Arpad Rusz wrote:The following study has at least five variations with queen sacrifices which makes it hard for the engines. White wins!
[pgn][Event "StrateGems"]
[Site "?"]
[Date "2015.??.??"]
[Round "?"]
[White "Wieland Bruch (after G .Heathcote)"]
[Black "?"]
[Result "1-0"]
[SetUp "1"]
[FEN "r7/1QpnN1Kp/p3P1b1/Nn1P1p2/3k3p/p4BP1/1rPPp2q/8 w - - 0 0"]
[PlyCount "13"]
1. d6 Nb6 2. dxc7 Nd6 3. Qc6 Ne4 (3... Ndc4 4. Qb5 $1 Rxb5 5. Nec6+ Kc5 6. Nb7#
) 4. Nb7 e1=Q (4... Ke5 5. Qd6+ $1 Nxd6 6. Nc6+ Kxe6 7. Nc5#) (4... Rb5 5. Qc3+
$1 Nxc3 6. Nc6+ Kc4 7. d3#) (4... Qxg3 5. Qd5+ $1 Nxd5 6. Nc6+ Kc4 7. Bxe2+ Qd3
8. Bxd3#) 5. Qc5+ $1 Nxc5 6. Nc6+ Kc4 7. Nd6# 1-0[/pgn]
Probably a good test of your LMR and LMP. I ended up with a PV that looked promising after a lot of FHs in the right direction
43/85 736:37 +M25 1.d6 Nb6 2.dxc7 Kc5 {?!?} 3.Qxa8 Nxa8
4.Nb7+ Kb6 5.c8Q Nbc7 6.Qd8 Qg1
7.Nc8+ Kb5 8.Qd7+ Kb4 9.Qd6+ Ka4
10.Qf4+ Rb4 11.Bc6+ Nb5 12.Bxb5+ axb5
13.Qb8 Qd4+ 14.Kg8 (544.088.060.422) 12310
best move: d5-d6 time: 736:37.484 min n/s: 12.310.425 nodes: 544.088.060.422
Unfortunately, 2... Kc5 is actually only good for postponing the inevitable mate to #13:
After 2...Kc5
[D]r7/1QP1N1Kp/pn2P1b1/Nnk2p2/7p/p4BP1/1rPPp2q/8 w - -
45/42 74:59 +M13 3.Nd5 Nd4 4.Qxa8 Nc8 5.Qxc8 Be8
6.Qxe8 Qxg3+ 7.Kh8 Qe5+ 8.Kxh7 Qxc7+
9.Nxc7 Rb6 10.Qf8+ Rd6 11.Nb7+ Kb6
12.Qxd6+ Nc6 13.Qxc6+ Ka7 14.Nd6 e1Q
15.Qb7+ (32.537.781.398) 7231
So even though the Fail Highs were correct, the PV wasn't. But now I have an update (bugfix) that probably is better, only I have not let it run to that depth yet and is still failing high. But I don't think it will produce the above horrible PV anymore.
r7/1QpnN1Kp/p3P1b1/Nn1P1p2/3k3p/p4BP1/1rPPp2q/8 w - -
Engine: Ancalagon_017 HT (i 6700, 512 MB)
by T. Romstad, M. Costalba, J. Kiiski, G. Linscott
18/37 0:01 -3.95 1.Qxa8 e1Q 2.Nec6+ Kc5 3.Nb7+ Kb6
4.exd7 Rxc2 5.Nd6 Qa1+ 6.d4 Rxc6
7.Qxc6+ Ka5 8.Nb7+ Kb4 9.Qc5+ Kb3
10.d6 cxd6 11.Bd5+ Kb2 12.Qb4+ Kc2
13.d8Q Qxd4+ 14.Qxd4 (18.435.470) 12661
19/37 0:01 -4.26 1.Qxa8 e1Q 2.Nec6+ Kc5 3.Nb7+ Kb6
4.exd7 Rxc2 5.Nd6 Qa1+ 6.d4 Rxc6
7.Qxc6+ Ka5 8.Nb7+ Kb4 9.Qc5+ Kb3
10.d6 Qc3 11.d8Q cxd6 12.Qxc3+ Nxc3
13.Na5+ Ka4 14.Qxd6 (20.229.162) 12643
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23/49 0:24 -6.00-- 1.Qxa8 e1Q (313.599.300) 13040
23/49 0:43 -5.83++ 1.Qxa8 e1Q 2.Nec6+ Kc5 3.Nb7+ Kb6
4.exd7 Rxc2 5.Nd6 Qa1+ 6.d4 Rxc6
7.Qxc6+ Ka5 8.Nb7+ Kb4 9.Qc5+ Kb3
10.Na5+ Ka2 11.d8Q Qxd4+ 12.Qxd4 Nxd4
13.Qxc7 Qb2 14.Qc4+ (559.102.918) 12968
23/49 1:12 -6.05-- 1.Qxa8 e1Q 2.Nec6+ Kc5 3.Nb7+ Kb6
4.exd7 Rxc2 5.Nd6 Qhxd2 6.d8Q Qc3+
7.Kg8 Bf7+ 8.Kxh7 Bg8+ 9.Qxg8 Qxf3
10.Nc8+ Kc5 11.Qf8+ Kc4 12.Qxa6 Qh5+
13.Qh6 (918.149.724) 12737
23/49 1:16 -6.54-- 1.Qxa8 e1Q (975.361.728) 12734
23/49 1:48 -6.14++ 1.d6 {with some search luck, it does not really see this accurately}(1.374.784.984) 12661
23/49 1:58 -5.35++ 1.d6 (1.490.495.241) 12554
23/49 2:01 -4.33++ 1.d6 (1.517.254.204) 12538
23/49 2:21 -3.04++ 1.d6 (1.755.202.437) 12433
23/49 2:24 -1.41++ 1.d6 (1.792.277.688) 12406
23/49 2:33 -1.35 1.d6 Nb6 2.dxc7 Nd6 3.Qc6 Ndc4
4.Qxa8 Nxd2 5.Qxa6 Ke3 6.Qd3+ Kf2
7.Qxe2+ Kg1 8.Qd1+ Nf1 9.Be2 Qxg3
10.Qxf1+ Kh2 11.Kf8 Rxc2 12.Nc4 a2
13.Nxb6 Rxc7 14.Nbd5 (1.902.015.335) 12375
24/49 2:54 -1.27++ 1.d6 (2.142.665.010) 12291
24/49 2:54 -1.20++ 1.d6 (2.145.487.040) 12291
24/49 3:13 -1.27-- 1.d6 Nb6 2.dxc7 (2.379.639.069) 12307
24/49 3:20 -1.43-- 1.d6 Nb6 (2.477.691.453) 12360
24/49 3:20 -1.64-- 1.d6 Nb6 (2.482.080.729) 12361
24/49 3:21 -1.92-- 1.d6 Nb6 (2.488.736.949) 12364
24/49 3:22 -2.29-- 1.d6 Nb6 (2.509.873.025) 12375
24/49 3:26 -2.77-- 1.d6 Nb6 (2.563.570.775) 12387
24/49 3:39 -3.00 1.d6 Nb6 2.dxc7 Nd6 3.Qc6 Ndc4
4.Qxa8 Nxd2 5.Qxa6 Ke3 6.Qd3+ Kf2
7.Qxe2+ Kg1 8.Qd1+ Nf1 9.Nxg6 Qxc2
10.Qd4+ Qf2 11.Qxf2+ Kxf2 12.e7 a2
13.e8Q a1Q 14.Nc4 (2.737.811.206) 12473
25/49 4:18 -3.08-- 1.d6 Nb6 2.dxc7 (3.274.709.993) 12660
25/49 4:41 -3.15-- 1.d6 Nb6 2.dxc7 (3.578.547.474) 12713
25/49 4:56 -3.26-- 1.d6 Nb6 (3.802.656.566) 12816
25/54 5:11 -3.41-- 1.d6 Nb6 (4.002.060.876) 12867
25/54 5:32 -3.51 1.d6 Nb6 2.dxc7 Nd6 3.Qc6 Ndc4
4.Qxa8 Nxd2 5.Qxa6 Ke3 6.Qd3+ Kf2
7.Qxe2+ Kg1 8.Qd1+ Nf1 9.Nxg6 Qxc2
10.Qd4+ Qf2 11.Qxf2+ Kxf2 12.e7 a2
13.Nc4 a1Q 14.e8Q (4.309.598.054) 12942
26/54 5:41 -3.58-- 1.d6 Nb6 2.dxc7 (4.430.787.219) 12960
26/54 6:15 -3.65-- 1.d6 Nb6 2.dxc7 Nd6 3.Qc6 Ndc4
4.Qxa8 Nxd2 5.Qxa6 Ke3 6.Qd3+ Kf2
7.Qxe2+ Kg1 8.Qd1+ Nf1 9.Nxg6 Qxc2
10.Qd4+ Qf2 11.Qxf2+ Kxf2 12.Nc4 hxg6
13.e7 a2 14.Kxg6 (4.876.992.492) 12973
26/63 6:23 -3.76-- 1.d6 Nb6 (4.985.425.676) 12983
26/63 6:30 -3.91-- 1.d6 Nb6 (5.071.578.930) 12980
26/63 6:30 -3.78++ 1.d6 (5.073.116.730) 12980
26/63 6:31 -3.95-- 1.d6 Nb6 2.dxc7 (5.083.546.317) 12979
26/63 6:40 -4.28 1.d6 Nb6 2.dxc7 Nd6 3.Qc6 Ndc4
4.Qxa8 Nxd2 5.Qxa6 Ke3 6.Qd3+ Kf2
7.Qxe2+ Kg1 8.Qd1+ Nf1 9.Nxg6 Qxc2
10.e7 Qxd1 11.Bxd1 a2 12.e8Q a1Q
13.Qe5 hxg6 14.Qd4+ (5.203.313.361) 12980
27/63 7:46 -4.21++ 1.d6 Nb6 2.dxc7 Nd6 3.Qc6 Ndc4
4.Qxa8 Nxd2 5.Qxa6 Ke3 6.Qd3+ Kf2
7.Qxe2+ Kg1 8.Qd1+ Nf1 9.Nxg6 Qxc2
10.e7 Qxd1 11.Bxd1 a2 12.Nf4 a1Q
13.e8Q Qxd1 14.Qe5 (6.052.789.655) 12967
27/63 7:47 -4.14++ 1.d6 (6.058.222.728) 12966
27/63 7:50 -4.03++ 1.d6 (6.098.446.492) 12960
27/63 7:56 -4.12-- 1.d6 Nb6 (6.176.885.571) 12957
27/63 8:36 -4.33-- 1.d6 Nb6 2.dxc7 Nd6 3.Qc6 Ndc4
4.Qxa8 Nxd2 5.Qxa6 Ke3 6.Qd3+ Kf2
7.Qxe2+ Kg1 8.Qd1+ Nf1 9.Nxg6 Qxc2
10.Kxh7 Qxd1 11.Bxd1 a2 12.e7 a1Q
13.e8Q (6.708.561.303) 12997
27/63 8:42 -4.42 1.d6 Nb6 2.dxc7 Nd6 3.Qc6 Ndc4
4.Qxa8 Nxd2 5.Qxa6 Ke3 6.Qd3+ Kf2
7.Qxe2+ Kg1 8.Qe1+ Nf1 9.Nxg6 Rxc2
10.Nc6 Qxg3 11.Qxg3+ hxg3 12.e7 a2
13.e8Q a1Q+ 14.Nge5 (6.788.845.974) 12988
28/63 9:10 -4.35++ 1.d6 (7.147.665.215) 12981
28/63 9:30 -4.27++ 1.d6 (7.387.473.927) 12959
28/63 9:53 -4.35-- 1.d6 Nb6 (7.686.575.005) 12956
28/63 10:04 -4.25++ 1.d6 (7.828.482.851) 12954
28/63 10:13 -4.04++ 1.d6 (7.940.194.496) 12951
28/63 10:54 -4.21-- 1.d6 Nb6 2.dxc7 (8.472.557.825) 12948
28/63 11:15 -3.98++ 1.d6 (8.749.484.413) 12948
28/63 11:38 -4.28-- 1.d6 Nb6 (9.049.833.705) 12949
28/63 13:31 -4.91-- 1.d6 Nb6 2.dxc7 (10.555.255.073) 13000
28/63 13:43 -4.82 1.d6 Nb6 2.dxc7 Nd6 3.Qc6 Ndc4
4.Qxa8 Nxd2 5.Qxa6 Ke3 6.Qd3+ Kf2
7.Qxe2+ Kg1 8.Qd1+ Nf1 9.Nxg6 Qxc2
10.e7 Qxd1 11.Bxd1 a2 12.e8Q a1Q
13.Qe5 hxg6 14.gxh4 (10.707.676.179) 13003
29/63 14:06 -4.89-- 1.d6 Nb6 2.dxc7 (11.001.163.187) 13002
29/63 14:35 -4.96-- 1.d6 Nb6 (11.396.088.671) 13014
29/63 16:54 -5.07-- 1.d6 Nb6 2.dxc7 (13.253.374.387) 13062
29/63 18:33 -5.22-- 1.d6 Nb6 2.dxc7 (14.554.512.225) 13075
29/63 18:33 -5.10++ 1.d6 (14.564.969.573) 13075
29/63 18:34 -4.82++ 1.d6 (14.571.647.015) 13074
29/63 18:36 -4.45++ 1.d6 (14.593.890.605) 13073
29/63 18:39 -4.74-- 1.d6 Nb6 (14.639.246.222) 13073
29/63 18:51 -4.92 1.d6 Nb6 2.dxc7 Nd6 3.Qc6 Ndc4
4.Qxa8 Nxd2 5.Qxa6 Ke3 6.Qd3+ Kf2
7.Qxe2+ Kg1 8.Qd1+ Nf1 9.Nxg6 Qxc2
10.e7 Qxd1 11.Bxd1 a2 12.e8Q a1Q
13.Qe5 hxg6 14.gxh4 (14.790.096.663) 13068
30/63 19:22 -5.00-- 1.d6 Nb6 (15.191.837.271) 13062
30/63 20:01 -4.92++ 1.d6 (15.693.005.303) 13062
30/63 20:50 -5.00-- 1.d6 Nb6 2.dxc7 (16.352.309.874) 13080
30/63 21:44 -5.15-- 1.d6 Nb6 (17.096.859.050) 13110
30/63 22:28 -5.02++ 1.d6 (17.710.912.745) 13133
30/63 22:43 -4.74++ 1.d6 (17.898.942.034) 13126
30/63 22:46 -4.37++ 1.d6 (17.933.433.357) 13124
30/63 23:09 -3.89++ 1.d6 (18.208.616.275) 13104
30/63 23:41 -4.27-- 1.d6 Nb6 2.dxc7 (18.615.432.469) 13095
30/67 24:23 -5.07-- 1.d6 Nb6 (19.182.717.895) 13106
30/70 29:28 -5.19 1.d6 Nb6 2.dxc7 Nd6 3.Qc6 Ndc4
4.Qxa8 Nxd2 5.Qd8+ Ke3 6.Qd3+ Kf2
7.Qxe2+ Kg1 8.Qe1+ Nf1 9.Nxg6 Rxc2
10.Nc6 Qxg3 11.Qxg3+ hxg3 12.e7 a2
13.e8Q a1Q+ 14.Nge5 (23.188.534.889) 13114
31/70 30:04 -5.26-- 1.d6 Nb6 (23.676.185.596) 13123
31/70 30:45 -5.33-- 1.d6 Nb6 (24.250.348.471) 13137
31/70 32:34 -5.44-- 1.d6 Nb6 (25.723.741.106) 13160
31/70 33:50 -5.60-- 1.d6 Nb6 (26.715.889.883) 13157
31/70 34:10 -5.47++ 1.d6 (26.977.072.723) 13156
31/70 35:17 -5.19++ 1.d6 (27.864.330.040) 13159
31/70 36:23 -5.41-- 1.d6 Nb6 (28.720.314.821) 13152
31/70 36:47 -5.52 1.d6 Nb6 2.dxc7 Nd6 3.Qc6 Ndc4
4.Qxa8 Nxd2 5.Qxa6 Ke3 6.Qd3+ Kf2
7.Qxe2+ Kg1 8.Qd1+ Nf1 9.Nxg6 Qxc2
10.e7 Qxd1 11.Bxd1 a2 12.e8Q a1Q
13.Qe5 hxg6 14.gxh4 (29.045.605.941) 13155
32/70 37:30 -5.45++ 1.d6 (29.618.718.369) 13159
32/70 43:38 -5.52-- 1.d6 Nb6 2.dxc7 (34.414.879.972) 13143
32/70 45:08 -5.63-- 1.d6 Nb6 (35.639.637.892) 13156
32/70 48:32 -5.54++ 1.d6 Nb6 2.dxc7 Nd6 3.Qc6 Ndc4
4.Qxa8 Nxd2 5.Qd8+ Ke3 6.Qd3+ Kf2
7.Qxe2+ Kg1 8.Qe3+ Qf2 9.Qxa3 Rxc2
10.Qa1+ Kh2 11.Bc6 Bh5 12.gxh4 Qg3+
13.Kf8 Ne4 14.c8Q (38.262.260.594) 13139
32/70 48:55 -5.33++ 1.d6 (38.537.996.531) 13130
32/70 49:11 -5.04++ 1.d6 (38.732.466.458) 13122
32/70 49:16 -4.67++ 1.d6 (38.792.383.286) 13120
32/70 49:25 -4.19++ 1.d6 (38.895.207.362) 13117
32/70 49:36 -3.56++ 1.d6 (39.027.984.247) 13112
32/70 49:58 -2.77++ 1.d6 (39.291.581.470) 13103
32/70 50:41 -1.75++ 1.d6 (39.786.288.676) 13082
32/70 55:38 -0.46++ 1.d6 (43.219.947.021) 12945
32/70 57:33 0.00 1.d6 Nb6 2.dxc7 Nd6 3.Qc6 Ndc4 4.Qb5 {!} Rxc2
5.Qb3 Ke5 6.Nxc4+ Rxc4 7.Qe3+ Re4
8.Bxe4 e1Q 9.Nxg6+ hxg6 10.d4+ Kd6
11.Qxa3+ Kxe6 12.Qb3+ Kd7 13.Qf7+ Kd6
14.Qf6+ (44.670.686.455) 12934
33/70 65:40 +0.07++ 1.d6 (50.489.047.649) 12812
33/70 67:11 +0.14++ 1.d6 (51.580.047.424) 12794
33/70 68:37 +0.25++ 1.d6 (52.585.405.992) 12770
33/70 68:49 +0.40++ 1.d6 (52.718.243.267) 12766
33/70 69:07 +0.61++ 1.d6 (52.922.603.888) 12760
33/70 69:15 +0.89++ 1.d6 (53.014.753.023) 12757
33/70 71:53 +1.27++ 1.d6 (54.847.658.558) 12716
33/70 72:38 +1.75++ 1.d6 (55.381.626.862) 12707
33/70 76:12 +2.37++ 1.d6 (57.985.356.820) 12681
33/70 79:49 +3.17++ 1.d6 Nb6 2.dxc7 Nd6 3.Qc6 Ne8+ 4.Kh6 hxg3+
5.Kg5 Qh4+ 6.Kxh4 Ke5 7.Bxe2 g2
8.Qxg2 a2 9.Nac6+ Kxe6 10.Nxg6 hxg6
11.Qxg6+ Kd7 12.Qxf5+ Kxc6 13.Bf3+ Kxc7
14.Qc5+ (60.605.552.321) 12654
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38/82 222:06 +8.19 1.d6 Nb6 2.dxc7 Nd6 3.Qc6 Ne8+ 4.Kh6 hxg3+
5.Kg5 Qh4+ 6.Kxh4 Ke5 7.Bxe2 g2
8.Qxg2 a2 9.Nc4+ Kxe6 10.Nxg6 a1Q
11.Qxa8 Qe1+ 12.Kh3 Nxa8 13.c8Q+ Kf6
14.Qd8+ (176.575.463.687) 13249