Rook sac with a quadruple winning pawn

[beram]

Really nice win from a SF8 vs K103 match by Hurnavich at 40/4 LTC
(http://rybkaforum.net/cgi-bin/rybkaforu ... ?tid=31923)
Game 2 shows the black win by SF8 with a quadruple pawn and a rook sac

[D] 6k1/5p2/2bp1p1b/4q2p/1QP1PpP1/rP3B1P/4K3/2N1R3 b - - 0 48
d5! with a surprisingly winning rook sac, SF8 spots this really fast Houdini takes longer
and Komodo takes >5 minutes

and the quadruple winning pawns position
[D] 6k1/Q4p2/2bq1p1b/7P/2P2p2/1P3p1P/8/2N1RK2 b - - 0 52


[pgn]
[Event "StockFish 8 vs Komodo 10.3, Rapid 40m+4"]
[Site "Hurnavich-PC"]
[Date "2016.12.31"]
[Round "2"]
[White "Komodo 10.3 64-bit LTC"]
[Black "StockFish 8 MP"]
[Result "0-1"]
[ECO "B96"]
[Annotator "0.05;0.20"]
[PlyCount "112"]
[EventDate "2016.??.??"]
[TimeControl "2400+4"]

{AMD Phenom(tm) II X6 1100T Processor 3625 MHz W=30.8 plies; 8,410kN/s; 6,495,
173 TBAs B=30.7 plies; 8,306kN/s; 3,707,636 TBAs} 1. e4 c5 2. Nf3 d6 3. d4 cxd4
4. Nxd4 Nf6 5. Nc3 a6 6. Bg5 Nbd7 7. f4 e6 8. Qe2 Be7 9. O-O-O Qc7 10. g4 b5
11. a3 {Both last book move} h6 {[%eval 20,29] 108} 12. Bh4 {[%eval 5,29] 82}
Bb7 {[%eval 11,29] [%emt 0:00:43]} 13. Kb1 {[%eval 19,31] 114 (f5)} Rc8 {
[%eval 0,31] [%emt 0:00:27]} 14. Bg2 {[%eval 6,31] 116} Qc4 {[%eval 0,28]
[%emt 0:00:51]} 15. Qe1 {[%eval 0,31] 121 (h3)} b4 {[%eval -32,29] [%emt 0:00:
28]} 16. axb4 {[%eval -6,29] [%emt 0:00:28]} Qxb4 {[%eval -17,28] [%emt 0:00:
18]} 17. Nb3 {[%eval 0,32] 134 (Bxf6)} Nc5 {[%eval 0,30] 125} 18. Rd4 {[%eval
-6,30] [%emt 0:00:39]} Qb6 {[%eval -13,33] [%emt 0:00:59]} 19. Nxc5 {[%eval -6,
30] [%emt 0:00:31]} Qxc5 {[%eval -12,31] [%emt 0:00:26]} 20. Rd3 {[%eval 0,29]
[%emt 0:00:37]} a5 {[%eval -18,32] 85 (Rb8)} 21. Qd2 {[%eval 0,33] 60} Ba6 {
[%eval -2,35] 338} 22. Bxf6 {[%eval 0,36] 84} gxf6 {[%eval -27,30] [%emt 0:00:
38]} 23. Rd4 {[%eval 0,33] [%emt 0:00:47] (Na4)} Rb8 {[%eval -27,30] [%emt 0:
00:44]} 24. b3 {[%eval 0,34] [%emt 0:00:51] (Nd1)} Rb4 {[%eval -36,31] [%emt 0:
00:43] (Bc8)} 25. Rxb4 {[%eval 0,34] 60} axb4 {[%eval -16,34] 83} 26. Na2 {
[%eval 0,33] [%emt 0:00:22]} O-O {[%eval -37,31] [%emt 0:00:07] (Bb7)} 27. Nxb4
{[%eval -6,35] 142} Bb5 {[%eval -44,32] [%emt 0:00:41] (Ra8)} 28. Rd1 {[%eval
-27,32] 93} Ra8 {[%eval -46,31] [%emt 0:00:11]} 29. Qd4 {[%eval -14,32] [%emt
0:00:36]} Qc7 {[%eval -57,34] [%emt 0:00:54]} 30. Nd3 {[%eval -29,33] 75} e5 {
[%eval -41,33] [%emt 0:00:18]} 31. Qb2 {[%eval -34,31] [%emt 0:00:21]} Qa7 {
[%eval -40,34] 140} 32. Nc1 {[%eval -31,32] [%emt 0:00:44]} exf4 {[%eval -35,
33] [%emt 0:00:53]} 33. Qd4 {[%eval -30,32] 70} Qa5 {[%eval -44,33] [%emt 0:00:
11]} 34. c4 {[%eval -29,32] 82} Bc6 {[%eval -50,30] [%emt 0:00:28]} 35. Kc2 {
[%eval -36,29] [%emt 0:00:20] (Rf1)} Bf8 {[%eval -33,31] 128 (Qe5)} 36. Rd3 {
[%eval -25,30] 102} Re8 {[%eval -41,32] 64} 37. Rd2 {[%eval -28,28] [%emt 0:00:
17]} Qa8 {[%eval -47,29] [%emt 0:00:24]} 38. h3 {[%eval -35,31] 74 (Re2)} Re6 {
[%eval -42,29] [%emt 0:00:48] (Re5)} 39. Re2 {[%eval -21,30] [%emt 0:00:26]}
Bg7 {[%eval -58,30] [%emt 0:00:30]} 40. Qd3 {[%eval -33,29] [%emt 0:00:23]} h5
{[%eval -60,29] [%emt 0:00:07]} 41. Kd1 {[%eval -35,30] [%emt 0:00:29]} Re7 {
[%eval -36,32] 142 (hxg4)} 42. Rd2 {[%eval -36,32] [%emt 0:00:47]} Re8 {[%eval
-54,29] [%emt 0:00:33]} 43. Re2 {[%eval -46,34] 128 (Bf3)} Qa5 {[%eval -80,30]
[%emt 0:00:37] (hxg4)} 44. Qd2 {[%eval -44,32] [%emt 0:00:57]} Qe5 {[%eval -85,
29] [%emt 0:00:38]} 45. Bf3 {[%eval -37,30] [%emt 0:00:33]} Ra8 {[%eval -68,31]
62} 46. Re1 {[%eval -57,29] [%emt 0:00:16] (Ke1)} Ra3 {[%eval -94,29] [%emt 0:
00:16]} 47. Ke2 {[%eval -58,31] [%emt 0:00:33]} Bh6 {[%eval -92,30] [%emt 0:00:
21]} 48. Qb4 {[%eval -71,30] [%emt 0:00:31] (Kf1)} d5 {[%eval -157,27] [%emt 0:
00:32] (Qd4)} 49. Qxa3 {[%eval -201,30] [%emt 0:00:41] (cxd5)} dxe4 {[%eval
-298,30] [%emt 0:00:20]} 50. Qa7 {[%eval -304,30] [%emt 0:00:33]} exf3+ {
[%eval -354,30] [%emt 0:00:10] (Qc3)} 51. Kf1 {[%eval -311,31] [%emt 0:00:23]}
Qd6 {[%eval -510,31] [%emt 0:00:12] (Qc3)} 52. gxh5 {[%eval -284,30] [%emt 0:
00:13]} Bg5 {[%eval -553,30] [%emt 0:00:04]} 53. Qg1 {[%eval -500,33] [%emt 0:
00:21]} Qd2 {[%eval -661,32] [%emt 0:00:11]} 54. h4 {[%eval -698,34] [%emt 0:
00:34]} Bd7 {[%eval -843,33] [%emt 0:00:17]} 55. Qf2 {[%eval -693,34] [%emt 0:
00:22]} Qxf2+ {[%eval -811,28] [%emt 0:00:04]} 56. Kxf2 {[%eval -692,5] [%emt
0:00:00]} Bxh4+ {[%eval -1109,30] [%emt 0:00:16]} 0-1
[/pgn]

[yanquis1972]

komodo finds it within 30 seconds or so on my searches (using 10 of 12 logical threads bc larry said he does similar). houdini seems pretty variable. latest (?) SF build is consistently quite fast tho.

[yanquis1972]

seems my initial searches w/ K were quite lucky as i haven't been able to reproduce that result after 4-5 searches. houdini seems faster but can still take over a minute. SF consistently under 30 seconds. dont know how they do it but i sure hope someone can figure it out!

[beram]

seems my initial searches w/ K were quite lucky as i haven't been able to reproduce that result after 4-5 searches. houdini seems faster but can still take over a minute. SF consistently under 30 seconds. dont know how they do it but i sure hope someone can figure it out!

It takes till depth 31 and 8minutes for me on my notebook

141: Komodo 10.3 64-bit LTC - StockFish 8 MP, StockFish 8 vs Komodo 10.3, Rapid 40m+4 2016
6k1/5p2/2bp1p1b/4q2p/1QP1PpP1/rP3B1P/4K3/2N1R3 b - - 0 1

Analysis by Komodo 10.1 64-bit 4x i5 4200m:

48...Ra8 49.Kd3 Bg7 50.Qd2 f5 51.gxf5 Re8 52.Kc2 Kh7 53.Nd3 Qf6 54.e5 dxe5 55.Rxe5 Rxe5 56.Nxe5 Bxf3 57.Nxf3 Qb2+ 58.Kd1 Qxb3+ 59.Ke2 Qxc4+ 60.Qd3 Qa2+ 61.Qd2 Qa6+ 62.Qd3 Qf6 63.Qe4 Qb2+ 64.Kd1 Bf6 65.Qxf4 Qg2 66.Qe3 Qf1+ 67.Kc2 Qc4+ 68.Kd1 Qd5+ 69.Ke2 Qxf5 70.Qd3 Kg6 71.Nd2 Qxd3+ 72.Kxd3 Kf5 73.Nc4 Be5 74.Ke3 Bc3
-/+ (-0.78) Depth: 30 00:05:44 1296mN
48...Ra8 49.Kd3
-/+ (-0.72 --) Depth: 31 00:05:58 1353mN
48...Ra8 49.Kd3 Bg7
-/+ (-0.78 ++) Depth: 31 00:06:22 1444mN
48...Ra8 49.Kd3
-/+ (-0.72 --) Depth: 31 00:07:06 1615mN
48...d5 49.Qxa3 dxe4
-/+ (-0.87 ++) Depth: 31 00:08:07 1855mN
48...d5 49.Qxa3 dxe4
-/+ (-1.00 ++) Depth: 31 00:08:49 2018mN
48...d5 49.Qxa3 dxe4
-/+ (-1.19 ++) Depth: 31 00:09:32 2185mN
48...d5 49.Qxa3 dxe4
-/+ (-1.47 ++) Depth: 31 00:10:50 2491mN
48...d5 49.Qxa3 dxe4
-+ (-1.89 ++) Depth: 31 00:12:43 2945mN
48...d5 49.cxd5 Bf8 50.Qc4 Qb2+ 51.Kf1 Bb7 52.Re2 Qa1 53.Kg2 Ba6 54.Qc7 Bxe2 55.Nxe2 Qe5 56.Qc8 h4 57.Qc2 Ra1 58.Kf2 Ra5 59.Kg2 Ra3 60.Qd2 Rxb3 61.Qxf4 Rb2 62.Qxe5 fxe5 63.g5 Kg7 64.Bh5 Be7 65.Kf3 Bc5 66.Kg2 Rb3 67.Kh2 Re3 68.Kg2 Kf8 69.Bg4
-+ (-2.07) Depth: 31 00:14:02 3257mN

(Mourik, S'dijk 04.01.2017)

[kgburcham]

[D] 6k1/5p2/2bp1p1b/4q2p/1QP1PpP1/rP3B1P/4K3/2N1R3 b - -

Nalimov 6 men EGTB available - 512 MB cache
Engine: Houdini 5.01 Pro x64-pext (8192 MB)
by Robert Houdart
8 threads used
18/45 0:01 -0.82 48...Ra8 49.Kd3 Bg7 50.Qd2 Ra1 51.Ke2 hxg4 52.hxg4 Bxe4 53.Kf1 Bxf3 54.Rxe5 fxe5 55.Kf2 Bxg4 56.Qxd6 Kh7 57.Qd2 f3 (22.486.822) 22419
18/47 0:02 -0.69 48...Ra8 49.Kd3 Bg7 50.Qd2 Bd7 51.Ke2 hxg4 52.hxg4 Qg5 53.Nd3 Ra3 54.Qxf4 Rxb3 55.Qxg5 fxg5 56.e5 Be6 57.Bd5 Bxg4+ 58.Kd2 Bf5 59.Be4 Bxe4 60.Rxe4 (54.056.221) 22163 TB:2
19/55 0:03 -0.89 48...Ra8 49.Kd3 Bg7 50.Qd2 Ra1 51.Ke2 Bxe4 52.Kf1 Bxf3 53.Rxe5 fxe5 54.Kf2 Be4 55.g5 h4 56.Qc3 Rb1 57.c5 Bf5 58.c6 e4 59.Qc4 Rb2+ 60.Kg1 (85.682.142) 22117 TB:16
20/55 0:04 -0.83 48...Ra8 49.Kd3 Bg7 50.Qd2 Ra1 51.Ke2 Bxe4 52.Kf1 Bxf3 53.Rxe5 fxe5 54.Kf2 Be4 55.g5 h4 56.Qc3 Rb1 57.c5 dxc5 58.Nd3 Rh1 59.Nxe5 Rh2+ 60.Kf1 Bf5 61.Qxc5 Bxh3+ (101.686.961) 22081 TB:18
20/55 0:05 -0.83-- 48...Ra8 49.Kd3 Bg7 50.Qd2 Ra1 51.Ke2 Bxe4 52.Kf1 Bxf3 53.Rxe5 fxe5 54.Kf2 Be4 55.g5 h4 56.Qc3 Rb1 57.c5 dxc5 58.Nd3 Rh1 59.Nxe5 Rh2+ 60.Kf1 Bf5 61.Qxc5 Bxh3+ (111.387.586) 22061 TB:18
20/55 0:05 -1.03++ 48...d5 (116.924.105) 22044 TB:18
20/55 0:05 -1.13++ 48...d5 (125.127.737) 22041 TB:18
20/55 0:06 -1.26++ 48...d5 (133.225.958) 22028 TB:18
20/55 0:07 -1.23 48...d5 49.cxd5 Bf8 50.Qc4 Qb2+ 51.Kf1 Bb7 52.Re2 Qa1 53.Kg2 Ba6 54.Qc7 Bxe2 55.Nxe2 Rxb3 56.Qxf4 h4 57.g5 fxg5 58.Qxg5+ Qg7 59.Qg4 Qxg4+ 60.Bxg4 Bc5 61.Bf3 Rb2 (154.139.810) 21960 TB:18
20/55 0:07 -1.23 48...d5 49.cxd5 Bf8 50.Qc4 Qb2+ 51.Kf1 Bb7 52.Re2 Qa1 53.Kg2 Ba6 54.Qc7 Bxe2 55.Nxe2 Rxb3 56.Qxf4 h4 57.g5 fxg5 58.Qxg5+ Qg7 59.Qg4 Qxg4+ 60.Bxg4 Bc5 61.Bf3 Rb2 (154.731.755) 21953 TB:18
21/55 0:07 -1.30++ 48...d5 (167.193.178) 21924 TB:18
21/55 0:08 -1.36++ 48...d5 (181.667.037) 21720 TB:18
21/55 0:09 -1.45++ 48...d5 (211.062.688) 21729 TB:28
21/55 0:10 -1.37-- 48...d5 49.cxd5 (226.878.164) 21739 TB:32
21/55 0:11 -1.33 48...d5 49.cxd5 Bf8 50.Qc4 Qb2+ 51.Kf1 Bb7 52.Re2 Qa1 53.Kg2 Ba6 54.Qc7 Bxe2 55.Nxe2 Rxb3 56.Qxf4 h4 57.g5 fxg5 58.Qxg5+ Qg7 59.Qxg7+ Bxg7 60.Bg4 Kf8 61.Ng1 Re3 (244.726.928) 21743 TB:35
21/55 0:11 -1.33 48...d5 49.cxd5 Bf8 50.Qc4 Qb2+ 51.Kf1 Bb7 52.Re2 Qa1 53.Kg2 Ba6 54.Qc7 Bxe2 55.Nxe2 Rxb3 56.Qxf4 h4 57.g5 fxg5 58.Qxg5+ Qg7 59.Qxg7+ Bxg7 60.Bg4 Kf8 61.Ng1 Re3 (244.996.236) 21742 TB:35
22/55 0:11 -1.39++ 48...d5 (257.346.355) 21764 TB:36
22/55 0:13 -1.34 48...d5 49.cxd5 Bf8 50.Qc4 Qb2+ 51.Kf1 Bb7 52.Re2 Qa1 53.Kg2 Ba6 54.Qc7 Bxe2 55.Nxe2 Rxb3 56.Qxf4 h4 57.g5 fxg5 58.Qxg5+ Qg7 59.Qxg7+ Bxg7 60.Bg4 Kf8 61.Ng1 Re3 (305.135.484) 21806 TB:46
22/55 0:14 -1.34 48...d5 49.cxd5 Bf8 50.Qc4 Qb2+ 51.Kf1 Bb7 52.Re2 Qa1 53.Kg2 Ba6 54.Qc7 Bxe2 55.Nxe2 Rxb3 56.Qxf4 h4 57.g5 fxg5 58.Qxg5+ Qg7 59.Qxg7+ Bxg7 60.Bg4 Kf8 61.Ng1 Re3 (305.804.980) 21804 TB:46
23/55 0:16 -1.37 48...d5 49.cxd5 Bf8 50.Qc4 Qb2+ 51.Kf1 Bb7 52.Re2 Qa1 53.Kg2 Ba6 54.Qc7 Bxe2 55.Nxe2 Rxb3 56.Qxf4 h4 57.g5 fxg5 58.Qxg5+ Qg7 59.Qxg7+ Bxg7 60.Bg4 Kf8 61.Ng1 Re3 (351.739.532) 21853 TB:54
23/55 0:16 -1.37 48...d5 49.cxd5 Bf8 50.Qc4 Qb2+ 51.Kf1 Bb7 52.Re2 Qa1 53.Kg2 Ba6 54.Qc7 Bxe2 55.Nxe2 Rxb3 56.Qxf4 h4 57.g5 fxg5 58.Qxg5+ Qg7 59.Qxg7+ Bxg7 60.Bg4 Kf8 61.Ng1 Re3 (354.843.406) 21851 TB:54
24/55 0:19 -1.37 48...d5 49.cxd5 Bf8 50.Qc4 Qb2+ 51.Kf1 Bb7 52.Re2 Qa1 53.Kg2 Ba6 54.Qc7 Bxe2 55.Nxe2 Rxb3 56.Qxf4 h4 57.g5 fxg5 58.Qxg5+ Qg7 59.Qxg7+ Bxg7 60.Bg4 Kf8 61.Ng1 Re3 (434.125.372) 21854 TB:89
24/55 0:20 -1.37 48...d5 49.cxd5 Bf8 50.Qc4 Qb2+ 51.Kf1 Bb7 52.Re2 Qa1 53.Kg2 Ba6 54.Qc7 Bxe2 55.Nxe2 Rxb3 56.Qxf4 h4 57.g5 fxg5 58.Qxg5+ Qg7 59.Qxg7+ Bxg7 60.Bg4 Kf8 61.Ng1 Re3 (447.480.589) 21854 TB:91
24/55 0:26 -1.38 48...d5 49.cxd5 Bf8 50.Qc4 Qb2+ 51.Kf1 Bb7 52.Re2 Qa1 53.Kg2 Ba6 54.Qc7 Bxe2 55.Nxe2 Rxb3 56.Qxf4 h4 57.g5 fxg5 58.Qxg5+ Qg7 59.Qxg7+ Bxg7 60.Bg4 Kf8 61.Ng1 Re3 (585.678.008) 21834 TB:158
24/55 0:27 -1.38 48...d5 49.cxd5 Bf8 50.Qc4 Qb2+ 51.Kf1 Bb7 52.Re2 Qa1 53.Kg2 Ba6 54.Qc7 Bxe2 55.Nxe2 Rxb3 56.Qxf4 h4 57.g5 fxg5 58.Qxg5+ Qg7 59.Qxg7+ Bxg7 60.Bg4 Kf8 61.Ng1 Re3 (591.812.678) 21830 TB:158
25/57 0:36 -1.44++ 48...d5 (801.613.804) 21811 TB:350
25/57 0:38 -1.50++ 48...d5 (832.347.017) 21826 TB:387
25/57 0:40 -1.59++ 48...d5 (877.095.433) 21832 TB:429
25/59 0:45 -1.65 48...d5 49.cxd5 Bf8 50.Qc4 Qb2+ 51.Kf1 Bb7 52.Re2 Qa1 53.Kg2 Ba6 54.Qc7 Bxe2 55.Nxe2 Rxb3 56.Qxf4 h4 57.g5 fxg5 58.Qxg5+ Qg7 59.Qg4 Qxg4+ 60.Bxg4 Bc5 61.e5 Re3 (999.775.225) 21848 TB:603
25/59 0:48 -1.65 48...d5 49.cxd5 Bf8 50.Qc4 Qb2+ 51.Kf1 Bb7 52.Re2 Qa1 53.Kg2 Ba6 54.Qc7 Bxe2 55.Nxe2 Rxb3 56.Qxf4 h4 57.g5 fxg5 58.Qxg5+ Qg7 59.Qg4 Qxg4+ 60.Bxg4 Bc5 61.e5 Re3 (1.049.966.272) 21836 TB:622

[yanquis1972]

yes, that aligns w/ my results. assume its just CPU + faster search in 10.3, tho i also use 4GB hash + 512MB transposition table.


1.40 1...d5 (depth 33, 1/41), 1.5G nodes (15.6M nps), 74.9K tbhits
0.00: -1.95/3 1...Ra8 2.gxh5 Bg7
0.00: -0.96/4 1...hxg4 2.Qxa3 gxf3+ 3.Kxf3 Qc3+ 4.Kf2 Qg3+ 5.Kf1
0.00: -1.26/5 1...Ra8 2.gxh5 Qc5 3.Qc3 Bg7
0.00: -1.04/6 1...hxg4 2.Qxa3 gxf3+ 3.Kxf3 Qc3+ 4.Ke2 Kh7 5.Kd1
0.00: -1.08/7 1...hxg4 2.hxg4 Ra1 3.Qd2 Bxe4 4.Kf1 Bxf3
0.00: -0.94/8 1...hxg4 2.hxg4 Ra1 3.Qd2 Bg5 4.Nd3 Rxe1+ 5.Qxe1 Qd4 6.Qd2 Bxe4
0.00: -0.91/9 1...hxg4 2.hxg4 Ra1 3.Kf1 Bg5 4.Nd3 Rxe1+ 5.Qxe1 Qd4 6.Nb4 Bb7 7.Nd5 Qd3+ 8.Qe2
0.00: -0.73/10 1...hxg4 2.hxg4 Ra8 3.Kf1 Bg5 4.Qd2 Rb8 5.Re2 Qc5 6.Kg2 Kg7
0.00: -0.63/11 1...hxg4 2.hxg4
0.00: -0.49/11 1...Ra6 2.Qd2
0.00: -0.60/11 1...hxg4 2.hxg4 Ra1 3.Qd2 Bg5 4.Nd3 Rxe1+ 5.Kxe1 Qd4 6.Nf2 Qa1+ 7.Ke2 Qa3 8.Qc2 Qc5 9.Qd3 Bh4 10.Nd1
0.00: -0.97/12 1...hxg4 2.hxg4 Ra1 3.Qd2 Bg5 4.Nd3 Rxe1+ 5.Kxe1 Qa1+ 6.Qd1 Qd4 7.Kf1 Bh4 8.Qe2 Bg3 9.Kg2 Kf8 10.Nf2 Qb6
0.00: -0.96/13 1...hxg4 2.hxg4 Ra1 3.Qd2 Bg5 4.Nd3 Rxe1+ 5.Kxe1 Qa1+ 6.Qd1 Qd4 7.Kf1 Bh4 8.Qe2 Bg3 9.Kg2 Kf8 10.Nf2 Qb6 11.Qd2 Bxf2
0.00: -1.25/13 1...Ra1 2.Qd2 hxg4 3.hxg4 Bg5 4.Nd3 Rxe1+ 5.Kxe1 Qa1+ 6.Qd1 Qd4 7.Nf2 Qe3+ 8.Kf1 Bh4 9.Nh3 Bxe4 10.Bxe4 Qxe4
0.00: -0.72/14 1...Ra1 2.Qd2 hxg4 3.hxg4 Bg5 4.Nd3 Qd4 5.Rxa1 Qxa1 6.Nf2 Qb1 7.Qd1 Qb2+ 8.Kf1 Bh4 9.Nh3 Qe5 10.Nf2 Bg3
0.00: -0.55/14 1...hxg4 2.hxg4
0.00: -0.61/14 1...Ra1 2.Qd2 hxg4 3.hxg4 Bg5 4.Nd3 Qd4 5.Rxa1 Qxa1 6.Qd1 Qd4 7.Kf1 Bh4 8.Qe2 Bg3 9.Kg2 Kg7 10.Kh3 Bb7 11.Kg2
0.00: -0.54/15 1...Ra1 2.Qd2
0.00: -0.51/15 1...Ra6 2.Qd2
0.00: -0.64/15 1...Ra1 2.Qd2 hxg4 3.hxg4 Bg5 4.Nd3 Qd4 5.Rxa1 Qxa1 6.Qd1 Qd4 7.Kf1 Bh4 8.Qe2 Bg3 9.Kg2 Bb7 10.Nb4 Qc3 11.Nd5 Bxd5
0.00: -0.52/16 1...Ra1 2.Qd2
0.00: -0.65/16 1...hxg4 2.hxg4
0.00: -0.48/16 1...Ra8 2.Qd2 hxg4 3.hxg4 Bxe4 4.Kf1 Bxf3 5.Rxe5 dxe5 6.Nd3 Ra1+ 7.Nc1 Bxg4 8.c5 Kg7 9.Qb2 Ra7 10.c6 f3 11.Qc3 Ra8 12.Kf2
0.00: -0.36/16 1...Ra1 2.Qd2
0.00: -0.38/16 1...hxg4 2.hxg4 Ra1 3.Qd2 Qc5 4.Kf1 Qa3 5.Qc3 Bg5 6.Nd3 Rxe1+ 7.Nxe1 Qa2 8.Nc2 Kg7 9.Ke2 Bh4 10.Kd2 Bd7 11.Kc1 Bg5 12.Kd2
0.00: -0.56/17 1...hxg4 2.hxg4 Ra8 3.Qd2 Bxe4 4.Kf1 Bxf3 5.Rxe5 dxe5 6.Nd3 Ra1+ 7.Nc1 Bxg4 8.c5 Bf5 9.Kf2 Bg5 10.Qc3 Rb1 11.c6 f3 12.Qxf3 Be6 13.Nd3 Rxb3
0.00: -0.64/18 1...hxg4 2.hxg4 Ra8 3.Qd2 Bxe4 4.Kf1 Bxf3 5.Rxe5 dxe5 6.Nd3 Ra1+ 7.Nc1 Bxg4 8.c5 Bf5 9.Kf2 Rb1 10.Qc3 Bg5 11.c6 f3 12.Qxf3 Be6 13.Nd3 Rxb3 14.c7
0.01: -0.41/19 1...hxg4 2.hxg4 Ra8 3.Kd3 Bg7 4.Qd2 Bd7 5.Ke2 Qg5 6.Nd3 Be6 7.Qxf4 Ra2+ 8.Kf1 Qh4 9.Re2 Qh3+ 10.Kf2 Ra3 11.Qxd6 Rxb3 12.Rb2 Rxb2+ 13.Nxb2 Bxg4
0.01: -0.42/19 1...Ra8 2.Kd3 Bg7 3.Qd2 hxg4 4.hxg4 Ra3 5.Ke2 Bh6 6.Nd3 Qd4 7.Nc1 Qc5 8.Kf1 Bg5 9.Rd1 Ra1 10.Nd3 Qd4 11.Rxa1 Qxa1+ 12.Qe1 Qa2 13.Qd1 Bh4 14.Qe2
0.01: -0.35/20 1...Ra8 2.Kd3
0.01: -0.59/20 1...hxg4 2.hxg4 Ra1 3.Qd2 Qc5 4.Kf1 Bg5 5.Nd3 Qd4 6.Rxa1 Qxa1+ 7.Qd1 Qc3 8.Kg2 Bd7 9.Nf2 Bh4 10.Qxd6 Qb2 11.Qb6 Kg7 12.Bd1 Qc3 13.Bf3 Be6
0.02: -0.58/21 1...hxg4 2.hxg4 Ra1 3.Qd2 Qc5 4.Kf1 Bg5 5.Nd3 Qd4 6.Rxa1 Qxa1+ 7.Qe1 Qd4 8.Nb4 Bb7 9.Qd1 Qc3 10.Nd3 Bc6 11.Kg2 Bd7 12.Nf2 Bh4 13.Qxd6 Qb2
0.02: -0.58/22 1...hxg4 2.hxg4 Ra1 3.Qd2 Qc5 4.Kf1 Bg5 5.Nd3 Qd4 6.Rxa1 Qxa1+ 7.Qe1 Qd4 8.Nb4 Bb7 9.Qd1 Qc3 10.Nd3 Bc6 11.Kg2 Bd7 12.Nf2 Bh4 13.Qxd6 Qb2 14.Qb6 Kg7 15.Kf1
0.04: -0.51/23 1...hxg4 2.hxg4 Ra1 3.Qd2 d5 4.Nd3 Rxe1+ 5.Qxe1 Qe8 6.cxd5 Bxd5 7.Qb4 Be6 8.Qc3 Bg5 9.e5 Kg7 10.Nc5 Qc8 11.b4 Bxg4 12.exf6+ Bxf6 13.Bxg4 Qxg4+ 14.Qf3 Qf5 15.Qe4 Qh5+ 16.Qf3 Qe5+ 17.Qe4 Qg5 18.Qf3 Bd4 19.Qe4 Qh5+
0.05: -0.45/24 1...hxg4 2.hxg4
0.05: -0.48/24 1...Ra1 2.Qd2 hxg4 3.hxg4 d5 4.Nd3 Rxe1+ 5.Qxe1 Qe8 6.cxd5 Bxd5 7.Qb4 Be6 8.Qd4 Bg7 9.Qb4 Bf8 10.Qc3 Qb5 11.e5 fxe5 12.Qxe5 Qxe5+ 13.Nxe5 Kg7 14.Nd3 Bxb3 15.Nxf4 Kf6 16.Kd3 Ke5 17.Ne2 Bc5
0.06: -0.36/25 1...Ra1 2.Qd2
0.08: -0.43/25 1...hxg4 2.hxg4 Ra1 3.Qd2 d5 4.Nd3 Rxe1+ 5.Qxe1 Qe6 6.cxd5 Bxd5 7.Nc5 Qe7 8.Qc3 Bc6 9.Qc4 Qe8 10.Nd3 Bg5 11.Kd2 Bd7 12.Qd4 Qc8 13.Qc4 Qa8 14.Nc5 Qa2+ 15.Kc3 Qf2 16.Nxd7 Qxf3+ 17.Qd3 Qg3 18.b4
0.08: -0.55/25 1...Qd4 2.Qd2 Qa7 3.Kf1 hxg4 4.hxg4 Bg5 5.Kg2 Ra1 6.Qb2 Bh4 7.Re2 Bd7 8.Rd2 Be6 9.Rd1 Qe3 10.Rf1 Ra5 11.Qe2 Bg5 12.Rd1 Ra1 13.Nd3 Ra6 14.Nc1 Kf8 15.c5
0.13: -0.67/26 1...Qd4 2.Kf1 hxg4 3.hxg4 Qb2 4.Qxd6 Qc3 5.Qd3 Rxb3 6.Rd1 Ra3 7.Qxc3 Rxc3 8.Kf2 Rxc4 9.Ne2 Kh7 10.Nd4 Bb7 11.Rb1 Bc8 12.Nf5 Bf8 13.Rh1+ Kg6 14.Rh8 Rc2+ 15.Be2 Bxf5 16.gxf5+ Kg7
0.20: -0.55/27 1...Qd4 2.Kf1 hxg4 3.hxg4 Qb2 4.Qxd6 Qc3 5.Qd3 Rxb3 6.Rd1 Qxd3+ 7.Rxd3 Rb1 8.Rd1 Ba4 9.Re1 Rb4 10.e5 Bg5 11.Nd3 Rxc4 12.exf6 Rc3 13.Rc1 Rxc1+ 14.Nxc1 Kh7 15.Nd3 Kg6 16.Bd5 Bb5 17.Be4+ Kh6 18.Ke2 Bxf6 19.Kf3 Kg5 20.Nxf4 Bd7
0.22: -0.65/28 1...Qd4 2.Kf1 hxg4 3.hxg4 Qb2 4.Qxd6 Qc3 5.Qd3 Rxb3 6.Rd1 Qxd3+ 7.Rxd3 Rb1 8.Rd1 Ba4 9.Re1 Rb4 10.e5 Rxc4 11.exf6 Bg5 12.Nd3 Rc3 13.Rc1 Rxc1+ 14.Nxc1 Kh7 15.Nd3 Kg6 16.Bd5 Kxf6 17.Ke2 Ke7 18.Nc5 Kd6 19.Nxa4 Kxd5 20.Kf3
0.23: -0.65/29 1...Qd4 2.Kf1 hxg4 3.hxg4 Qb2 4.Qxd6 Qc3 5.Qd3 Rxb3 6.Rd1 Qxd3+ 7.Rxd3 Rb1 8.Rd1 Ba4 9.Re1 Rb4 10.e5 Rxc4 11.exf6 Bg5 12.Nd3 Rc3 13.Rc1 Rxc1+ 14.Nxc1 Kh7 15.Nd3 Kg6 16.Bd5 Kxf6 17.Ke2 Ke7 18.Nc5 Kd6 19.Nxa4 Kxd5 20.Kf3
0.29: -0.58/30 1...Qd4 2.Kf1 hxg4 3.hxg4 Qb2 4.Qxd6 Qc3 5.Qd3 Rxb3 6.Rd1 Qxd3+ 7.Rxd3 Rb1 8.Rd1 Ba4 9.Re1 Rb4 10.e5 Rxc4 11.exf6 Bg5 12.Nd3 Rc3 13.Rc1 Rxc1+ 14.Nxc1 Kh7 15.Nd3 Kg6 16.Bd5 Kxf6 17.Ke2 Ke7 18.Nc5 Kd6 19.Nxa4 Kxd5 20.Kf3 Kd4 21.Nb6 Kc5
0.38: -0.53/31 1...Qd4 2.Kf1 hxg4 3.hxg4 Qb2 4.Qxd6 Qc3 5.Qd3 Rxb3 6.Rd1 Qxd3+ 7.Rxd3 Rb1 8.Rd1 Ba4 9.Re1 Rb4 10.e5 Rxc4 11.exf6 Bg5 12.Nd3 Rc3 13.Rc1 Rxc1+ 14.Nxc1 Kh7 15.Nd3 Kg6 16.Ke2 Bb5 17.Be4+ Kxf6 18.Kf3 Ba4 19.Nxf4 Ke5 20.Nh3 Bd1+ 21.Kg3 Be7 22.Bf3 Bc2 23.Nf2
0.52: -0.61/32 1...Qd4 2.Kf1 hxg4 3.hxg4 Qb2 4.Qxd6 Qc3 5.Qd3 Rxb3 6.Rd1 Ra3 7.Qxc3 Rxc3 8.Kf2 Rxc4 9.Ne2 Bg5 10.Nd4 Bb7 11.Rd2 Rc3 12.Nb5 Rc1 13.Nd4 Bc8 14.Bd1 Bh4+ 15.Kg2 Be1 16.Rc2 Rxc2+ 17.Nxc2 Bc3 18.Kf3 Kg7 19.Kxf4 Kg6 20.Ke3 Kg5 21.Nd4 Bd7
1.05: -0.60/33 1...Qd4 2.Kf1 Qb2 3.Qxd6 Qc3 4.Qd3 Rxb3 5.Rd1 Ra3 6.Qxc3 Rxc3 7.Kf2 hxg4 8.hxg4 Rxc4 9.Ne2 Rc2 10.Rd8+ Bf8 11.Kg1 Bxe4 12.Nd4 Rc1+ 13.Kf2 Bg6 14.Bd5 Kg7 15.Kf3 Rf1+ 16.Ke2 Rg1 17.Kf3 Bb4 18.Kxf4 Rf1+ 19.Bf3 Bd2+ 20.Kg3 Bc3 21.Kf4 Kh6 22.Nf5+ Bxf5 23.gxf5 Be5+ 24.Kg4 Rg1+ 25.Kh4
1.32: -0.62/33 1...Ra8 2.Kd3
1.40: -1.02/33 1...d5 2.Qxa3 dxe4

and a lucky search:


0.20 1...d5 (depth 29, 1/41), 347M nodes (16.6M nps), 10.1K tbhits
0.00: -1.95/3 1...Ra8 2.gxh5 Bg7
0.00: -1.46/4 1...Ra8 2.Qd2 hxg4 3.hxg4
0.00: -1.90/5 1...Ra8 2.Qd2 hxg4 3.hxg4 Re8
0.00: -1.24/6 1...Ra1 2.Kf1 hxg4 3.hxg4 Bf8 4.Qd2
0.00: -1.07/7 1...Ra1 2.Kf1 hxg4 3.hxg4 Bf8 4.Qd2 Bg7
0.00: -0.87/8 1...Ra1 2.Kf1 hxg4 3.hxg4 Kg7 4.Qd2 Kh7 5.b4
0.00: -0.91/9 1...Ra1 2.Kf1 Bg5 3.gxh5 Bh4 4.Rd1 Bxe4 5.Bxe4 Qxe4 6.Qxd6 Qf3+
0.00: -0.73/10 1...Ra8 2.Qd2 hxg4 3.hxg4 Re8 4.Kf1 Bg5 5.Kg2 Kg7 6.b4 Qe6
0.00: -0.53/11 1...Ra8 2.Qd2 hxg4 3.hxg4 Rb8 4.Kf1 Bg5 5.Rd1 Bxe4 6.Re1 Bxf3 7.Rxe5 dxe5 8.c5 Bxg4
0.00: -0.57/12 1...Ra8 2.Qd2 hxg4 3.hxg4 Re8 4.Kf1 Kg7 5.Rd1 Bxe4 6.Re1 Bxf3 7.Rxe5 dxe5 8.b4 e4 9.Qd7 Re6
0.00: -0.67/12 1...hxg4 2.hxg4 Ra8 3.Qd2 Re8 4.Kf1 Bg5 5.Rd1 Bxe4 6.Re1 f5 7.gxf5 Qxf5 8.Rxe4 Rxe4
0.00: -0.65/13 1...hxg4 2.hxg4 Ra8 3.Qd2 Rb8 4.Kf1 Bg5 5.Rd1 Bxe4 6.Re1 Bxf3 7.Rxe5 dxe5 8.b4 Kg7 9.Nb3 Bxg4 10.b5
0.00: -0.67/13 1...Ra8 2.Qd2 hxg4 3.hxg4 Rb8 4.Kf1 Bg5 5.Rd1 Bxe4 6.Re1 Bxf3 7.Rxe5 dxe5 8.b4 Kg7 9.Nb3 Rh8
0.00: -0.70/14 1...Ra8 2.Qd2 hxg4 3.hxg4 Bxe4 4.Kf1 Bxf3 5.Rxe5 dxe5 6.b4 Kg7 7.Qd7 e4 8.Qd4 Bg5 9.b5 Rh8 10.Qg1 e3
0.00: -0.63/15 1...Ra8 2.Qd2
0.00: -0.63/15 1...hxg4 2.hxg4 Ra8 3.Qd2 Re8 4.Kf1 Bg5 5.Rd1 Bxe4 6.Re1 Bxf3 7.Rxe5 dxe5 8.Nd3 e4 9.Nxf4 e3 10.Qh2 Ra8 11.Ng2 Ra1+ 12.Ne1
0.00: -0.90/15 1...Ra8 2.Qd2 Re8 3.Kf1 hxg4 4.hxg4 Bg5 5.Rd1 Bxe4 6.Re1 Bxf3 7.Rxe5 dxe5 8.Nd3 e4 9.Nxf4 e3
0.00: -0.46/16 1...Ra8 2.Qd2 hxg4 3.hxg4 Qc5 4.Kf1 Bg5 5.Rd1 Ra1 6.Nd3 Rxd1+ 7.Qxd1 Qb6 8.Kg2 Bd7 9.Kf1 Kg7 10.Kg2 Qe3 11.Nf2 Be6 12.Nh3
0.00: -0.46/17 1...Ra8 2.Qd2
0.00: -0.62/17 1...hxg4 2.hxg4 Ra1 3.Qd2 Qc5 4.Kf1 Qa3 5.Rd1 Bg5 6.Qc2 Kg7 7.Ne2 Ra2 8.Qc3 Qa8 9.Nd4 Bxe4 10.Re1 Bxf3 11.Qxf3 Qxf3+ 12.Nxf3 Rb2
0.00: -0.41/18 1...hxg4 2.hxg4
0.00: -0.54/18 1...Qd4 2.Qd2 Qc5 3.Kf1 hxg4 4.hxg4 Ba4 5.Qf2 Bxb3 6.Qxc5 dxc5 7.Nxb3 Rxb3 8.Kg2 Bg7 9.Kf2 Rc3 10.Be2 Re3 11.Rd1 Bf8 12.Rd5 Rxe4 13.Rf5 Kg7 14.Bf3
0.00: -0.66/19 1...Qd4 2.Qd2 Qc5 3.Rd1 hxg4 4.hxg4 Bxe4 5.Qd4 Bc2 6.Rd2 Bxb3 7.Nxb3 Rxb3 8.Qxc5 dxc5 9.Rd5 Bf8 10.Rf5 Kg7 11.Rxf4 Bd6 12.Rf5 Be5 13.Bd5 Rg3 14.Bf3 Rh3
0.00: -0.62/20 1...Qd4 2.Qd2 Qc5 3.Rd1 hxg4 4.hxg4 Bxe4 5.Qd4 Bc2 6.Rd2 Bxb3 7.Nxb3 Rxb3 8.Qxc5 dxc5 9.Rd5 Bf8 10.Rf5 Kg7 11.Rxf4 Bd6 12.Rf5 Be5 13.Bd5 Bd4 14.Rh5 Rg3 15.Rh4 Be5
0.01: -0.52/21 1...Qd4 2.Qd2 Qc5 3.Rd1 hxg4 4.hxg4 Bxe4 5.Qd4 Bc2 6.Rd2 Bxb3 7.Nxb3 Rxb3 8.Qxc5 dxc5 9.Rd5 Bf8 10.Rf5 Kg7 11.Rxf4 Bd6 12.Rf5 Be5 13.Bd5 Rg3 14.Bf3 Kf8 15.Kd3 Ke7 16.Ke4
0.01: -0.46/22 1...Qd4 2.Qd2
0.01: -0.45/22 1...hxg4 2.hxg4
0.02: -0.44/22 1...Ra1 2.Qd2 hxg4 3.hxg4 Bg5 4.Nd3 Qd4 5.Rxa1 Qxa1 6.Nf2 Qb1 7.Qd3 Qa2+ 8.Kf1 Bh4 9.Nd1 Bd7 10.Be2 Qa3 11.Qf3 Be6 12.Nf2 Bg3 13.Kg2 Qb2 14.Nd3 Qd2 15.Nf2 Kg7
0.03: -0.48/23 1...Ra1 2.Qd2 hxg4 3.hxg4 Bg5 4.Nd3 Qd4 5.Rxa1 Qxa1 6.Nf2 Qb1 7.Qd3 Qa2+ 8.Kf1 Bh4 9.Nd1 Bd7 10.Be2 Qa3 11.Qf3 Kg7 12.Nc3 Qxb3 13.Nd5 Qb1+ 14.Kg2 Bg5 15.Nxf4
0.03: -0.62/23 1...hxg4 2.hxg4 Qd4 3.Kf1 Qb2 4.Qxd6 Qc3 5.Qd3 Rxb3 6.Rd1 Qxd3+ 7.Rxd3 Rb1 8.Rd1 Ba4 9.Re1 Rb4 10.c5 Rc4 11.Ne2 Rxc5 12.Nd4 Rc4 13.Nf5 Bf8 14.Rb1 Bc5 15.Ke2 Rc2+ 16.Kd3 Rf2 17.Kc4 Be3 18.Ra1
0.04: -0.61/24 1...hxg4 2.hxg4 Qd4 3.Qd2 Qa7 4.Kf1 Bg5 5.Kg2 Ra1 6.Qb2 Kg7 7.Rh1 Qa8 8.Rh5 Kg8 9.Kh2 Bb7 10.Rh3 Qa5 11.Kg2 Qe5 12.Qc2 Qd4 13.Rh1 Qe3 14.Qf2 Kf8 15.Qxe3 fxe3 16.Kg3 Ke7 17.Ne2 Rxh1
0.04: -0.61/25 1...hxg4 2.hxg4 Qd4 3.Qd2 Qa7 4.Kf1 Bg5 5.Kg2 Ra1 6.Qb2 Kg7 7.Rh1 Qa8 8.Rh5 Kg8 9.Kh2 Bb7 10.Rh3 Qa5 11.Kg2 Qe5 12.Qc2 Qd4 13.Rh1 Qe3 14.Qf2 Kf8 15.Qxe3 fxe3 16.Kg3 Ke7 17.Ne2 Rxh1
0.06: -0.54/26 1...hxg4 2.hxg4
0.06: -0.65/26 1...Qd4 2.Qd2 Qa7 3.Kf1 hxg4 4.hxg4 Bg5 5.Kg2 Ra1 6.Qb2 Bh4 7.Rf1 Qa8 8.Rh1 Bxe4 9.Qe2 d5 10.cxd5 Bxd5 11.Qd3 Bxf3+ 12.Qxf3 Qa3 13.Ne2 Rxh1 14.Kxh1 Bg5 15.Kg2 Qb2 16.Kh3 Qe5 17.Kg2 Kf8 18.b4 Qb2 19.b5 Qxb5 20.Nxf4 Qb1 21.Qa8+
0.08: -0.69/27 1...Qd4 2.Kf1 hxg4 3.hxg4 Qb2 4.Qxd6 Qc3 5.Qd3 Rxb3 6.Rd1 Qxd3+ 7.Nxd3 Rc3 8.Kf2 Rxc4 9.Rc1 Rxc1 10.Nxc1 Kg7 11.Nd3 Bd7 12.Be2 Kg6 13.Kf3 Kg5 14.Nxf4 Bf8 15.Nh3+ Kh4 16.Nf2 Be6 17.Bd3 Bc5 18.Bb5 Bd6 19.Be8 Be5 20.Nd3
0.11: -0.63/28 1...Qd4 2.Kf1
0.19: -1.39/28 1...d5 2.Qxa3 dxe4 3.Qa7 hxg4 4.hxg4 exf3+ 5.Kf1 Qc3 6.Qc5 Qd2 7.Qf2 Qd7 8.b4 Bg5 9.b5 Qxg4 10.Qh2 f2 11.Re2 f3 12.bxc6 Qxc4 13.Qxf2 fxe2+ 14.Nxe2 Qxc6 15.Ng3 Bh4 16.Qf4 Qb5+ 17.Ne2 Bg5 18.Qe4 f5 19.Qg2 Qb1+ 20.Kf2 f6 21.Qc6 Kf7 22.Qd7+ Kg6
0.20: -1.45/29 1...d5 2.Qxa3 dxe4

meanwhile houdini with a clean hash generally seems to take about 20 seconds to clear d21 vs kgburcham's machine.

[kgburcham]

[D] 6k1/5p2/2bp1p1b/4q2p/1QP1PpP1/rP3B1P/4K3/2N1R3 b - -

Engine: Komodo 10 64-bit (8192 MB)
by Don Dailey, Larry Kaufman, Mark Lefler
Threads now set to 8

30.01 1:15 -0.80 48...Ra8 49.Kd3 Bg7 50.Qd2 Re8 51.Kc2 f5 52.gxf5 Kh7 53.h4 Qa1 54.Kd3 Bf6 55.Ne2 Qe5 56.Nc3 Qc5 57.Kc2 Be5 58.Bxh5 Rg8 59.Bf3 Rg3 60.Rf1 Qa5 61.Na4 Qa8 (1.377.501.121) 18255
30.19 1:25 -1.21++ 48...d5 49.Qxa3 dxe4 (1.550.974.683) 18225
30.01 1:53 -1.40 48...d5 49.cxd5 Bf8 50.Qc4 Bb7 51.Qc2 Bxd5 52.gxh5 Be6 53.Rd1 Bxh3 54.Qd2 Kh7 55.Qd5 Be6 56.Qxe5 fxe5 57.Nd3 Bxb3 58.Rc1 Bg7 59.Nc5 Ba2 60.Nd3 f6 61.Rc7 Be6 (2.064.710.471) 18220
31.01 2:02 -1.47++ 48...d5 49.cxd5 Bf8 (2.242.966.420) 18271
31.01 2:14 -1.54++ 48...d5 49.cxd5 Bf8 (2.453.735.108) 18280
31.01 2:20 -1.47-- 48...d5 49.cxd5 (2.572.119.697) 18316
31.01 2:25 -1.55++ 48...d5 49.cxd5 Bf8 (2.662.086.165) 18326
31.01 2:35 -1.43-- 48...d5 49.cxd5 (2.850.201.650) 18335
31.01 2:38 -1.60++ 48...d5 49.cxd5 Bf8 (2.909.243.899) 18345
31.01 2:42 -1.47 48...d5 49.cxd5 Bf8 50.Qc4 Bb7 51.Qc2 Bxd5 52.Rd1 Be6 53.Kf1 Kg7 54.Kg2 Qg5 55.Kh2 Bc5 56.Qg2 h4 57.Qe2 Be3 58.Qb2 Ra6 59.Nd3 Qb5 60.e5 Bxb3 61.exf6+ Kh6 (2.987.448.430) 18344

[Lyudmil Tsvetkov]

Really nice win from a SF8 vs K103 match by Hurnavich at 40/4 LTC
(http://rybkaforum.net/cgi-bin/rybkaforu ... ?tid=31923)
Game 2 shows the black win by SF8 with a quadruple pawn and a rook sac

[D] 6k1/5p2/2bp1p1b/4q2p/1QP1PpP1/rP3B1P/4K3/2N1R3 b - - 0 48
d5! with a surprisingly winning rook sac, SF8 spots this really fast Houdini takes longer
and Komodo takes >5 minutes

and the quadruple winning pawns position
[D] 6k1/Q4p2/2bq1p1b/7P/2P2p2/1P3p1P/8/2N1RK2 b - - 0 52


[pgn]
[Event "StockFish 8 vs Komodo 10.3, Rapid 40m+4"]
[Site "Hurnavich-PC"]
[Date "2016.12.31"]
[Round "2"]
[White "Komodo 10.3 64-bit LTC"]
[Black "StockFish 8 MP"]
[Result "0-1"]
[ECO "B96"]
[Annotator "0.05;0.20"]
[PlyCount "112"]
[EventDate "2016.??.??"]
[TimeControl "2400+4"]

{AMD Phenom(tm) II X6 1100T Processor 3625 MHz W=30.8 plies; 8,410kN/s; 6,495,
173 TBAs B=30.7 plies; 8,306kN/s; 3,707,636 TBAs} 1. e4 c5 2. Nf3 d6 3. d4 cxd4
4. Nxd4 Nf6 5. Nc3 a6 6. Bg5 Nbd7 7. f4 e6 8. Qe2 Be7 9. O-O-O Qc7 10. g4 b5
11. a3 {Both last book move} h6 {[%eval 20,29] 108} 12. Bh4 {[%eval 5,29] 82}
Bb7 {[%eval 11,29] [%emt 0:00:43]} 13. Kb1 {[%eval 19,31] 114 (f5)} Rc8 {
[%eval 0,31] [%emt 0:00:27]} 14. Bg2 {[%eval 6,31] 116} Qc4 {[%eval 0,28]
[%emt 0:00:51]} 15. Qe1 {[%eval 0,31] 121 (h3)} b4 {[%eval -32,29] [%emt 0:00:
28]} 16. axb4 {[%eval -6,29] [%emt 0:00:28]} Qxb4 {[%eval -17,28] [%emt 0:00:
18]} 17. Nb3 {[%eval 0,32] 134 (Bxf6)} Nc5 {[%eval 0,30] 125} 18. Rd4 {[%eval
-6,30] [%emt 0:00:39]} Qb6 {[%eval -13,33] [%emt 0:00:59]} 19. Nxc5 {[%eval -6,
30] [%emt 0:00:31]} Qxc5 {[%eval -12,31] [%emt 0:00:26]} 20. Rd3 {[%eval 0,29]
[%emt 0:00:37]} a5 {[%eval -18,32] 85 (Rb8)} 21. Qd2 {[%eval 0,33] 60} Ba6 {
[%eval -2,35] 338} 22. Bxf6 {[%eval 0,36] 84} gxf6 {[%eval -27,30] [%emt 0:00:
38]} 23. Rd4 {[%eval 0,33] [%emt 0:00:47] (Na4)} Rb8 {[%eval -27,30] [%emt 0:
00:44]} 24. b3 {[%eval 0,34] [%emt 0:00:51] (Nd1)} Rb4 {[%eval -36,31] [%emt 0:
00:43] (Bc8)} 25. Rxb4 {[%eval 0,34] 60} axb4 {[%eval -16,34] 83} 26. Na2 {
[%eval 0,33] [%emt 0:00:22]} O-O {[%eval -37,31] [%emt 0:00:07] (Bb7)} 27. Nxb4
{[%eval -6,35] 142} Bb5 {[%eval -44,32] [%emt 0:00:41] (Ra8)} 28. Rd1 {[%eval
-27,32] 93} Ra8 {[%eval -46,31] [%emt 0:00:11]} 29. Qd4 {[%eval -14,32] [%emt
0:00:36]} Qc7 {[%eval -57,34] [%emt 0:00:54]} 30. Nd3 {[%eval -29,33] 75} e5 {
[%eval -41,33] [%emt 0:00:18]} 31. Qb2 {[%eval -34,31] [%emt 0:00:21]} Qa7 {
[%eval -40,34] 140} 32. Nc1 {[%eval -31,32] [%emt 0:00:44]} exf4 {[%eval -35,
33] [%emt 0:00:53]} 33. Qd4 {[%eval -30,32] 70} Qa5 {[%eval -44,33] [%emt 0:00:
11]} 34. c4 {[%eval -29,32] 82} Bc6 {[%eval -50,30] [%emt 0:00:28]} 35. Kc2 {
[%eval -36,29] [%emt 0:00:20] (Rf1)} Bf8 {[%eval -33,31] 128 (Qe5)} 36. Rd3 {
[%eval -25,30] 102} Re8 {[%eval -41,32] 64} 37. Rd2 {[%eval -28,28] [%emt 0:00:
17]} Qa8 {[%eval -47,29] [%emt 0:00:24]} 38. h3 {[%eval -35,31] 74 (Re2)} Re6 {
[%eval -42,29] [%emt 0:00:48] (Re5)} 39. Re2 {[%eval -21,30] [%emt 0:00:26]}
Bg7 {[%eval -58,30] [%emt 0:00:30]} 40. Qd3 {[%eval -33,29] [%emt 0:00:23]} h5
{[%eval -60,29] [%emt 0:00:07]} 41. Kd1 {[%eval -35,30] [%emt 0:00:29]} Re7 {
[%eval -36,32] 142 (hxg4)} 42. Rd2 {[%eval -36,32] [%emt 0:00:47]} Re8 {[%eval
-54,29] [%emt 0:00:33]} 43. Re2 {[%eval -46,34] 128 (Bf3)} Qa5 {[%eval -80,30]
[%emt 0:00:37] (hxg4)} 44. Qd2 {[%eval -44,32] [%emt 0:00:57]} Qe5 {[%eval -85,
29] [%emt 0:00:38]} 45. Bf3 {[%eval -37,30] [%emt 0:00:33]} Ra8 {[%eval -68,31]
62} 46. Re1 {[%eval -57,29] [%emt 0:00:16] (Ke1)} Ra3 {[%eval -94,29] [%emt 0:
00:16]} 47. Ke2 {[%eval -58,31] [%emt 0:00:33]} Bh6 {[%eval -92,30] [%emt 0:00:
21]} 48. Qb4 {[%eval -71,30] [%emt 0:00:31] (Kf1)} d5 {[%eval -157,27] [%emt 0:
00:32] (Qd4)} 49. Qxa3 {[%eval -201,30] [%emt 0:00:41] (cxd5)} dxe4 {[%eval
-298,30] [%emt 0:00:20]} 50. Qa7 {[%eval -304,30] [%emt 0:00:33]} exf3+ {
[%eval -354,30] [%emt 0:00:10] (Qc3)} 51. Kf1 {[%eval -311,31] [%emt 0:00:23]}
Qd6 {[%eval -510,31] [%emt 0:00:12] (Qc3)} 52. gxh5 {[%eval -284,30] [%emt 0:
00:13]} Bg5 {[%eval -553,30] [%emt 0:00:04]} 53. Qg1 {[%eval -500,33] [%emt 0:
00:21]} Qd2 {[%eval -661,32] [%emt 0:00:11]} 54. h4 {[%eval -698,34] [%emt 0:
00:34]} Bd7 {[%eval -843,33] [%emt 0:00:17]} 55. Qf2 {[%eval -693,34] [%emt 0:
00:22]} Qxf2+ {[%eval -811,28] [%emt 0:00:04]} 56. Kxf2 {[%eval -692,5] [%emt
0:00:00]} Bxh4+ {[%eval -1109,30] [%emt 0:00:16]} 0-1
[/pgn]

thanks for the second diagram, Bram.

this is indeed a very spectacular position, worth bitmap-saving somewhere.
those are not just 4 quadruple pawns, but also 4 passers, especially the very strong f7 one.

[Lyudmil Tsvetkov]

seems my initial searches w/ K were quite lucky as i haven't been able to reproduce that result after 4-5 searches. houdini seems faster but can still take over a minute. SF consistently under 30 seconds. dont know how they do it but i sure hope someone can figure it out!

this is easy for engines, much contrary to what we counter-intuitively would think, simply because the position is relatively uncomplex, few pieces, fewer legal moves, almost all moves have to do with either a check, capture, or other forced move, which moves engines as a rule extend some plies further; even if they extend only 1 ply on each move, as the next move will be again a capture/check, they will extend again, so obviously missing nothing and doing like a full search.

you can not do better than an entity that does a full search, skipping nothing, even if its eval is a bit/very much off target.

[Guenther]

and the quadruple winning pawns position
[D] 6k1/Q4p2/2bq1p1b/7P/2P2p2/1P3p1P/8/2N1RK2 b - - 0 52


[pgn]
[Event "StockFish 8 vs Komodo 10.3, Rapid 40m+4"]
[Site "Hurnavich-PC"]
[Date "2016.12.31"]
[Round "2"]
[White "Komodo 10.3 64-bit LTC"]
[Black "StockFish 8 MP"]
[Result "0-1"]
[ECO "B96"]
[Annotator "0.05;0.20"]
[PlyCount "112"]
[EventDate "2016.??.??"]
[TimeControl "2400+4"]

{AMD Phenom(tm) II X6 1100T Processor 3625 MHz W=30.8 plies; 8,410kN/s; 6,495,
173 TBAs B=30.7 plies; 8,306kN/s; 3,707,636 TBAs} 1. e4 c5 2. Nf3 d6 3. d4 cxd4
4. Nxd4 Nf6 5. Nc3 a6 6. Bg5 Nbd7 7. f4 e6 8. Qe2 Be7 9. O-O-O Qc7 10. g4 b5
11. a3 {Both last book move} h6 {[%eval 20,29] 108} 12. Bh4 {[%eval 5,29] 82}
Bb7 {[%eval 11,29] [%emt 0:00:43]} 13. Kb1 {[%eval 19,31] 114 (f5)} Rc8 {
[%eval 0,31] [%emt 0:00:27]} 14. Bg2 {[%eval 6,31] 116} Qc4 {[%eval 0,28]
[%emt 0:00:51]} 15. Qe1 {[%eval 0,31] 121 (h3)} b4 {[%eval -32,29] [%emt 0:00:
28]} 16. axb4 {[%eval -6,29] [%emt 0:00:28]} Qxb4 {[%eval -17,28] [%emt 0:00:
18]} 17. Nb3 {[%eval 0,32] 134 (Bxf6)} Nc5 {[%eval 0,30] 125} 18. Rd4 {[%eval
-6,30] [%emt 0:00:39]} Qb6 {[%eval -13,33] [%emt 0:00:59]} 19. Nxc5 {[%eval -6,
30] [%emt 0:00:31]} Qxc5 {[%eval -12,31] [%emt 0:00:26]} 20. Rd3 {[%eval 0,29]
[%emt 0:00:37]} a5 {[%eval -18,32] 85 (Rb8)} 21. Qd2 {[%eval 0,33] 60} Ba6 {
[%eval -2,35] 338} 22. Bxf6 {[%eval 0,36] 84} gxf6 {[%eval -27,30] [%emt 0:00:
38]} 23. Rd4 {[%eval 0,33] [%emt 0:00:47] (Na4)} Rb8 {[%eval -27,30] [%emt 0:
00:44]} 24. b3 {[%eval 0,34] [%emt 0:00:51] (Nd1)} Rb4 {[%eval -36,31] [%emt 0:
00:43] (Bc8)} 25. Rxb4 {[%eval 0,34] 60} axb4 {[%eval -16,34] 83} 26. Na2 {
[%eval 0,33] [%emt 0:00:22]} O-O {[%eval -37,31] [%emt 0:00:07] (Bb7)} 27. Nxb4
{[%eval -6,35] 142} Bb5 {[%eval -44,32] [%emt 0:00:41] (Ra8)} 28. Rd1 {[%eval
-27,32] 93} Ra8 {[%eval -46,31] [%emt 0:00:11]} 29. Qd4 {[%eval -14,32] [%emt
0:00:36]} Qc7 {[%eval -57,34] [%emt 0:00:54]} 30. Nd3 {[%eval -29,33] 75} e5 {
[%eval -41,33] [%emt 0:00:18]} 31. Qb2 {[%eval -34,31] [%emt 0:00:21]} Qa7 {
[%eval -40,34] 140} 32. Nc1 {[%eval -31,32] [%emt 0:00:44]} exf4 {[%eval -35,
33] [%emt 0:00:53]} 33. Qd4 {[%eval -30,32] 70} Qa5 {[%eval -44,33] [%emt 0:00:
11]} 34. c4 {[%eval -29,32] 82} Bc6 {[%eval -50,30] [%emt 0:00:28]} 35. Kc2 {
[%eval -36,29] [%emt 0:00:20] (Rf1)} Bf8 {[%eval -33,31] 128 (Qe5)} 36. Rd3 {
[%eval -25,30] 102} Re8 {[%eval -41,32] 64} 37. Rd2 {[%eval -28,28] [%emt 0:00:
17]} Qa8 {[%eval -47,29] [%emt 0:00:24]} 38. h3 {[%eval -35,31] 74 (Re2)} Re6 {
[%eval -42,29] [%emt 0:00:48] (Re5)} 39. Re2 {[%eval -21,30] [%emt 0:00:26]}
Bg7 {[%eval -58,30] [%emt 0:00:30]} 40. Qd3 {[%eval -33,29] [%emt 0:00:23]} h5
{[%eval -60,29] [%emt 0:00:07]} 41. Kd1 {[%eval -35,30] [%emt 0:00:29]} Re7 {
[%eval -36,32] 142 (hxg4)} 42. Rd2 {[%eval -36,32] [%emt 0:00:47]} Re8 {[%eval
-54,29] [%emt 0:00:33]} 43. Re2 {[%eval -46,34] 128 (Bf3)} Qa5 {[%eval -80,30]
[%emt 0:00:37] (hxg4)} 44. Qd2 {[%eval -44,32] [%emt 0:00:57]} Qe5 {[%eval -85,
29] [%emt 0:00:38]} 45. Bf3 {[%eval -37,30] [%emt 0:00:33]} Ra8 {[%eval -68,31]
62} 46. Re1 {[%eval -57,29] [%emt 0:00:16] (Ke1)} Ra3 {[%eval -94,29] [%emt 0:
00:16]} 47. Ke2 {[%eval -58,31] [%emt 0:00:33]} Bh6 {[%eval -92,30] [%emt 0:00:
21]} 48. Qb4 {[%eval -71,30] [%emt 0:00:31] (Kf1)} d5 {[%eval -157,27] [%emt 0:
00:32] (Qd4)} 49. Qxa3 {[%eval -201,30] [%emt 0:00:41] (cxd5)} dxe4 {[%eval
-298,30] [%emt 0:00:20]} 50. Qa7 {[%eval -304,30] [%emt 0:00:33]} exf3+ {
[%eval -354,30] [%emt 0:00:10] (Qc3)} 51. Kf1 {[%eval -311,31] [%emt 0:00:23]}
Qd6 {[%eval -510,31] [%emt 0:00:12] (Qc3)} 52. gxh5 {[%eval -284,30] [%emt 0:
00:13]} Bg5 {[%eval -553,30] [%emt 0:00:04]} 53. Qg1 {[%eval -500,33] [%emt 0:
00:21]} Qd2 {[%eval -661,32] [%emt 0:00:11]} 54. h4 {[%eval -698,34] [%emt 0:
00:34]} Bd7 {[%eval -843,33] [%emt 0:00:17]} 55. Qf2 {[%eval -693,34] [%emt 0:
00:22]} Qxf2+ {[%eval -811,28] [%emt 0:00:04]} 56. Kxf2 {[%eval -692,5] [%emt
0:00:00]} Bxh4+ {[%eval -1109,30] [%emt 0:00:16]} 0-1
[/pgn]

I don't remember when I have seen last (if ever!) a quadruple pawn position from a real game.
Even more astonishing the lifespan of the quadruple pawn is already 12! plies when White resigned.
(the quadruple pawn would be diminished to a triple pawn in ply 13, but losing a rook)