[d]3B3k/5pp1/5R2/p4pK1/P7/8/p7/8 w - -
It has been around a long time and a reference to it can be found in a thread by Dan Corbit on the Winboard forum
http://www.open-aurec.com/wbforum/viewt ... F8#p185631
It is published with the solution of Rh6+, but not so fast.
Code: Select all
FEN: 3B3k/5pp1/5R2/p4pK1/P7/8/p7/8 w - - 0 1
Houdini 6:
Nalimov 6 men EGTB available - 32 MB cache
15 00:00 2,768k 8,362k -3.57 1.Rh6+ gxh6+ 2.Kxf5 a1Q 3.Bf6+ Qxf6+ 4.Kxf6 Kh7 5.Ke5 Kg6 6.Kf4 h5 7.Kg3 Kg5 8.Kg2 h4 9.Kg1 f5 10.Kg2
15 00:00 5,760k 9,143k -3.13 1.Rxf7 a1Q 2.Kg6 Kg8 3.Bg5 Qc3 4.Re7 Qc6+ 5.Kxf5 Qxa4 6.Re3 Qc2+ 7.Kg4 a4 8.Be7 Kf7 9.Kf3 Qc7 10.Ba3 g5 11.Re7+ Qxe7 12.Bxe7
16 00:00 8,806k 9,388k -3.19 1.Rxf7 a1Q 2.Kg6 Kg8 3.Bg5 Qc3 4.Re7 Qc6+ 5.Kxf5 Qxa4 6.Be3 Qb5+ 7.Kf4 Qb4+ 8.Re4 Qd6+ 9.Kf3 Qd1+ 10.Kf4 a4 11.Bc5 Qc1+ 12.Be3 Qf1+ 13.Ke5 a3
17 00:01 9,844k 9,393k -3.27 1.Rxf7 a1Q 2.Kg6 Kg8 3.Bg5 Qc3 4.Re7 Qc6+ 5.Kxf5 Qc2+ 6.Kg4 Qxa4+ 7.Bf4 Qd4 8.Re3 a4 9.Kf3 Qd5+ 10.Ke2 Qb5+ 11.Kf3 Qc5 12.Ke2 a3 13.Be5
18 00:01 12,009k 9,345k -3.41 1.Rxf7 a1Q 2.Kg6 Kg8 3.Bg5 Qc3 4.Re7 Qc6+ 5.Kxf5 Qc2+ 6.Kg4 Qxa4+ 7.Bf4 Qd4 8.Re3 a4 9.Kf3 Qc5 10.Be5 a3 11.Ke2 Qc2+ 12.Ke1 a2 13.Bd4 Qc1+ 14.Ke2
19 00:01 15,312k 9,492k -3.38 1.Rxf7 a1Q 2.Kg6 Kg8 3.Bg5 Qc3 4.Re7 Qc6+ 5.Kxf5 Qc2+ 6.Kg4 Qxa4+ 7.Bf4 Qd4 8.Re3 a4 9.Kf3 Qc5 10.Be5 a3 11.Bc3 Qc4 12.Kf2 a2 13.Re8+ Kf7 14.Re3 Qxc3 15.Rxc3 a1Q 16.Rf3+
20 00:02 28,112k 10,029k -3.76 1.Rxf7 a1Q 2.Kg6 Kg8 3.Bg5 Qc3 4.Re7 Qc6+ 5.Kxf5 Qc2+ 6.Kg4 Qxa4+ 7.Bf4 Qd1+ 8.Kf5 Qc2+ 9.Kg4 a4 10.Re3 Qc5 11.Kf3 a3 12.Be5 a2 13.Kf2 Qc2+ 14.Ke1 g5 15.Re2 Qc1+ 16.Kf2 Qb1 17.Ke3
21 00:03 35,152k 10,537k -3.84 1.Rxf7 a1Q 2.Kg6 Kg8 3.Bg5 Qc3 4.Re7 Qc6+ 5.Kxf5 Qc2+ 6.Kg4 Qxa4+ 7.Bf4 Qd1+ 8.Kf5 Qc2+ 9.Kg4 a4 10.Re3 Qc5 11.Kf3 a3 12.Be5 a2 13.Re4 Kf7 14.Bd4 Qc6 15.Ke3 g5 16.Re5
22 00:05 58,008k 11,580k -4.04 1.Rxf7 a1Q 2.Kg6 Kg8 3.Bg5 Qc3 4.Re7 Qc6+ 5.Kxf5 Qc2+ 6.Kg4 Qxa4+ 7.Bf4 Qd1+ 8.Kf5 Qc2+ 9.Kg4 a4 10.Re3 Qc5 11.Kf3 a3 12.Be5 a2 13.Ke4 Qc4+ 14.Kf3 g5 15.Re4 Qc6 16.Bd4
23 00:13 184,834k 13,905k -6.05 1.Kxf5 a1Q 2.Rd6 g6+ 3.Ke4 Qxa4+ 4.Ke5 Kg7 5.Bf6+ Kh7 6.Rb6 Qc4 7.Kd6 a4 8.Rc6 Qd3+ 9.Ke7 Qe4+ 10.Kd6 a3 11.Kc5 Qf5+ 12.Kc4 a2 13.Kb4 Qb1+ 14.Kc5 a1Q 15.Bxa1 Qxa1 16.Kb5 Qb2+ 17.Ka4 g5 18.Rc4
24 00:16 229,079k 13,891k -6.76 1.Kxf5 a1Q 2.Rd6 g6+ 3.Ke4 Qxa4+ 4.Ke5 Kg7 5.Bf6+ Kh7 6.Rb6 Qc4 7.Kd6 a4 8.Rc6 Qd3+ 9.Ke7 Qe4+ 10.Kd6 a3 11.Kc5 a2 12.Bc3 g5 13.Rc7 Qe3+ 14.Kb5 Qd3+ 15.Rc4 g4 16.Kb4 Qxc3+ 17.Kxc3 a1Q+ 18.Kd2 Qa5+ 19.Kd3
25 00:20 290,988k 13,989k -7.18 1.Kxf5 a1Q 2.Rd6 g6+ 3.Ke4 Qxa4+ 4.Ke5 Kg7 5.Rd5 Qa1+ 6.Kd6 a4 7.Bb6 Qf6+ 8.Kc7 Qf4+ 9.Kd7 a3 10.Bd4+ Kh7 11.Ba1 Qg4+ 12.Kc6 a2 13.Rc5 g5 14.Bc3 Qe4+ 15.Kb5 g4 16.Rc4 Qd3 17.Kb4 Qxc3+ 18.Kxc3
26 00:26 373,445k 14,176k -7.69 1.Kxf5 a1Q 2.Rd6 g6+ 3.Ke4 Qxa4+ 4.Ke5 Kg7 5.Rd5 Qa1+ 6.Kd6 a4 7.Bb6 Qf6+ 8.Kc7 Qf4+ 9.Kd7 a3 10.Bd4+ Kh7 11.Ba1 Qg4+ 12.Kc6 Qe4 13.Kc5 a2 14.Kc6 g5 15.Kd6 Qb1 16.Bd4 Qb4+ 17.Kc7 Qxd4 18.Rxd4 a1Q 19.Re4 Qa5+ 20.Kd6
27 00:47 678,965k 14,328k -10.78 1.Kxf5 a1Q 2.Rd6 g6+ 3.Ke4 Qxa4+ 4.Ke3 Qa3+ 5.Rd3 Qc5+ 6.Ke2 Kg7 7.Re3 Qc4+ 8.Kf2 a4 9.Be7 f5 10.Ba3 g5 11.Bb2+ Kf7 12.Re2 f4 13.Rd2 g4 14.Bd4 Qc1 15.Ke2 g3 16.Kd3 f3 17.Be3 Qb1+ 18.Kd4 f2 19.Bxf2 Qb6+ 20.Kd3
28 01:32 1,347,255k 14,622k -75.20 1.Kxf5 a1Q 2.Rd6 g6+ 3.Ke4 Qxa4+ 4.Ke5 Kg7 5.Bf6+ Kh7 6.Bd8 Qb5+ 7.Kf6 Qc5 8.Ke7 a4 9.Bb6 Qb4 10.Bd4 a3 11.Kd7 a2 12.Bf6 Qa4+ 13.Rc6 a1Q 14.Bxa1 Qxa1 15.Ke7 Kg7 16.Ke8 Qa8+ 17.Kd7 Qxc6+ 18.Kxc6 g5 19.Kd5 g4 20.Ke4 g3 21.Ke3
29 01:35 1,401,327k 14,684k -75.20 1.Kxf5 a1Q 2.Rd6 g6+ 3.Ke4 Qxa4+ 4.Ke5 Kg7 5.Bf6+ Kh7 6.Rb6 Qc4 7.Kd6 a4 8.Rc6 Qd3+ 9.Ke7 Qe4+ 10.Kd6 a3 11.Bc3 a2 12.Kc5 Qf5+ 13.Kc4 Qc2 14.Kd5 a1Q 15.Bxa1 Qa2+ 16.Rc4 Qxa1 17.Rc7 Kg7 18.Kc6 Qa5 19.Rc8
30 01:35 1,408,529k 14,693k -75.20 1.Kxf5 a1Q 2.Rd6 g6+ 3.Ke4 Qxa4+ 4.Ke5 Kg7 5.Bf6+ Kh7 6.Rb6 Qc4 7.Kd6 a4 8.Rc6 Qd3+ 9.Ke7 Qe4+ 10.Kd6 a3 11.Bc3 a2 12.Kc5 Qf5+ 13.Kc4 Qc2 14.Kd5 a1Q 15.Bxa1 Qa2+ 16.Rc4 Qxa1 17.Rc7 Kg7 18.Kc6 Qa5 19.Rc8
31 01:37 1,433,849k 14,732k -75.20 1.Kxf5 a1Q 2.Rd6 g6+ 3.Ke4 Qxa4+ 4.Ke5 Kg7 5.Bf6+ Kh7 6.Rb6 Qc4 7.Kd6 a4 8.Rc6 Qd3+ 9.Ke7 Qe4+ 10.Kd6 a3 11.Bc3 a2 12.Kc5 Qf5+ 13.Kc4 Qc2 14.Kd5 a1Q 15.Bxa1 Qa2+ 16.Rc4 Qxa1 17.Rc7 Kg7 18.Kc6 Qa5 19.Rc8 Qc3+ 20.Kb7
32 01:39 1,472,003k 14,807k -75.20 1.Kxf5 a1Q 2.Rd6 g6+ 3.Ke4 Qxa4+ 4.Ke5 Kg7 5.Bf6+ Kh7 6.Rb6 Qc4 7.Kd6 a4 8.Rc6 Qd3+ 9.Ke7 Qe4+ 10.Kd6 a3 11.Bc3 a2 12.Kc5 Qf5+ 13.Kc4 Qc2 14.Kd5 a1Q 15.Bxa1 Qa2+ 16.Rc4 Qxa1 17.Rc7 Kg7 18.Rc4 Qa5+ 19.Ke4 Qe1+ 20.Kd3 Qd1+ 21.Kc3
33 01:40 1,496,731k 14,844k -75.20 1.Kxf5 a1Q 2.Rd6 g6+ 3.Ke4 Qxa4+ 4.Ke5 Kg7 5.Bf6+ Kh7 6.Rb6 Qc4 7.Kd6 a4 8.Rc6 Qd3+ 9.Ke7 Qe4+ 10.Kd6 a3 11.Bc3 a2 12.Kc5 Qf5+ 13.Kc4 Qc2 14.Kd5 a1Q 15.Bxa1 Qa2+ 16.Rc4 Qxa1 17.Rc7 Kg7 18.Rc4 Qa5+ 19.Ke4 Qe1+ 20.Kd3 Qd1+ 21.Kc3 Qc1+ 22.Kb4 Qd2+ 23.Kb3 Qd3+ 24.Kb4
34 01:47 1,606,324k 15,001k -75.20 1.Kxf5 a1Q 2.Rd6 g6+ 3.Ke4 Qxa4+ 4.Ke5 Qb5+ 5.Kf6 Qb4 6.Rd5 Qc4 7.Rd6 a4 8.Ke7 a3 9.Kf8 Qc5 10.Be7 a2 11.Bf6+ Kh7 12.Ke7 Qb4 13.Kd7 Qb7+ 14.Ke8 a1Q 15.Bxa1 Qa8+ 16.Kd7 Qxa1 17.Ke7 g5 18.Rd5 Qa3+ 19.Kd7 Qa7+ 20.Kc6 Qa6+ 21.Kc5 Qa5+ 22.Kd4 Qb4+ 23.Ke3
35 01:53 1,709,208k 15,100k -75.40 1.Kxf5 a1Q 2.Rd6 g6+ 3.Ke4 Qxa4+ 4.Ke5 Kg7 5.Bf6+ Kh7 6.Rb6 Qc4 7.Kd6 a4 8.Rc6 Qd3+ 9.Ke7 Qe4+ 10.Kd7 a3 11.Rd6 Qf5+ 12.Kc6 a2 13.Kb6 Qxf6 14.Rxf6 a1Q 15.Rd6 Qc3 16.Kb5 Qe5+ 17.Kc6 Qxd6+ 18.Kxd6 f5 19.Ke5 Kg7 20.Kf4 Kh6 21.Kg3 f4+ 22.Kh3
36 01:56 1,769,887k 15,158k -75.40 1.Kxf5 a1Q 2.Rd6 g6+ 3.Ke4 Qxa4+ 4.Ke5 Kg7 5.Rd5 Qa1+ 6.Kd6 a4 7.Bb6 Qf6+ 8.Kc7 Qf4+ 9.Kc6 Qc4+ 10.Kd6 a3 11.Ra5 a2 12.Ra7 Qe6+ 13.Kc5 Qe3+ 14.Kc6 Qf3+ 15.Kd6 Qf6+ 16.Kc7 Qe5+ 17.Kb7 a1Q 18.Rxa1 Qxa1 19.Bc5 Kh7 20.Kc6 Qa6+ 21.Kc7 Qa5+ 22.Kc6 Qc3 23.Kd6 Qf6+ 24.Kd5 Qf5+ 25.Kc6 Qc8+ 26.Kd6 Qe6+ 27.Kc7
37 02:09 1,984,795k 15,340k -75.80 1.Kxf5 a1Q 2.Rd6 g6+ 3.Ke4 Qxa4+ 4.Ke5 Kg7 5.Rd5 Qa1+ 6.Kd6 a4 7.Bb6 Qf6+ 8.Kc7 Qf4+ 9.Kc6 Qc4+ 10.Rc5 Qe4+ 11.Kc7 a3 12.Ba5 Qe7+ 13.Kc6 Qf6+ 14.Kd7 Qd4+ 15.Kc6 a2 16.Bc3 Qxc3 17.Rxc3 a1Q 18.Rc5 Qa6+ 19.Kd5 Qe6+ 20.Kd4 Qg4+ 21.Kc3 Qg3+ 22.Kc4 Qf4+ 23.Kb3 Qe3+ 24.Rc3 Qxc3+ 25.Kxc3 Kh6 26.Kb2 f5 27.Kc3 f4 28.Kc4
38 05:11 5,652,924k 18,175k -M43 1.Kxf5 a1Q 2.Rd6 g6+ 3.Ke4 Qxa4+ 4.Ke5 Kg7 5.Bf6+ Kh7 6.Rb6 Qc4 7.Kd6 a4 8.Rc6 Qd3+ 9.Kc7 a3 10.Rc1 Qe4 11.Kd8 Qf3 12.Ba1 a2 13.Re1 Qd3+ 14.Ke8 Qb1 15.Bc3 Qxe1+ 16.Bxe1 a1Q 17.Bg3 Qa4+ 18.Ke7 Qa7+ 19.Kf6 Qd7 20.Bb8 Qe8 21.Bh2 Qe6+ 22.Kg5 Qe3+ 23.Bf4 Qf3 24.Bc1 f6+ 25.Kh4
39 05:48 6,432,299k 18,482k -M43 1.Kxf5 a1Q 2.Rd6 g6+ 3.Ke4 Qxa4+ 4.Ke5 Kg7 5.Bf6+ Kh7 6.Rb6 Qc4 7.Kd6 a4 8.Rc6 Qd3+ 9.Kc7 a3 10.Rc1 Qe4 11.Kd8 Qf3 12.Ba1 a2 13.Re1 Qd3+ 14.Ke8 Qb1 15.Bc3 Qxe1+ 16.Bxe1 a1Q 17.Bg3 Qa4+ 18.Ke7 Qa7+ 19.Kf6 Qa3 20.Be5 Qf3+ 21.Ke7 Qb7+ 22.Kf6 Qc6+ 23.Kg5 Qe4 24.Bh2 Qg2+ 25.Kf4 Qxh2+ 26.Kf3
40 06:02 6,727,190k 18,581k -M43 1.Kxf5 a1Q 2.Rd6 g6+ 3.Ke4 Qxa4+ 4.Ke3 Qa3+ 5.Rd3 Qc5+ 6.Ke2 Kg7 7.Re3 Qc4+ 8.Kf2 a4 9.Ba5 Qf4+ 10.Ke2 Qxe3+ 11.Kxe3
41 06:09 6,894,043k 18,674k -M43 1.Kxf5 a1Q 2.Rd6 g6+ 3.Ke4 Qxa4+ 4.Ke3 Qa3+ 5.Rd3 Qc5+ 6.Ke2 Kg7 7.Re3 Qc4+ 8.Kf2 a4 9.Ba5 Qf4+ 10.Ke2 Qxe3+ 11.Kxe3
42 07:09 8,216,067k 19,139k -M43 1.Kxf5 a1Q 2.Rd6 g6+ 3.Ke4 Qxa4+ 4.Ke3 Qa3+ 5.Rd3 Qc5+ 6.Ke2 Kg7 7.Re3 Qc4+ 8.Kf2 a4 9.Ba5 Qf4+ 10.Ke2 Qxe3+ 11.Kxe3
43 07:38 8,833,855k 19,280k -M43 1.Kxf5 a1Q 2.Rd6 g6+ 3.Ke4 Qxa4+ 4.Ke3 Qa3+ 5.Rd3 Qc5+ 6.Ke2 Kg7 7.Re3 Qc4+ 8.Kf2 a4 9.Ba5 Qf4+ 10.Ke2 Qxe3+ 11.Kxe3
44 09:15 10,889,611k 19,607k -M43 1.Kxf5 a1Q 2.Rd6 g6+ 3.Ke4 Qxa4+ 4.Ke3 Qa3+ 5.Rd3 Qc5+ 6.Ke2 Kg7 7.Re3 Qc4+ 8.Kf2 a4 9.Ba5 Qf4+ 10.Ke2 Qxe3+ 11.Kxe3
45 11:16 13,304,954k 19,668k -M43 1.Kxf5 a1Q 2.Rd6 g6+ 3.Ke4 Qxa4+ 4.Ke3 Qa3+ 5.Rd3 Qc5+ 6.Ke2 Kg7 7.Re3 Qc4+ 8.Kf2 a4 9.Ba5 Qf4+ 10.Ke2 Qxe3+ 11.Kxe3
46 14:50 18,053,520k 20,268k -M41 1.Kxf5 a1Q 2.Rd6 g6+ 3.Ke4 Qxa4+ 4.Ke3 Qa3+ 5.Rd3 Qc5+ 6.Ke2 Kg7 7.Re3 Qc4+ 8.Kf2 a4 9.Be7 f5 10.Ba3 g5 11.Bb2+ Kf7 12.Re2 Qxe2+ 13.Kxe2
47 30:23 40,043,035k 21,957k -M28 1.Kxf5 a1Q 2.Rd6 f6 3.Ke6 Qxa4 4.Ke7 Qe4+ 5.Kf7 a4 6.Bb6 a3 7.Bd4 a2 8.Rd7 Kh7 9.Ba1 Qc4+ 10.Kf8 Qc8+ 11.Ke7 Qc1 12.Bd4 a1Q 13.Bxa1 Qxa1
47 34:14 46,215,108k 22,489k -M30 1.Rxf7 a1Q 2.Bc7 Kh7 3.Rxf5 Qg1+ 4.Kh4 Qh1+ 5.Kg4 Qe4+ 6.Rf4 Qb7 7.Bd6 Qd7+ 8.Kg5 Qxd6 9.Rh4+ Kg8 10.Re4 Kf7 11.Rf4+ Ke6 12.Re4+ Kd5 13.Rf4 Qxf4+
48 34:30 46,494,081k 22,457k -M29 1.Rxf7 a1Q 2.Bc7 Kh7 3.Rxf5 Qg1+ 4.Kh4 Qd4+ 5.Rf4 Qd7 6.Be5 Qd5 7.Rf5 Qe4+ 8.Kg5 Qg2+ 9.Kh4 Kg6 10.Rf4 Qg5+ 11.Kh3 Qxe5 12.Kg4 Qe3 13.Rf3 Qe4+ 14.Kg3 Qxa4
49 36:59 49,122,780k 22,131k -M29 1.Rxf7 a1Q 2.Bc7 Kh7 3.Rxf5 Qg1+ 4.Kh4 Qd4+ 5.Rf4 Qd7 6.Be5 Qd5 7.Rf5 Qe4+ 8.Kg5 Qg2+ 9.Kh4 Kg6 10.Rf4 Qg5+ 11.Kh3 Qxe5 12.Kg4 Qe3 13.Rf3 Qe4+ 14.Kg3 Qxa4
50 38:55 51,562,353k 22,074k -M28 1.Rxf7 a1Q 2.Bc7 Kh7 3.Rxf5 Qe1 4.Bb8 Qe7+ 5.Kg4 Qd7 6.Kf4 Qxa4+ 7.Kg5 Qb4 8.Bg3 a4 9.Rf4 Qe7+ 10.Kf5 a3 11.Rf2 Qc5+ 12.Kf4 a2 13.Rxa2
51 40:48 53,553,986k 21,873k -M28 1.Rxf7 a1Q 2.Bc7 Kh7 3.Rxf5 Qe1 4.Bb8 Qe7+ 5.Kg4 Qd7 6.Kf4 Qxa4+ 7.Kg5 Qb4 8.Bg3 a4 9.Rf4 Qe7+ 10.Kf5 a3 11.Rf2 Qc5+ 12.Kf4 a2 13.Rxa2
52 42:02 55,234,143k 21,899k -M28 1.Rxf7 a1Q 2.Bc7 Kh7 3.Rxf5 Qe1 4.Bb8 Qe7+ 5.Kg4 Qd7 6.Kf4 Qxa4+ 7.Kg5 Qb4 8.Bg3 a4 9.Rf4 Qe7+ 10.Kf5 a3 11.Rf2 Qc5+ 12.Kf4 a2 13.Rxa2
53 44:22 57,912,099k 21,754k -M28 1.Rxf7 a1Q 2.Bc7 Kh7 3.Rxf5 Qe1 4.Bb8 Qe7+ 5.Kg4 Qd7 6.Kf4 Qxa4+ 7.Kg5 Qb4 8.Bg3 a4 9.Rf4 Qe7+ 10.Kf5 a3 11.Rf2 Qc5+ 12.Kf4 a2 13.Rxa2
54 45:21 58,988,361k 21,676k -M28 1.Rxf7 a1Q 2.Bc7 Kh7 3.Rxf5 Qe1 4.Bb8 Qe7+ 5.Kg4 Qd7 6.Kf4 Qxa4+ 7.Kg5 Qb4 8.Bg3 a4 9.Rf4 Qe7+ 10.Kf5 a3 11.Rf2 Qc5+ 12.Kf4 a2 13.Rxa2
55 47:25 61,220,987k 21,511k -M28 1.Rxf7 a1Q 2.Bc7 Kh7 3.Rxf5 Qe1 4.Bb8 Qe7+ 5.Kg4 Qd7 6.Kf4 Qxa4+ 7.Kg5 Qb4 8.Bg3 a4 9.Rf4 Qe7+ 10.Kf5 a3 11.Rf2 Qc5+ 12.Kf4 a2 13.Rxa2
56 51:42 65,745,459k 21,192k -M28 1.Rxf7 a1Q 2.Bc7 Kh7 3.Rxf5 Qe1 4.Bh2 Qd2+ 5.Rf4 Qxh2 6.Rh4+ Qxh4+
57 56:48 71,045,854k 20,841k -M28 1.Rxf7 a1Q 2.Bc7 Kh7 3.Rxf5 Qe1 4.Bh2 Qd2+ 5.Rf4 Qxh2 6.Rh4+ Qxh4+
58 57:43 71,993,836k 20,785k -M28 1.Rxf7 a1Q 2.Bc7 Kh7 3.Rxf5 Qe1 4.Bh2 Qd2+ 5.Rf4 Qxh2 6.Rh4+ Qxh4+
59 1:03:38 78,171,935k 20,474k -M28 1.Rxf7 a1Q 2.Bc7 Kh7 3.Rxf5 Qe1 4.Bh2 Qd2+ 5.Rf4 Qxh2 6.Rh4+ Qxh4+
60 1:17:52 93,393,474k 19,989k -M28 1.Rxf7 a1Q 2.Kg6 Qg1+ 3.Bg5 Qb6+ 4.Bf6 Qxf6+ 5.Rxf6 gxf6
61 1:18:27 94,005,303k 19,970k -M28 1.Rxf7 a1Q 2.Kg6 Qg1+ 3.Bg5 Qb6+ 4.Bf6 Qxf6+ 5.Rxf6 gxf6
62 1:19:05 94,674,168k 19,950k -M28 1.Rxf7 a1Q 2.Kg6 Qg1+ 3.Bg5 Qb6+ 4.Bf6 Qxf6+ 5.Rxf6 gxf6
63 1:20:05 96,123,326k 20,003k -M28 1.Rxf7 a1Q 2.Kg6 Qg1+ 3.Bg5 Qb6+ 4.Bf6 Qxf6+ 5.Rxf6 gxf6
64 1:21:10 97,400,554k 19,998k -M28 1.Rxf7 a1Q 2.Kg6 Qg1+ 3.Bg5 Qb6+ 4.Bf6 Qxf6+ 5.Rxf6 gxf6
65 1:23:04 99,555,527k 19,972k -M28 1.Rxf7 a1Q 2.Kg6 Qg1+ 3.Bg5 Qb6+ 4.Bf6 Qxf6+ 5.Rxf6 gxf6
SF11 with syzygy doesn't switch over to Rxf7 till 47ply.
Please try the position on some good hardware and let us know what you find.