This type of position is one where Rebel excels at so probably the Rebel-type extensions will help here.
Good old Pro Deo 1.5, with Judith Polgar settings: 0.4 seconds on Athlon 2009MHZ, 192Mb.
Code: Select all
00:00:00.1 -1,10 1 7 Nxd5 cxd5
00:00:00.1 -1,03 1 15 Bf6 gxf6 exf6
00:00:00.1 0,52 1 17 Rae1
00:00:00.1 0,68 1 19 Rad1
00:00:00.1 0,25 2 159 Rad1 Nd7
00:00:00.1 0,50 2 266 f4 Nd7
00:00:00.1 0,45 3 909 f4 Bf5 Rac1
00:00:00.2 0,51 3 2039 Ne2 Nd7 f4
00:00:00.2 0,41 4 4269 Ne2 Nd7 f4 c5
00:00:00.2 0,41 4 15423 e6
00:00:00.2 0,87 4 16190 e6 Qxe6 Rae1
00:00:00.2 0,87 4 17011 Bf6
00:00:00.2 1,29 4 17563 Bf6 Rg8 Nxd5 gxf6 Qxg8+ Kxg8 Nxf6+ Kf8 Nxe8 Kxe8
00:00:00.2 1,29 5 20550 Bf6 Rg8 Nxd5 gxf6 Qxg8+ Kxg8 Nxf6+ Kf8 Nxe8 Kxe8
00:00:00.2 1,29 6 34290 Bf6 Rg8 Nxd5 gxf6 Qxg8+ Kxg8 Nxf6+ Kf8 Nxe8 Kxe8
00:00:00.2 1,29 7 66483 Bf6 Rg8 Nxd5 gxf6 Qxg8+ Kxg8 Nxf6+ Kf8 Nxe8 Kxe8
00:00:00.3 1,51 8 151492 Bf6 Rg8 Nxd5 gxf6 Qxg8+ Kxg8 Nxf6+ Kf8 Nxe8 Kxe8 f4 Nd7
00:00:00.4 1,51 8 220722 Nxd5
00:00:00.5 1,91 8 327151 Nxd5 cxd5 Bf6 gxf6 exf6 Qd8 Qg7+ Ke8 Qxh8+ Kd7 Qxd8+ Kxd8 Rae1
00:00:00.7 2,05 9 601044 Nxd5 cxd5 Bf6 gxf6 exf6 Qd8 Qg7+ Ke8 Qxh8+ Kd7 Qg7 Kc7 Qxf7+ Nd7 Rae1
00:00:01.5 2,05 10 1730384 Nxd5 cxd5 Bf6 gxf6 exf6 Qd8 Qg7+ Ke8 Qxh8+ Kd7 Qg7 Kc7 Qxf7+ Nd7 Rae1
00:00:05.3 2,32 11 6646746 Nxd5 cxd5 Bf6 gxf6 exf6 Qd8 Qg7+ Ke8 Qxh8+ Kd7 Qg7 Kd6 Qxf7 Nd7 Rae1 Kc7 Qxh7 Qxf6
00:00:12.7 2,32 12 16418905 Nxd5 cxd5 Bf6 gxf6 exf6 Qd8 Qg7+ Ke8 Qxh8+ Kd7 Qg7 Kd6 Qxf7 Nd7 Rae1 Kc7 Qxh7 Qxf6
00:00:40.2 2,34 13 53220164 Nxd5 cxd5 Bf6 g6 Qe3 Kg8 Qh6 Qf8 Qxf8+ Kxf8 Bxh8 Nc6 Rfd1 Kg8
Number of plies does not say very much, for instance look at the disastrous result from latest Blueberry: 5 plies and 2 minutes 22 seconds.
[D]rnb1qk1r/pp3ppp/2p5/3pP1B1/8/2N3Q1/PPP2PPP/R4RK1 w - -
Engine: Blueberry Beta 4 DM70 Build
416 (Athlon 2009 MHz, 128 MB)
by F. Letouzey, T. Gaksch, E. de Groot
1/01 0:00 +3.90 1.Rab1 (3)
1/01 0:00 +4.14 1.Rad1 (7)
1/01 0:00 +5.18 1.Rae1 (9)
2/16 0:00 +3.41 1.Rae1 Kg8 2.Bf6 Qf8 (27.406)
3/33 0:01 +3.94 1.Rae1 Bf5 2.Na4 (865.101) 607
4/37 0:02 +3.32 1.Rae1 Bf5 2.Qf4 Bxc2 3.Re2 Nd7
4.Rxc2 Qxe5 5.Qb4+ Kg8 6.Qxb7 (1.182.611) 590
5/49 0:17 +2.38 1.Rae1 Bf5 2.Qf3 Bg6 3.e6 Kg8 4.Qg4 fxe6
5.Rxe6 (10.440.176) 596
5/49 2:21 +3.23 1.Nxd5 cxd5 2.Bf6 gxf6 3.exf6 Qc6
4.Qg7+ Ke8 5.Qxh8+ Kd7 6.Rae1 Kc7
7.Re7+ Bd7 8.Rxf7 Qxc2 9.Rxd7+ Nxd7
10.Qxa8 Nxf6 11.Qxa7 Qxb2 12.Qc5+ Kb8
13.Qd6+ Ka7 (79.688.596) 563
5/49 2:22 +3.23 1.Nxd5 cxd5 2.Bf6 gxf6 3.exf6 Qc6
4.Qg7+ Ke8 5.Qxh8+ Kd7 6.Rae1 Kc7
7.Re7+ Bd7 8.Rxf7 Qxc2 9.Rxd7+ Nxd7
10.Qxa8 Nxf6 11.Re1 Qxb2 12.f3 Nd7
13.Qxa7 (80.454.506) 564
5/58 2:40 +3.23 1.Nxd5 cxd5 2.Bf6 gxf6 3.exf6 Qc6
4.Qg7+ Ke8 5.Qxh8+ Kd7 6.Rae1 Kc7
7.Re7+ Bd7 8.Rxf7 Qxc2 9.Rxd7+ (92.753.900) 576
6/58 2:44 +3.22 1.Nxd5 cxd5 2.Bf6 gxf6 3.exf6 Qc6
4.Qg7+ Ke8 5.Qxh8+ Kd7 6.Rad1 Kc7
7.Qxh7 Qxf6 8.Rxd5 Qxb2 9.Qxf7+ Bd7 (95.144.218) 577
7/58 3:52 +3.22 1.Nxd5 cxd5 2.Bf6 gxf6 3.exf6 Qc6
4.Qg7+ Ke8 5.Qxh8+ Kd7 6.Rad1 Kc7
7.Qxh7 Qxf6 8.Rxd5 Qxb2 9.Qxf7+ Bd7 (133.102.056) 573
8/58 9:48 +3.58 1.Nxd5 cxd5 2.Bf6 gxf6 3.exf6 Qc6
4.Qg7+ Ke8 5.Qxh8+ Kd7 6.c4 d4
7.Rad1 Qc5 8.Rfe1 Qxc4 9.Re7+ Kd6
10.Qd8+ Nd7 11.Rxd7+ Bxd7 12.Qxa8 (330.367.491) 561
9/58 12:35 +3.23 1.Nxd5 cxd5 2.Bf6 gxf6 3.exf6 Qc6
4.Qg7+ Ke8 5.Qxh8+ Kd7 6.Rae1 Kc7
7.Re7+ Bd7 8.Rxf7 Qxc2 9.Rxd7+ Nxd7
10.Qxa8 Nxf6 11.Qxa7 Qxb2 12.Qc5+ Kb8
13.Qd6+ Ka7 (424.281.511) 561
10/58 44:55 +3.23 1.Nxd5 cxd5 2.Bf6 gxf6 3.exf6 Qc6
4.Qg7+ Ke8 5.Qxh8+ Kd7 6.Rae1 Kc7
7.Re7+ Bd7 8.Rxf7 Qxc2 9.Rxd7+ Nxd7
10.Qxa8 Nxf6 11.Qxa7 Qxb2 12.Qc5+ Kb8
13.Qd6+ Ka7 (1.520.591.695) 564
11/59 106:38 +3.20 1.Nxd5 cxd5 2.Bf6 g6 3.Bxh8 Kg8
4.Bf6 Bf5 5.Rad1 Nd7 6.Rxd5 Rc8
7.Qh4 Rc6 8.Rd4 h5 9.Ra4 Nxf6
10.exf6 Rxc2 11.Rxa7 Rxb2 (3.604.622.019) 563
best move: Nc3xd5 time: 160:01.563 min n/s: 561.307 CPU 100.0% n/s(1CPU): 561.307 nodes: 5.389.340.000
But, not all is lost, I was a bit desperate after above result with build 416 but today I rewound 41 versions and got a better result with build 375. All later versions extend the PV with null window searches, but as Fruit shows "Keep It Simple Stupid" still works best here
rnb1qk1r/pp3ppp/2p5/3pP1B1/8/2N3Q1/PPP2PPP/R4RK1 w - -
Engine: Blueberry Beta 4 DM70 Build
375 (Athlon 2009 MHz, 128 MB)
by F. Letouzey, T. Gaksch, E. de Groot
1/01 0:00 +3.90 1.Rab1 (3)
1/01 0:00 +4.14 1.Rad1 (7)
1/01 0:00 +5.18 1.Rae1 (9)
2/17 0:00 +2.93 1.Rae1 h6 2.Be3 Kg8 3.Bd4 Bf5 (8.349)
3/30 0:00 +2.63 1.Rae1 Bf5 2.Qf4 Bxc2 3.Qb4+ Kg8
4.Qxb7 Nd7 5.f4 (273.680)
3/34 0:01 +3.14 1.Nxd5 cxd5 2.Bf6 gxf6 3.exf6 Qc6
4.Qg7+ Ke8 5.Qxh8+ Kd7 6.Qxh7 Qxf6
7.Rad1 Kc6 (860.233) 550
3/35 0:01 +3.14 1.Nxd5 cxd5 2.Bf6 gxf6 3.exf6 Qc6
4.Qg7+ Ke8 5.Qxh8+ Kd7 6.Qg7 Kc7
7.Rfe1 Qxc2 8.Qg3+ Kb6 9.Qd6+ Ka5
10.Qxd5+ Ka6 (987.197) 550
3/44 0:02 +3.14 1.Nxd5 cxd5 2.Bf6 gxf6 3.exf6 Qc6
4.Qg7+ Ke8 5.Qxh8+ Kd7 6.Rae1 Kc7
7.Re7+ Nd7 8.Qg7 Qxc2 9.Qg3+ Kb6
10.Qd6+ Ka5 11.Qxd5+ Nc5 12.Rxf7 (1.748.424) 575
4/44 0:02 +2.91 1.Nxd5 cxd5 2.Bf6 gxf6 3.exf6 Qc6
4.Qg7+ Ke8 5.Qxh8+ Kd7 6.Rfe1 Qxc2
7.Re7+ Kd6 8.Qd8+ Bd7 9.Rxd7+ Nxd7
10.Qxa8 (1.830.466) 621
5/44 0:05 +3.30 1.Nxd5 cxd5 2.Bf6 gxf6 3.exf6 Qc6
4.Qg7+ Ke8 5.Rae1+ Kd8 6.Qxh8+ Kc7
7.Re7+ Kb6 (3.252.212) 612
6/44 0:11 +3.22 1.Nxd5 cxd5 2.Bf6 gxf6 3.exf6 Qc6
4.Qg7+ Ke8 5.Qxh8+ Kd7 6.Rad1 Kc7
7.Qxh7 Qxf6 8.Rxd5 Qxb2 9.Qxf7+ Bd7 (6.924.363) 622
7/46 0:37 +3.22 1.Nxd5 cxd5 2.Bf6 gxf6 3.exf6 Qc6
4.Qg7+ Ke8 5.Qxh8+ Kd7 6.Rad1 Kc7
7.Qxh7 Qxf6 8.Rxd5 Qxb2 9.Qxf7+ Bd7 (23.165.913) 622
8/46 1:55 +3.34 1.Nxd5 cxd5 2.Bf6 gxf6 3.exf6 Qd8
4.Qg7+ Ke8 5.Qxh8+ Kd7 6.Qg7 Kd6
7.Qxf7 Nd7 8.Rad1 Nxf6 9.Rfe1 Kc6 (71.405.485) 618
9/46 3:16 +3.47 1.Nxd5 cxd5 2.Bf6 gxf6 3.exf6 Qc6
4.Qg7+ Ke8 5.Qxh8+ Kd7 6.Qg7 Kd6
7.Qg3+ Kd7 8.Rfe1 (120.593.806) 615
best move: Nc3xd5 time: 3:26.156 min n/s: 614.810 CPU 100.0% n/s(1CPU): 614.810 nodes: 126.670.000
Eelco