Just noticed a strange behavior at a test position from
this thread
[d]1r3rk1/3bbppp/1qn2P2/p2pP1P1/3P4/2PB1N2/6K1/qNBQ1R2 w - - bm Bxh7+;
With 128 MB hash and 1 thread on a mac.
without tbs: Crystal 1.1 finds Bxh7+ after fantastic 27" and stays with it
0.00: -10.43/3 1.fxe7 Nxe7 2.Bd2
0.00: -10.57/4 1.fxe7 Nxe7 2.Bd2 Nf5
0.00: -10.50/5 1.fxe7 Nxe7 2.Bd2 Nf5 3.Qe2
0.00: -10.59/6 1.fxe7 Nxe7 2.Bd2 Qa4 3.Qxa4 Bxa4
0.00: -10.68/7 1.fxe7 Nxe7 2.Rh1 Nf5 3.Qe2 Bb5 4.Bf4 Bxd3
0.00: -10.20/8 1.Rh1 g6 2.fxe7 Nxe7 3.Qe2 Bb5 4.Bf4 Bxd3 5.Qxd3
0.00: -10.37/9 1.Rh1 g6 2.fxe7 Nxe7 3.Qe2 Bb5 4.Bf4 Bxd3 5.Qxd3 Qb5 6.Qe3
0.00: -10.39/10 1.Rh1 g6 2.fxe7 Nxe7 3.Ba3 Qe6 4.Nfd2 Rbe8 5.Bd6 Qb2 6.Qe2 Qg4+ 7.Qxg4 Bxg4
0.00: -10.48/11 1.Rh1 g6 2.fxe7 Nxe7 3.Ba3 Qe6 4.Nfd2 Rfe8 5.Bc2 Rbd8 6.Qf3 Qg4+ 7.Qxg4 Bxg4 8.Bd6 Nf5
0.00: -10.36/12 1.Rh1 g6 2.fxe7 Nxe7 3.Ba3 Qe6 4.Nfd2 Rfe8 5.Bc2 Rbd8 6.Qf3 Qg4+ 7.Qxg4 Bxg4 8.Ba4 Bd7 9.Bb3
0.00: -10.27/13 1.Nfd2 g6 2.fxe7 Nxe7 3.Rf6 Qb7 4.Qe2 Bf5 5.Ba3 Bxd3 6.Qxd3 Qa2 7.Bxe7 Qxe7
0.00: -10.43/14 1.Nfd2 g6 2.fxe7 Nxe7 3.Qf3 Bf5 4.Ba3 Qe6 5.Kh2 Bxd3 6.Qxd3 Rfe8 7.c4 Nf5 8.Bc5 dxc4
0.01: -10.54/15 1.Nfd2 g6 2.fxe7 Nxe7 3.Rf6 Qb7 4.Ba3 Bf5 5.Qf3 Bxd3 6.Qxd3 Qd7 7.Kh2 Rb7 8.Bd6 Qg4 9.Qg3 Qxg3+ 10.Kxg3 Qb2 11.Kg2
0.02: -10.65/16 1.Nfd2 g6 2.fxe7 Nxe7 3.Qf3 Bf5 4.Ba3 Bxd3 5.Qxd3 Qe6 6.Kh2 Rfe8 7.Qg3 Nf5 8.Qf3 Kg7 9.Kg1 a4 10.Bc5
0.04: -9.84/17 1.Rh1 h6 2.fxe7 Nxe7 3.gxh6 Nf5 4.hxg7 Qg6+ 5.Kf1 Rfc8 6.Bg5 Qxg7 7.Rg1 Ba4 8.Qe1 Bb5 9.Bxb5 Rxb5
0.06: -9.62/18 1.Rh1
0.12: -8.84/18 1.Qe1 g6 2.Qh4 Rfe8 3.fxe7 Nxe7 4.Rh1 h5 5.gxh6 Nf5 6.h7+ Kh8 7.Bxf5 Qa2+ 8.Kg3 Bxf5 9.Bg5 Re6 10.Nbd2 Qc2 11.Bf6+ Rxf6 12.Qxf6+ Qxf6 13.exf6
0.14: -9.07/19 1.Qe1 g6 2.Qh4 Rfc8 3.fxe7 Nxe7 4.Rh1 h5 5.gxh6 Qa2+ 6.Kg3 Nf5+ 7.Bxf5 gxf5 8.Bg5 Qg6 9.h7+ Kh8 10.Kf4 Rc6 11.Nbd2 Qc2 12.Bf6+ Rxf6 13.Qxf6+ Qxf6 14.exf6 Qxc3 15.Kg3 Rb2
0.24: -8.49/20 1.Qe1
0.27: -7.86/20 1.Bxh7+ Kxh7 2.Rh1+ Kg8 3.Nfd2 g6 4.Rh7 Bh3+ 5.Rxh3 Nxe5 6.fxe7 Rfe8 7.Qh1 f5 8.dxe5 Kf7 9.Rh7+ Ke6 10.Qh3 d4 11.Rg7 Kd7 12.Qd3 Qa2 13.Na3 Qc6+ 14.Kg1 Qxc3 15.e6+ Qxe6 16.Qxc3 dxc3
0.33: -5.26/21 1.Bxh7+ Kxh7 2.Rh1+ Kg8 3.Nfd2 Qxd4 4.cxd4 Qxd4 5.Qh5 Qg4+ 6.Qxg4 Bxg4 7.fxe7 Nxe7 8.Ba3 Rfe8 9.Kg3 Bf5 10.Nc3 d4 11.Ne2 Nc6 12.Rh4 d3 13.Nd4 Nxd4 14.Rxd4 Rxe5
0.34: -5.53/22 1.Bxh7+ Kxh7 2.Rh1+ Kg8 3.Nfd2 Qxd4 4.cxd4 Qxd4 5.Qh5 Qg4+ 6.Qxg4 Bxg4 7.fxe7 Nxe7 8.Ba3 Rfe8 9.Kg3 Bf5 10.Nc3 Rbc8 11.Rc1 Ng6 12.Bb2 Rb8 13.Ba3 d4 14.Ne2 d3 15.Nf4 Nxe5 16.Rc5 a4 17.Rd5 Kh7
0.40: -5.94/23 1.Bxh7+ Kxh7 2.Rh1+ Kg8 3.Nfd2 Qxd4 4.cxd4 Qxd4 5.Qh5 Qg4+ 6.Qxg4 Bxg4 7.fxe7 Nxe7 8.Ba3 Rfe8 9.Kg3 Bd7 10.Nc3 Rbc8 11.Rc1 Nf5+ 12.Kf4 Nd4 13.Bb2 Rb8 14.Rb1 Bc6 15.Na2 Ne6+ 16.Kg4 Bd7 17.Ba1 Rxb1 18.Nxb1 d4 19.Nc1 Rc8
0.47: -6.27/24 1.Bxh7+ Kxh7 2.Rh1+ Kg8 3.Nfd2 Qxd4 4.cxd4 Qxd4 5.Qh5 Qg4+ 6.Qxg4 Bxg4 7.fxe7 Nxe7 8.Ba3 Rfe8 9.Kg3 Bd7 10.Rd1 Nf5+ 11.Kf4 Rec8 12.Rc1 Rxc1 13.Bxc1 Rb4+ 14.Kf3 Rh4 15.Kf2 Rh2+ 16.Kg1 Rh3 17.Kf2 Bc6 18.Nf3 d4 19.Nbd2 Kh7 20.Bb2 Bxf3 21.Nxf3 Kg6 22.Bxd4 Rxf3+ 23.Kxf3 Nxd4+ 24.Ke4 Kxg5
1.29: 0.00/25 1.Bxh7+ Kxh7 2.Rh1+ Kg8 3.Rh8+ Kxh8 4.Qh1+ Kg8 5.fxg7 Kxg7 6.Qh6+ Kg8 7.g6 Bh3+ 8.Kxh3 fxg6 9.Qxg6+ Kh8 10.Qh6+ Kg8
4.44: +5.82/26 1.Bxh7+ Kxh7 2.Rh1+ Kg8 3.Rh8+ Kxh8 4.Qh1+ Kg8 5.g6 fxg6 6.Ng5 Qbb2+ 7.Bxb2 Qxb2+ 8.Kg3 Qf2+ 9.Kxf2 Rxf6+ 10.exf6 Bxf6 11.Qxd5+ Kh8 12.Nf7+ Kh7 13.Qxd7 Nd8 14.Nxd8 Bh4+ 15.Ke2 Rxd8 16.Qh3 g5 17.Kd3 Rf8 18.Nd2 Rf4 19.Nc4 a4 20.d5
6.05: +6.27/27 1.Bxh7+ Kxh7 2.Rh1+ Kg8 3.Rh8+ Kxh8 4.Qh1+ Kg8 5.g6 fxg6 6.Ng5 Qbb2+ 7.Bxb2 Qxb2+ 8.Kg3 Qf2+ 9.Kxf2 Rxf6+ 10.exf6 Bxf6 11.Qxd5+ Kh8 12.Nf7+ Kh7 13.Qxd7 Rf8 14.Qxc6 Rxf7 15.Qh1+ Kg8 16.Ke3 a4 17.Qa8+ Kh7 18.Nd2 Bg5+ 19.Kd3 Bxd2 20.Kxd2 a3 21.Qxa3 g5 22.Qa8 Kg6 23.Qe4+ Kf6 24.Qe5+ Kg6 25.Qe6+ Rf6
6.30: +6.14/28 1.Bxh7+
with tbs: Crystal 1.1 finds Bxh7+ within the same time, but switches (after a long think) to Rh1.
0.00: -10.43/3 1.fxe7 Nxe7 2.Bd2
0.00: -10.57/4 1.fxe7 Nxe7 2.Bd2 Nf5
0.00: -10.50/5 1.fxe7 Nxe7 2.Bd2 Nf5 3.Qe2
0.00: -10.59/6 1.fxe7 Nxe7 2.Bd2 Qa4 3.Qxa4 Bxa4
0.00: -10.68/7 1.fxe7 Nxe7 2.Rh1 Nf5 3.Qe2 Bb5 4.Bf4 Bxd3
0.00: -10.20/8 1.Rh1 g6 2.fxe7 Nxe7 3.Qe2 Bb5 4.Bf4 Bxd3 5.Qxd3
0.00: -10.37/9 1.Rh1 g6 2.fxe7 Nxe7 3.Qe2 Bb5 4.Bf4 Bxd3 5.Qxd3 Qb5 6.Qe3
0.00: -10.39/10 1.Rh1 g6 2.fxe7 Nxe7 3.Ba3 Qe6 4.Nfd2 Rbe8 5.Bd6 Qb2 6.Qe2 Qg4+ 7.Qxg4 Bxg4
0.00: -10.48/11 1.Rh1 g6 2.fxe7 Nxe7 3.Ba3 Qe6 4.Nfd2 Rfe8 5.Bc2 Rbd8 6.Qf3 Qg4+ 7.Qxg4 Bxg4 8.Bd6 Nf5
0.00: -10.36/12 1.Rh1 g6 2.fxe7 Nxe7 3.Ba3 Qe6 4.Nfd2 Rfe8 5.Bc2 Rbd8 6.Qf3 Qg4+ 7.Qxg4 Bxg4 8.Ba4 Bd7 9.Bb3
0.00: -10.27/13 1.Nfd2 g6 2.fxe7 Nxe7 3.Rf6 Qb7 4.Qe2 Bf5 5.Ba3 Bxd3 6.Qxd3 Qa2 7.Bxe7 Qxe7
0.00: -10.43/14 1.Nfd2 g6 2.fxe7 Nxe7 3.Qf3 Bf5 4.Ba3 Qe6 5.Kh2 Bxd3 6.Qxd3 Rfe8 7.c4 Nf5 8.Bc5 dxc4
0.01: -10.54/15 1.Nfd2 g6 2.fxe7 Nxe7 3.Rf6 Qb7 4.Ba3 Bf5 5.Qf3 Bxd3 6.Qxd3 Qd7 7.Kh2 Rb7 8.Bd6 Qg4 9.Qg3 Qxg3+ 10.Kxg3 Qb2 11.Kg2
0.02: -10.65/16 1.Nfd2 g6 2.fxe7 Nxe7 3.Qf3 Bf5 4.Ba3 Bxd3 5.Qxd3 Qe6 6.Kh2 Rfe8 7.Qg3 Nf5 8.Qf3 Kg7 9.Kg1 a4 10.Bc5
0.04: -9.84/17 1.Rh1 h6 2.fxe7 Nxe7 3.gxh6 Nf5 4.hxg7 Qg6+ 5.Kf1 Rfc8 6.Bg5 Qxg7 7.Rg1 Ba4 8.Qe1 Bb5 9.Bxb5 Rxb5
0.06: -9.62/18 1.Rh1
0.12: -8.84/18 1.Qe1 g6 2.Qh4 Rfe8 3.fxe7 Nxe7 4.Rh1 h5 5.gxh6 Nf5 6.h7+ Kh8 7.Bxf5 Qa2+ 8.Kg3 Bxf5 9.Bg5 Re6 10.Nbd2 Qc2 11.Bf6+ Rxf6 12.Qxf6+ Qxf6 13.exf6
0.14: -9.07/19 1.Qe1 g6 2.Qh4 Rfc8 3.fxe7 Nxe7 4.Rh1 h5 5.gxh6 Qa2+ 6.Kg3 Nf5+ 7.Bxf5 gxf5 8.Bg5 Qg6 9.h7+ Kh8 10.Kf4 Rc6 11.Nbd2 Qc2 12.Bf6+ Rxf6 13.Qxf6+ Qxf6 14.exf6 Qxc3 15.Kg3 Rb2
0.24: -8.49/20 1.Qe1
0.28: -7.86/20 1.Bxh7+ Kxh7 2.Rh1+ Kg8 3.Nfd2 g6 4.Rh7 Bh3+ 5.Rxh3 Nxe5 6.fxe7 Rfe8 7.Qh1 f5 8.dxe5 Kf7 9.Rh7+ Ke6 10.Qh3 d4 11.Rg7 Kd7 12.Qd3 Qa2 13.Na3 Qc6+ 14.Kg1 Qxc3 15.e6+ Qxe6 16.Qxc3 dxc3
0.33: -5.26/21 1.Bxh7+ Kxh7 2.Rh1+ Kg8 3.Nfd2 Qxd4 4.cxd4 Qxd4 5.Qh5 Qg4+ 6.Qxg4 Bxg4 7.fxe7 Nxe7 8.Ba3 Rfe8 9.Kg3 Bf5 10.Nc3 d4 11.Ne2 Nc6 12.Rh4 d3 13.Nd4 Nxd4 14.Rxd4 Rxe5
0.35: -5.53/22 1.Bxh7+ Kxh7 2.Rh1+ Kg8 3.Nfd2 Qxd4 4.cxd4 Qxd4 5.Qh5 Qg4+ 6.Qxg4 Bxg4 7.fxe7 Nxe7 8.Ba3 Rfe8 9.Kg3 Bf5 10.Nc3 Rbc8 11.Rc1 Ng6 12.Bb2 Rb8 13.Ba3 d4 14.Ne2 d3 15.Nf4 Nxe5 16.Rc5 a4 17.Rd5 Kh7
0.41: -5.94/23 1.Bxh7+ Kxh7 2.Rh1+ Kg8 3.Nfd2 Qxd4 4.cxd4 Qxd4 5.Qh5 Qg4+ 6.Qxg4 Bxg4 7.fxe7 Nxe7 8.Ba3 Rfe8 9.Kg3 Bd7 10.Nc3 Rbc8 11.Rc1 Nf5+ 12.Kf4 Nd4 13.Bb2 Rb8 14.Rb1 Bc6 15.Na2 Ne6+ 16.Kg4 Bd7 17.Ba1 Rxb1 18.Nxb1 d4 19.Nc1 Rc8
0.48: -6.27/24 1.Bxh7+ Kxh7 2.Rh1+ Kg8 3.Nfd2 Qxd4 4.cxd4 Qxd4 5.Qh5 Qg4+ 6.Qxg4 Bxg4 7.fxe7 Nxe7 8.Ba3 Rfe8 9.Kg3 Bd7 10.Rd1 Nf5+ 11.Kf4 Rec8 12.Rc1 Rxc1 13.Bxc1 Rb4+ 14.Kf3 Rh4 15.Kf2 Rh2+ 16.Kg1 Rh3 17.Kf2 Bc6 18.Nf3 d4 19.Nbd2 Kh7 20.Bb2 Bxf3 21.Nxf3 Kg6 22.Bxd4 Rxf3+ 23.Kxf3 Nxd4+ 24.Ke4 Kxg5
1.03: -5.99/25 1.Bxh7+ Kxh7 2.Rh1+ Kg8 3.Nfd2 Qxd4 4.cxd4 Qxd4 5.Qh5 Qg4+ 6.Qxg4 Bxg4 7.fxe7 Nxe7 8.Ba3 Rfe8 9.Kg3 Bf5 10.Nc3 Rbc8 11.Rc1 Ng6 12.Nf3 Be4 13.e6 Rxe6 14.Nxe4 Rxc1 15.Bxc1 dxe4 16.Nd4 Rd6 17.Be3 a4 18.Nc2 Rd3 19.Kf2
1.03: -6.09/26 1.Bxh7+ Kxh7
12.44: -1.90/26 1.Rh1
Does it occur on other systems too
Also possible that my mac compile is broken.
Hope we're not just the biological boot loader for digital super intelligence. Unfortunately, that is increasingly probable - Elon Musk