4.h3 Qxe4+ 5.Kg1 Qf5 6.Rxf5 gxf5 7.b4 Rxc3 (31.205.229) 851.6
13.01 0:57 +10.05-- 1.Kg2 Qg7 2.Bxc4 bxc4 3.Bxg7 Kxg7 4.e7 Rg8 5.Rf3 (50.205.908) 868.4
13.01 1:08 +9.55-- 1.Kg2 Qg7 2.Bxc4 bxc4 3.Bxg7 Kxg7 4.e7 Rg8 5.Rf3 g5 (60.266.767) 873.6
13.01 1:16 +9.55 1.Kg2 Qg7 2.Bxc4 bxc4 3.Bxg7 Kxg7 4.Rf7+ Kh6 5.e7 Rb8 6.Kg3 Rxb2 7.e8Q g5 8.Rf2 (67.889.728) 882.0
13.15 1:23 +9.56++ 1.Ba2 bxa4 2.Bxc4 (73.492.745) 881.8
13.15 1:25 +9.91++ 1.Ba2 bxa4 2.Bxc4 Qe8 3.Bxa6 g5 (74.961.986) 879.6
best move: Bb3-a2 time: 1:35.625 min n/s: 877.518 CPU 197.3% nodes: 83.912.731

------------------------
[ENGINE]
Name=Shredder 6 Tricky-Tahoma
Author=Stefan Meyer-Kahlen
Filename=Engine.exe
[OPTIONS]
Queen=25
Queen (Endgame)=99
Rook=50
Knight=125
Pawn=200
Forward Pruning=5
King Safety=25
Center Control=60
Pawn Structure=90
Pawn Structure (Endgame)=95
Bishop Pair=25
Bishop Pair (Endgame)=25
Knowledge=400

Interesting...but how does it fare in real games?

[Kirk]

Probably very erractic. Just a fun exercise. Wonder how many engines have attempted to adjust parameters during a game depending on the current pieces on the board?

[Terry McCracken]

Probably very erractic. Just a fun exercise. Wonder how many engines have attempted to adjust parameters during a game depending on the current pieces on the board?

I think you're on to something, and I think the programmers should give it some thought

[Graham Banks]

Probably very erractic. Just a fun exercise. Wonder how many engines have attempted to adjust parameters during a game depending on the current pieces on the board?

I think you're on to something, and I think the programmers should give it some thought

I've seen it discussed on the Rybka forum at one stage.

[Ovyron]

ProDeo already allows you to use different setting depending on the pieces of the board (And whether the engine is losing or winning), it was called the "multiple engine concept", however, nothing was found that played better than the default settings.