[d]8/1p3pk1/1q1P1bp1/4P3/n1p1P3/P5P1/1PBQ2K1/8 b - - 0 50
With aspiration enabled, it takes 7 seconds to find the best move, at ply 17.
With aspiration disabled, it takes 0 seconds, at ply 10!
Are there some known issues with aspiration windows and other search techniques? The cpw contains a page about PVS and AW, but if I disable PVS, the problem is still there.
The output while analyzing is below (chess22k-ex has AW disabled).
Very strange that the score with AW enabled goes up again at ply 11...
Code: Select all
chess22k:
1/6 00:00 102 4k +1,03 Bf6xe5
2/6 00:00 284 3k +1,03 Bf6xe5 Bc2xa4
3/6 00:00 526 5k +1,03 Bf6xe5 Bc2xa4 Qb6xd6
4/7 00:00 878 7k +1,03 Bf6xe5 Bc2xa4 Qb6xd6 Qd2xd6
5/10- 00:00 3k 20k +0,83 Bf6xe5 d6-d7 Kg7-g8 d7-d8Q+ Qb6xd8 Qd2xd8+
5/10- 00:00 3k 22k +0,63 Bf6xe5 d6-d7 Kg7-g8 d7-d8Q+ Qb6xd8 Qd2xd8+
5/10 00:00 4k 26k +0,59 Bf6xe5 d6-d7 c4-c3 b2xc3 Be5xc3
6/11 00:00 6k 31k +0,59 Bf6xe5 d6-d7 c4-c3 b2xc3 Be5xc3 d7-d8Q
7/12 00:00 10k 48k +0,59 Bf6xe5 d6-d7 c4-c3 b2xc3 Be5xc3 d7-d8Q Bc3xd2
8/13- 00:00 15k 72k +0,39 Bf6xe5 d6-d7 c4-c3 b2xc3 Be5xc3 Qd2-d5 f7-f6 d7-d8Q
8/13- 00:00 19k 87k +0,19 Bf6xe5 d6-d7 c4-c3 b2xc3 Be5xc3 Qd2-d5 f7-f6 d7-d8Q
8/13- 00:00 34k 130k -1,23 Bf6xe5 d6-d7 c4-c3 b2xc3 Be5xc3 Qd2-d5 f7-f6 d7-d8Q
8/14 00:00 42k 139k -1,40 Bf6xe5 d6-d7 c4-c3 b2xc3 Be5xc3 Qd2-d5 Bc3-f6 Bc2xa4
9/15 00:00 66k 160k -1,55 Bf6xe5 d6-d7 c4-c3 b2xc3 Be5xc3 Qd2-d5 Bc3-f6 Bc2xa4 Qb6-b2+
10/17+ 00:00 114k 216k -1,35 Bf6-g5 Qd2xg5 Na4-c5 Qg5-f6+ Kg7-g8 Qf6-f1 Qb6xb2 Qf1xc4 Qb2xe5
10/17 00:00 122k 227k -1,33 Bf6-g5 Qd2xg5 Na4-c5 Qg5-f6+ Kg7-g8 Qf6-f1 Qb6xb2 Qf1xc4 Qb2xe5
11/20+ 00:00 187k 282k -1,03 Bf6xe5 d6-d7 Na4-c5 Qd2-d5 Qb6xb2 d7-d8Q Qb2xc2+ Kg2-h3 Qc2-c3
11/20+ 00:00 197k 295k -0,83 Bf6xe5 d6-d7 Na4-c5 Qd2-d5 Qb6xb2 d7-d8Q Qb2xc2+ Kg2-h3 Qc2-c3
11/20+ 00:00 220k 306k -0,08 Bf6xe5 d6-d7 Na4-c5 Qd2-d5 Qb6xb2 d7-d8Q Qb2xc2+ Kg2-h3 Qc2-c3
11/20+ 00:00 238k 325k +0,59 Bf6xe5 d6-d7 Na4-c5 Qd2-d5 Qb6xb2 d7-d8Q Qb2xc2+ Kg2-h3 Nc5-d3
11/20 00:00 324k 381k +1,12 Bf6xe5 Bc2xa4 Be5xd6 Qd2-c3+ f7-f6 Ba4-c2 Qb6-c6 Qc3-d2 Qc6-c7
12/23 00:00 471k 476k +0,88 Bf6xe5 Bc2xa4 Be5xd6 Qd2-c3+ f7-f6 Ba4-e8 g6-g5 Qc3-d2 Qb6-c5
13/25- 00:01 562k 539k +0,68 Bf6xe5 Bc2xa4 Be5xd6 Qd2-c3+ f7-f6 Ba4-e8 g6-g5 Qc3xc4 Qb6xb2+
13/25 00:01 740k 624k +0,53 Bf6xe5 Bc2xa4 Be5xd6 Qd2-c3+ f7-f6 Ba4-e8 Qb6-d8 Be8-b5 Bd6-e5
14/27+ 00:01 924k 705k +0,83 Bf6xe5 Bc2xa4 Be5xd6 Qd2-c3+ f7-f6 Ba4-e8 Qb6-c5 Qc3-d2 Qc5-e5
14/27+ 00:01 1.112k 779k +1,03 Bf6xe5 Bc2xa4 Be5xd6 Qd2-c3+ f7-f6 Ba4-e8 Qb6-c5 Qc3-d2 Qc5-e5
14/27 00:01 1.527k 902k +1,14 Bf6xe5 Bc2xa4 Be5xd6 Qd2-c3+ f7-f6 b2-b3 c4xb3 Ba4xb3 Qb6-a6
15/29 00:01 1.890k 985k +1,11 Bf6xe5 Bc2xa4 Be5xd6 Qd2-c3+ f7-f6 b2-b3 c4xb3 Ba4xb3 Qb6-a6
16/30 00:02 2.576k 1.092k +1,07 Bf6xe5 Bc2xa4 Be5xd6 Qd2-c3+ f7-f6 b2-b3 c4xb3 Ba4xb3 Qb6-a6
17/32- 00:02 3.295k 1.183k +0,87 Bf6xe5 Bc2xa4 Be5xd6 Qd2-c3+ f7-f6 b2-b3 c4xb3 Qc3-c8 b3-b2
17/34- 00:03 4.619k 1.267k +0,67 Bf6xe5 d6-d7 Na4-c5 d7-d8Q Qb6xd8 Qd2xd8 Be5xb2 Kg2-f3 Nc5-d3
17/34- 00:04 6.687k 1.345k -0,75 Bf6xe5 d6-d7 Na4-c5 d7-d8Q Qb6xd8 Qd2xd8 Be5xb2 Kg2-f3 Nc5-d3
17/34 00:07 11.152k 1.423k -1,31 Bf6-g5 Qd2xg5 Na4-c5 Qg5-c1 Nc5-e6 Bc2-b1 Qb6-d4 Qc1-c3 Qd4-d1
18/34 00:08 12.299k 1.438k -1,31 Bf6-g5 Qd2xg5 Na4-c5 Qg5-c1 Nc5-e6 Bc2-b1 Qb6-d4 Qc1-c3 Qd4-d1
chess22k-ex:
1/6 00:00 102 4k +1,03 Bf6xe5
2/6 00:00 284 2k +1,03 Bf6xe5 Bc2xa4
3/6 00:00 526 3k +1,03 Bf6xe5 Bc2xa4 Qb6xd6
4/7 00:00 878 5k +1,03 Bf6xe5 Bc2xa4 Qb6xd6 Qd2xd6
5/11 00:00 4k 17k +0,59 Bf6xe5 d6-d7 c4-c3 b2xc3 Be5xc3
6/11 00:00 6k 20k +0,59 Bf6xe5 d6-d7 c4-c3 b2xc3 Be5xc3 d7-d8Q
7/12 00:00 10k 25k +0,59 Bf6xe5 d6-d7 c4-c3 b2xc3 Be5xc3 d7-d8Q Bc3xd2
8/16 00:00 27k 45k -1,40 Bf6xe5 d6-d7 c4-c3 b2xc3 Be5xc3 Qd2-d5 Bc3-f6 Bc2xa4
9/16 00:00 53k 69k -1,55 Bf6xe5 d6-d7 c4-c3 b2xc3 Be5xc3 Qd2-d5 Bc3-f6 Bc2xa4 Qb6-b2+
10/17 00:00 105k 114k -1,33 Bf6-g5 Qd2xg5 Na4-c5 Qg5-f6+ Kg7-g8 Qf6-f1 Qb6xb2 Qf1xc4 Qb2xe5
11/19 00:01 171k 167k -1,21 Bf6-g5 Qd2xg5 Na4-c5 Qg5-f6+ Kg7-g8 e5-e6 Nc5xe6 d6-d7 Qb6-d6
12/26 00:01 288k 254k -0,87 Bf6-g5 Qd2xg5 Na4-c5 Qg5-f6+ Kg7-g8 Qf6-f1 Qb6xb2 Qf1xc4 Qb2xe5
13/26 00:01 542k 414k -0,91 Bf6-g5 Qd2xg5 Na4-c5 Qg5-f6+ Kg7-g8 e5-e6 Nc5xe6 d6-d7 Qb6-d6
14/26 00:01 859k 571k -1,16 Bf6-g5 Qd2xg5 Na4-c5 Qg5-c1 Nc5-d7 Bc2-a4 Nd7xe5 Qc1-d2 f7-f6
15/28 00:01 1.626k 821k -1,29 Bf6-g5 Qd2xg5 Na4-c5 Qg5-c1 Nc5-d7 Bc2-a4 Nd7xe5 Qc1-d2 f7-f6
16/30 00:02 2.743k 998k -1,34 Bf6-g5 Qd2xg5 Na4-c5 Qg5-c1 Nc5-d7 Bc2-a4 Nd7xe5 Qc1-d2 f7-f6
17/30 00:03 4.417k 1.142k -1,10 Bf6-g5 Qd2xg5 Na4-c5 Qg5-c1 Kg7-g8 Bc2-b1 Nc5-d7 e5-e6 f7xe6
18/32 00:05 6.904k 1.286k -1,19 Bf6-g5 Qd2xg5 Na4-c5 Qg5-c1 Nc5-d7 Bc2-a4 Nd7xe5 Qc1-d2 c4-c3
19/35 00:06 9.313k 1.364k -1,12 Bf6-g5 Qd2xg5 Na4-c5 Qg5-c1 Nc5-d7 Bc2-a4 Nd7xe5 Qc1-d2 c4-c3
20/38 00:08 12.165k 1.422k -1,12 Bf6-g5 Qd2xg5 Na4-c5 Qg5-c1 Nc5-d7 Bc2-a4 Nd7xe5 Qc1-d2 c4-c3