Really difficult mate

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Jouni
Posts: 3278
Joined: Wed Mar 08, 2006 8:15 pm

Really difficult mate

Post by Jouni »

[d]6br/1KNp1n1r/2p2p2/P1ppRP2/1kP3pP/3PBB2/PN1P4/8 w - - 0 1

Mate in 22. Is this correct?
Jouni
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Jouni
Posts: 3278
Joined: Wed Mar 08, 2006 8:15 pm

Re: Really difficult mate

Post by Jouni »

Backward analysis with Houdini 6 x64-pext Tac:

1.Bxc5+ Kxc5 2.d4+ Kxd4 3.Nb5+ Kxe5 4.Nd3+ Kxf5 5.Nd4+ Kg6 6.Nf4+ Kg7 7.Nf5+ Kf8 8.Ng6+ Ke8 9.Kc8 gxf3 10.a6 f2 11.a7 f1Q 12.a8N Qf4 13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.Kc8 d5 16.a4 c3 17.dxc3 c5 18.a5 d4 19.a6 c4 20.a7 d3 21. a8=Q d2 22. Qa4#
+- (#22) Depth: 20/31 00:00:00 775kN
Jouni
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Spliffjiffer
Posts: 416
Joined: Thu Aug 02, 2012 7:48 pm
Location: Germany

Re: Really difficult mate

Post by Spliffjiffer »

a well known nice old problem...the solution is the given one and afaict it is correct (never found anything better) :-)...the initial and 9. Kc8 are the critical moves to find (for engines)
Wahrheiten sind Illusionen von denen wir aber vergessen haben dass sie welche sind.
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Eelco de Groot
Posts: 4561
Joined: Sun Mar 12, 2006 2:40 am
Full name:   

Re: Really difficult mate

Post by Eelco de Groot »

I'm afraid for Kaissa with 1 thread, move 13 was too difficult as well. Too many quiet moves perhaps in null window search. But with a few new modifications at least it found the right move 13 just now on my PC, after letting it simmer overnight. When it gets 13. Nxf4 finally down to -12 it can find the better move and then quickly sees it's much better.

Code: Select all

N1K1k1br/3p1n1r/2p2pN1/3p1N2/2P2q1P/8/P2P4/8 w - -

Engine: Kaissa IV (search_013, compile 091,512 MB)
by T. Romstad, M. Costalba, J. Kiiski, G. Linscott

19/38  0:02   -9.43    13.Nxf4 Ne5 14.Nc7+ Kf8 15.cxd5 cxd5 
                       16.h5 Be6 17.Nd4 Bg4 18.Kb7 Bxh5 
                       19.Ncxd5 Bf7 20.Nf5 Bxd5+ 21.Nxd5 Rh2 
                       22.d4 Ng4 23.Nb6 Rf2 24.Nd6 Ke7 
                       25.Ne4 Rxa2 26.Nd5+ (5.272.098) 2600 

20/41  0:02   -9.35    13.Nxf4 Ne5 14.Nc7+ Kf8 15.cxd5 cxd5 
                       16.h5 Be6 17.Nd4 Bg4 18.a3 Bxh5 
                       19.Ncxd5 Bf7 20.Nf5 Be6 21.Nd6 Kg7+ 
                       22.Kc7 Rh2 23.Nxe6+ dxe6 24.Nf4 Rxd2 
                       25.Nxe6+ Kg6 26.Nb5 (6.495.408) 2622 

21/41  0:03   -9.54--  13.Nxf4 Ne5 (7.979.987) 2540 

21/46  0:03   -9.54    13.Nxf4 Ne5 14.Nc7+ Kf8 15.cxd5 cxd5 
                       16.h5 Be6 17.Nd4 Bg4 18.Kb7 Bxh5 
                       19.Ncxd5 Bf7 20.Nf5 Bxd5+ 21.Nxd5 Rh2 
                       22.d4 Ng4 23.Nb6 Rf2 24.Nd6 Ke7 
                       25.Ndc8+ Kd8 26.Nd6 (8.532.078) 2540 

22/39  0:04   -9.44++  13.Nxf4 (11.563.802) 2564 

22/43  0:04   -9.63--  13.Nxf4 Ne5 (11.963.036) 2562 

22/43  0:05   -9.51    13.Nxf4 Ne5 14.Nc7+ Kf8 15.cxd5 cxd5 
                       16.h5 Be6 17.Nd4 Bg4 18.a4 Bxh5 
                       19.Ncxd5 Bf7 20.Nc3 Rh2 21.Nde2 R8h4 
                       22.d4 Nf3 23.Kxd7 Nxd4 24.Kc7 Nxe2 
                       25.Nfxe2 Rf2 (14.590.812) 2571 

23/34  0:06   -9.61--  13.Nxf4 Ne5 (15.810.799) 2566 

23/39  0:06   -9.64    13.Nxf4 Ne5 14.Nc7+ Kf8 15.cxd5 cxd5 
                       16.h5 Be6 17.Nd4 Bg4 18.Ndb5 d4 
                       19.Nxd4 Bxh5 20.Ncd5 Bf7 21.Nc3 Rh2 
                       22.Nfe2 Bh5 23.Kb7 Bg4 24.Kc7 Rf2 
                       25.Kd6 Kg7 (17.887.647) 2559 

24/33  0:08   -9.74--  13.Nxf4 Ne5 (22.619.912) 2542 

24/35  0:10   -9.84--  13.Nxf4 Ne5 (27.092.122) 2532 

24/43  0:12   -9.79    13.Nxf4 Ne5 14.Nc7+ Kf8 15.cxd5 cxd5 
                       16.h5 Be6 17.Nd4 Bg4 18.Kb7 Bxh5 
                       19.Nfxd5 Bf7 20.Ndb5 Kg7 21.a3 Rh2 
                       22.d4 Nf3 23.Nb6 Rb2 24.d5 Ne5 
                       25.Nd6 Bg6 26.Ncb5 (30.680.154) 2519 

25/34  0:14   -9.69++  13.Nxf4 (36.074.593) 2539 

25/36  0:14   -9.69    13.Nxf4 Ne5 14.Nc7+ Kf8 15.cxd5 cxd5 
                       16.h5 Be6 17.Nd4 Bg4 18.Kb7 Bxh5 
                       19.Nfxd5 Bf7 20.Ndb5 Kg7 21.a3 Rh2 
                       22.d4 Nf3 23.Nb6 Rb2 24.a4 Rd8 25.d5 Bg6 
                       26.Nd6 (36.348.510) 2539 

26/49  0:14   -9.59++  13.Nxf4 (36.781.459) 2538 

26/49  0:15   -9.78--  13.Nxf4 Ne5 (38.336.144) 2537 

26/52  0:17   -9.64++  13.Nxf4 (45.487.227) 2550 

26/52  0:18   -9.68    13.Nxf4 Ne5 14.Nc7+ Kf8 15.cxd5 cxd5 
                       16.h5 Be6 17.Nd4 Bg4 18.Kb7 Bxh5 
                       19.Nfxd5 Bf7 20.Ndb5 Kg7 21.d4 Nf3 
                       22.Kb6 Rh5 23.Ndc3 Rh2 24.a3 Rd2 
                       25.Kc5 Bg6 26.d5 (46.250.385) 2551 

27/41  0:18   -9.77--  13.Nxf4 Ne5 (47.536.892) 2552 

27/41  0:19   -9.68++  13.Nxf4 (49.068.376) 2553 

27/41  0:21   -9.87--  13.Nxf4 Ne5 (54.099.654) 2541 

27/41  0:26   -9.71++  13.Nxf4 (66.545.541) 2547 

27/41  0:28   -9.47++  13.Nxf4 (71.514.739) 2552 

27/41  0:28   -9.42    13.Nxf4 Ne5 14.Nc7+ Kf8 15.cxd5 cxd5 
                       16.h5 Be6 17.Nd4 Bg4 18.Kb7 Bxh5 
                       19.a4 Bg4 20.Ncxd5 Kf7 21.Nb5 Rh2 
                       22.Nd6+ Kg7 23.d4 Rb2+ 24.Nb5 Nc4 
                       25.Ndc3 Rc2 26.Ne4 (72.672.171) 2552 

28/33  0:29   -9.51--  13.Nxf4 Ne5 (74.468.678) 2549 

28/35  0:30   -9.42++  13.Nxf4 (76.505.044) 2547 

28/40  0:30   -9.61--  13.Nxf4 Ne5 (77.748.929) 2547 

28/40  0:37   -9.79--  13.Nxf4 Ne5 (96.305.029) 2563 

28/40  0:40   -10.03-- 13.Nxf4 Ne5 (103.211.884) 2561 

28/40  0:46   -9.82++  13.Nxf4 (119.348.464) 2577 

28/43  0:47   -9.44++  13.Nxf4 (122.622.341) 2581 

28/52  0:48   -9.97    13.Nxf4 Ne5 14.Nc7+ Kf8 15.cxd5 cxd5 
                       16.h5 Be6 17.Nd4 Bg4 18.Kb7 Bxh5 
                       19.Nfxd5 Bf7 20.Ndb5 Kg7 21.d4 Nf3 
                       22.a3 Rh4 23.Ne7 Kf8 24.Nf5 Rf4 
                       25.Nfd6 Nxd4 26.Nxf7 (125.248.757) 2583 

29/40  0:49   -9.88    13.Nxf4 Ne5 14.Nc7+ Kf8 15.cxd5 cxd5 
                       16.h5 Be6 17.Nd4 Bg4 18.Kb7 Bxh5 
                       19.Nfxd5 Bf7 20.Ndb5 Kg7 21.d4 Nf3 
                       22.a3 Rh4 23.Ne7 Kf8 24.Nf5 Rf4 
                       25.Nfd6 Nxd4 26.Nxf7 (127.345.160) 2583 

30/43  0:50   -9.78++  13.Nxf4 (131.788.695) 2586 

30/43  0:53   -9.98--  13.Nxf4 Ne5 (137.443.429) 2589 

30/43  1:00   -9.83++  13.Nxf4 (156.426.590) 2588 

30/54  1:04   -9.65++  13.Nxf4 (166.232.402) 2588 

30/54  1:06   -9.56    13.Nxf4 Ne5 14.Nc7+ Kf8 15.cxd5 cxd5 
                       16.h5 Be6 17.Nd4 Bg4 18.Ncxd5 d6+ 
                       19.Kb8 Bxh5 20.a4 Rd7 21.Nc7 Kf7+ 
                       22.Kb7 Bg4 23.Nfd5 Rh2 24.Nb6 Rd8 
                       25.Ncb5 Rxd2 26.Kc7 (172.470.472) 2587 

31/37  1:07   -9.65--  13.Nxf4 Ne5 (175.682.832) 2588 

31/37  1:13   -9.75--  13.Nxf4 Ne5 (189.582.599) 2588 

31/37  1:15   -9.88--  13.Nxf4 Ne5 (195.575.536) 2590 

31/37  1:22   -10.07-- 13.Nxf4 Ne5 (214.813.425) 2601 

31/37  1:32   -9.92++  13.Nxf4 (242.161.093) 2616 

31/37  1:33   -9.79    13.Nxf4 Ne5 14.Nc7+ Kf8 15.cxd5 cxd5 
                       16.h5 Be6 17.Nd4 Bf7 18.Ncxd5 Bxd5 
                       19.Nxd5 Rxh5 20.Nb6 Rh3 21.Nb3 Rd3 
                       22.Na4 Kg7+ 23.Kc7 d6 24.Nb2 Rf3 
                       25.Nd1 Ra8 26.Nc3 (244.389.930) 2617 

32/44  1:34   -9.88--  13.Nxf4 Ne5 (246.658.092) 2616 

32/44  1:41   -9.98--  13.Nxf4 Ne5 (265.347.789) 2610 

32/44  1:50   -10.12-- 13.Nxf4 Ne5 (287.415.367) 2612 

32/44  1:52   -10.00++ 13.Nxf4 (295.156.737) 2615 

32/44  1:54   -9.91    13.Nxf4 Ne5 14.Nc7+ Kf8 15.cxd5 cxd5 
                       16.h5 Be6 17.Nd4 Bf7 18.Kb7 Bxh5 
                       19.Nfxd5 Bf7 20.Ndb5 Kg7 21.Nb4 Rh4 
                       22.a3 Nc4 23.d4 R8h5 24.Kc8 Re4 
                       25.Kb7 Rh3 26.Ncd5 (300.031.019) 2616 

33/46  1:57   -10.01-- 13.Nxf4 Ne5 (308.792.524) 2617 

33/57  2:03   -10.01   13.Nxf4 Ne5 14.Nc7+ Kf8 15.cxd5 cxd5 
                       16.h5 Be6 17.Nd4 Bf7 18.Kb7 Bxh5 
                       19.Nfxd5 Bf7 20.Ndb5 Kg7 21.d4 Nf3 
                       22.a4 Rh4 23.Nb6 Nxd4 24.Nxd7 Nb3 
                       25.Nb6 Rd8 26.Nc3 (323.173.478) 2619 

34/39  2:23   -10.01   13.Nxf4 Ne5 14.Nc7+ Kf8 15.cxd5 cxd5 
                       16.h5 Be6 17.Nd4 Bf7 18.Kb7 Bxh5 
                       19.Nfxd5 Bf7 20.Ndb5 Kg7 21.d4 Nf3 
                       22.a4 Rh4 23.Nd6 Nxd4 24.Nxf7 Kxf7 
                       25.Nb6 Rd8 26.Ncd5 (376.642.257) 2626 

35/56  2:57   -10.11-- 13.Nxf4 Ne5 (467.418.513) 2638 

35/56  3:06   -10.20-- 13.Nxf4 Ne5 (492.422.122) 2640 

35/56  3:12   -10.11++ 13.Nxf4 (507.445.205) 2641 

35/56  3:58   -10.34-- 13.Nxf4 Ne5 (630.351.020) 2643 

35/56  4:36   -10.13++ 13.Nxf4 (733.467.033) 2649 

35/56  4:47   -10.13   13.Nxf4 Ne5 14.Nc7+ Kf8 15.cxd5 cxd5 
                       16.h5 Be6 17.Nd4 Bf7 18.Kb7 Bxh5 
                       19.Nfxd5 Bf7 20.Ndb5 Kg7 21.d4 Nf3 
                       22.Ndc3 Rh2 23.a4 R8h4 24.a5 Nxd4 
                       25.a6 Nxb5 26.N3xb5 (760.286.918) 2648 

36/58  4:52   -10.04++ 13.Nxf4 (773.721.210) 2647 

36/58  4:59   -10.23-- 13.Nxf4 Ne5 (793.372.388) 2645 

36/58  5:10   -10.09++ 13.Nxf4 (822.942.265) 2646 

36/61  5:20   -10.24   13.Nxf4 Ne5 14.Nc7+ Kf8 15.cxd5 cxd5 
                       16.h5 Be6 17.Nd4 Bf7 18.a4 Bxh5 
                       19.a5 Kg7+ 20.Kb7 Bg4 21.Ncb5 Rh2 
                       22.a6 Rxd2 23.a7 Ra2 24.Nxd5 Nc4 
                       25.Nf4 Rb2 26.Kc7 (849.691.537) 2647 

37/54  5:25   -10.14++ 13.Nxf4 (860.796.705) 2647 

37/54  5:28   -10.14   13.Nxf4 Ne5 14.Nc7+ Kf8 15.cxd5 cxd5 
                       16.h5 Be6 17.Nd4 Bf7 18.a4 Bxh5 
                       19.a5 Kg7+ 20.Kb7 Bg4 21.a6 Rh2 
                       22.a7 Rxd2 23.Ndb5 d4 24.a8Q Bf3+ 
                       25.Nfd5 Rxa8 26.Kxa8 (868.972.047) 2646 

38/48  5:29   -10.04++ 13.Nxf4 (871.792.240) 2646 

38/48  5:48   -10.24-- 13.Nxf4 Ne5 (921.478.563) 2644 

38/55  6:15   -10.09++ 13.Nxf4 (990.667.019) 2640 

38/55  6:38   -10.02   13.Nxf4 Ne5 14.Nc7+ Kf8 15.cxd5 cxd5 
                       16.h5 Be6 17.Nd4 Bf7 18.Kb7 Bxh5 
                       19.Nfxd5 Bf7 20.Ndb5 Kg7 21.a4 Nd3 
                       22.a5 Rh2 23.a6 Rxd2 24.Ne7 Bh5 
                       25.a7 Bf3+ 26.Kb6 (1.051.178.312) 2638 

39/53  6:59   -10.12-- 13.Nxf4 Ne5 (1.106.398.043) 2636 

39/53  7:24   -10.11   13.Nxf4 Ne5 14.Nc7+ Kf8 15.cxd5 cxd5 
                       16.h5 Be6 17.Nd4 Bf7 18.Kb7 Bxh5 
                       19.Nfxd5 Bf7 20.Ndb5 Kg7 21.a4 Nd3 
                       22.a5 Rh2 23.a6 Rxd2 24.Ne7 Bh5 
                       25.Nf5+ Kh7 26.Kb6 (1.173.905.360) 2638 

40/51  8:47   -10.21-- 13.Nxf4 Ne5 (1.393.557.587) 2641 

40/51  9:25   -10.30-- 13.Nxf4 Ne5 (1.492.539.558) 2639 

40/66  10:20  -10.24   13.Nxf4 Ne5 14.Nc7+ Kf8 15.cxd5 cxd5 
                       16.h5 Be6 17.Nd4 Bf7 18.Kb7 Bxh5 
                       19.a4 Bg4 20.a5 Rh2 21.a6 Rxd2 22.a7 Kg7 
                       23.Ncb5 Ra2 24.Nxd5 Nc4 25.Nf4 Rb2 
                       26.Kc7 (1.637.517.241) 2637 

41/39  12:05  -10.34-- 13.Nxf4 Ne5 (1.918.238.021) 2642 

41/43  13:08  -10.43-- 13.Nxf4 Ne5 (2.084.091.273) 2643 

41/65  14:47  -10.34++ 13.Nxf4 (2.349.084.733) 2647 

41/68  14:56  -10.24   13.Nxf4 Ne5 14.Nc7+ Kf8 15.cxd5 cxd5 
                       16.h5 Be6 17.Nd4 Bf7 18.a4 Bxh5 
                       19.Ncb5 Bg4 20.Kb7 Rh2 21.a5 Rxd2 
                       22.a6 Kg7 23.a7 Ra2 24.Nc3 Rb2+ 
                       25.Ncb5 Nc4 26.Kc7 (2.373.651.870) 2647 

42/63  15:04  -10.33-- 13.Nxf4 Ne5 (2.393.751.408) 2647 

42/63  15:59  -10.43-- 13.Nxf4 Ne5 (2.539.994.203) 2648 

42/63  17:55  -10.56-- 13.Nxf4 Ne5 (2.846.958.943) 2647 

42/63  18:14  -10.45++ 13.Nxf4 (2.898.053.545) 2648 

42/63  18:31  -10.47   13.Nxf4 Ne5 14.Nc7+ Kf8 15.cxd5 cxd5 
                       16.h5 Be6 17.Nd4 Bf7 18.a4 Bxh5 
                       19.Ncb5 Bg4 20.Kc7 Rh2 21.a5 Rxd2 
                       22.a6 Kg7 23.a7 Ra2 24.Kb6 Nc4+ 
                       25.Kb7 Ra1 26.Nd3 (2.943.088.594) 2648 

43/53  18:34  -10.37++ 13.Nxf4 (2.951.140.966) 2648 

43/73  19:18  -10.44   13.Nxf4 Ne5 14.Nc7+ Kf8 15.cxd5 cxd5 
                       16.h5 Be6 17.Nd4 Bf7 18.a4 Bxh5 
                       19.Ncb5 Bg4 20.Kb7 Rh2 21.a5 Rxd2 
                       22.a6 Kg7 23.a7 Ra2 24.Nc3 Rb2+ 
                       25.Ncb5 Nc4 26.Kc7 (3.072.551.928) 2651 

44/54  20:02  -10.38   13.Nxf4 Ne5 14.Nc7+ Kf8 15.cxd5 cxd5 
                       16.h5 Be6 17.Nd4 Bf7 18.a4 Bxh5 
                       19.Ncb5 Bg4 20.Kb7 Rh2 21.a5 Rxd2 
                       22.a6 Kg7 23.a7 Ra2 24.Nc3 Rb2+ 
                       25.Ncb5 Nc4 26.Kc7 (3.191.337.944) 2653 

45/52  24:40  -10.48-- 13.Nxf4 Ne5 (3.942.897.758) 2663 

45/52  27:05  -10.57-- 13.Nxf4 Ne5 (4.336.075.443) 2667 

45/52  28:56  -10.48++ 13.Nxf4 (4.635.876.576) 2669 

45/53  32:04  -10.71-- 13.Nxf4 Ne5 (5.142.295.322) 2672 

45/53  40:57  -10.94-- 13.Nxf4 Ne5 (6.630.791.062) 2698 

45/53  49:56  -11.24-- 13.Nxf4 Ne5 (8.127.853.864) 2712 

45/53  68:06  -11.62-- 13.Nxf4 Ne5 (11.157.725.729) 2730 

45/53  70:46  -11.30++ 13.Nxf4 (11.617.983.365) 2735 

45/53  71:09  -10.72++ 13.Nxf4 (11.680.847.193) 2735 

45/55  78:20  -12.08-- 13.Nxf4 Ne5 (12.876.460.699) 2739 

45/57  83:56  -11.80   13.Nxf4 Ne5 14.Nc7+ Kf8 15.cxd5 Bxd5 
                       16.Nfxd5 cxd5 17.Kb7 Rh5 18.Nd4 Rxh4 
                       19.Ncb5 Rh2 20.Nb3 Rf2 21.Kc7 Ke7 
                       22.Kb6 Rb8+ 23.Ka5 Ra8+ 24.Kb4 Rxa2 
                       25.N5d4 Nf3 26.Nf5+ (13.816.178.519) 2743 

46/52  88:32  -11.71++ 13.Nxf4 (14.579.648.533) 2744 

46/52  89:28  -11.75   13.Nxf4 Ne5 14.cxd5 Bxd5 15.Nb6 Be6 
                       16.Nd6+ Ke7+ 17.Kc7 Rxh4 18.Ne2 Rh2 
                       19.Nc3 Rxd2 20.Nce4 Rxa2 21.Nbc8+ Kf8 
                       22.Nxf6 Rh4 23.Nfe4 Re2 24.Nc5 Rd4 
                       25.Nb6 Bg4 26.Nb3 (14.736.640.437) 2744 

47/51  100:17 -11.85-- 13.Nxf4 Ne5 (16.575.334.358) 2754 

47/57  104:35 -11.95-- 13.Nxf4 Ne5 (17.296.342.718) 2756 

47/57  105:02 -11.85++ 13.Nxf4 (17.368.031.370) 2755 

47/57  105:17 -11.85   13.Nxf4 Ne5 14.cxd5 Bxd5 15.Nb6 Be6 
                       16.Nd6+ Ke7+ 17.Kc7 Rxh4 18.Ne2 Rh2 
                       19.Nc3 Rxd2 20.Nce4 Rxa2 21.Nbc8+ Kf8 
                       22.Nxf6 Rh4 23.Nfe4 Re2 24.Nc5 Rd4 
                       25.Nb6 Rc2 26.Nce4 (17.410.039.701) 2755 

48/58  107:32 -11.93   13.Nxf4 Ne5 14.cxd5 Bxd5 15.Nb6 Be6 
                       16.Nd6+ Ke7+ 17.Kc7 Rxh4 18.Ne2 Rh2 
                       19.Nc3 Rxd2 20.Nce4 Rxa2 21.Nbc8+ Kf8 
                       22.Nxf6 Rh4 23.Nfe4 Re2 24.Nc5 Rd4 
                       25.Nb6 Rc2 26.Nce4 (17.790.485.289) 2757 

49/69  108:17 -11.83++ 13.Nxf4 (17.915.654.036) 2757 

49/69  108:40 -11.83   13.Nxf4 Ne5 14.cxd5 Bxd5 15.Nb6 Be6 
                       16.Nd6+ Ke7+ 17.Kc7 Rxh4 18.Ne2 Rh2 
                       19.Nc3 Rxd2 20.Nce4 Rxa2 21.Nbc8+ Kf8 
                       22.Nxf6 Rh4 23.Nfe4 Re2 24.Nc5 Rd4 
                       25.Ndb7 Bg4 26.Ncd6 (17.980.169.109) 2757 

50/55  112:03 -11.93-- 13.Nxf4 Ne5 (18.552.765.213) 2759 

50/55  118:06 -12.02-- 13.Nxf4 Ne5 (19.563.079.317) 2760 

50/59  136:52 -12.16-- 13.Nxf4 Ne5 (22.710.047.826) 2765 

50/59  164:54 -12.34-- 13.Nxf4 Ne5 (27.453.703.657) 2774 

50/63  208:07 -12.19++ 13.Nc7+ (34.740.254.851) 2781 

50/63  208:36 -11.88++ 13.Nc7+ (34.822.573.822) 2782 

50/63  209:13 -11.50++ 13.Nc7+ (34.921.152.178) 2781 

50/63  209:38 -11.04++ 13.Nc7+ (34.992.158.279) 2781 

50/63  209:52 -10.49++ 13.Nc7+ (35.029.823.358) 2781 

50/63  210:17 -9.82++  13.Nc7+ (35.094.543.746) 2781 

50/63  210:42 -9.02++  13.Nc7+ (35.158.594.324) 2780 

50/63  211:08 -8.09++  13.Nc7+ (35.224.884.231) 2780 

50/63  211:26 -6.99++  13.Nc7+ (35.266.447.806) 2779 

50/63  211:50 -5.69++  13.Nc7+ (35.320.066.326) 2778 

50/63  211:56 -4.18++  13.Nc7+ (35.333.771.019) 2778 

50/63  212:01 -2.41++  13.Nc7+ (35.343.092.027) 2778 

50/63  212:03 -0.36++  13.Nc7+ (35.347.777.879) 2778 

50/63  212:04 +2.01++  13.Nc7+ (35.350.454.696) 2778 

50/63  212:05 +4.78++  13.Nc7+ (35.351.848.479) 2778 

50/63  212:05 +8.00++  13.Nc7+ (35.352.297.323) 2778 

50/63  212:05 +11.72++ 13.Nc7+ (35.352.590.658) 2778 

50/63  212:05 +16.02++ 13.Nc7+ (35.352.795.414) 2778 

50/63  212:05 +20.99++ 13.Nc7+ (35.353.029.583) 2778 

50/63  212:05 +26.73++ 13.Nc7+ (35.353.161.144) 2778 

50/63  212:05 +33.36++ 13.Nc7+ (35.353.250.456) 2778 

50/63  212:05 +41.00++ 13.Nc7+ (35.353.324.355) 2778 

50/63  212:05 +49.81++ 13.Nc7+ (35.353.350.552) 2778 

50/63  212:05 +59.97++ 13.Nc7+ (35.353.363.040) 2778 

50/63  212:05 +71.68++ 13.Nc7+ (35.353.375.944) 2778 

50/63  212:05 +M12++   13.Nc7+ (35.353.382.243) 2778 

50/63  212:05 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 c5 19.a7 cxd2 
                       20.a8N Nd8 21.Nd6+ (35.353.419.922) 2778 

51/18  212:07 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 c5 19.a7 cxd2 
                       20.a8N Nd8 21.Nd6+ (35.359.079.172) 2778 

52/18  212:08 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 c5 19.a7 cxd2 
                       20.a8N Nd8 21.Nd6+ (35.360.784.358) 2778 

53/18  212:08 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 c5 19.a7 cxd2 
                       20.a8N Nd8 21.Nd6+ (35.362.802.413) 2778 

54/18  212:09 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 c5 19.a7 cxd2 
                       20.a8N Nd8 21.Nd6+ (35.365.113.199) 2778 

55/18  212:10 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 c5 19.a7 cxd2 
                       20.a8N Nd8 21.Nd6+ (35.367.061.038) 2778 

56/18  212:11 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 c5 19.a7 cxd2 
                       20.a8N Nd8 21.Nd6+ (35.370.405.552) 2778 

57/18  212:13 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 c5 19.a7 cxd2 
                       20.a8N Nd8 21.Nd6+ (35.374.506.162) 2778 

58/18  212:14 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 c5 19.a7 cxd2 
                       20.a8N Nd8 21.Nd6+ (35.378.002.828) 2778 

59/18  212:15 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 c5 19.a7 cxd2 
                       20.a8N Nd8 21.Nd6+ (35.381.191.157) 2778 

60/18  212:17 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 c5 19.a7 cxd2 
                       20.a8N Nd8 21.Nd6+ (35.387.806.069) 2778 

61/18  212:18 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 c5 19.a7 cxd2 
                       20.a8N Nd8 21.Nd6+ (35.390.426.497) 2778 

62/18  212:20 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 c5 19.a7 cxd2 
                       20.a8N Nd8 21.Nd6+ (35.395.846.679) 2778 

63/18  212:22 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 c5 19.a7 cxd2 
                       20.a8N Nd8 21.Nd6+ (35.400.218.752) 2778 

64/18  212:24 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 c5 19.a7 cxd2 
                       20.a8N Nd8 21.Nd6+ (35.409.008.280) 2778 

65/18  212:26 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 c5 19.a7 cxd2 
                       20.a8N Nd8 21.Nd6+ (35.414.233.987) 2778 

66/18  212:29 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 c5 19.a7 cxd2 
                       20.a8N Nd8 21.Nd6+ (35.421.044.819) 2778 

67/18  212:31 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 c5 19.a7 cxd2 
                       20.a8N Nd8 21.Nd6+ (35.428.538.086) 2778 

68/18  212:35 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 cxd2 19.a7 d3 
                       20.a8N Nd8 21.Nd6+ (35.441.288.631) 2778 

69/18  212:39 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 cxd2 19.a7 d3 
                       20.a8N Nd8 21.Nd6+ (35.451.834.765) 2778 

70/18  212:46 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 cxd2 19.a7 d1Q 
                       20.a8N Qf3 21.Nc7+ (35.470.457.693) 2778 

71/18  212:49 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 cxd2 19.a7 d1Q 
                       20.a8N Qf3 21.Nc7+ (35.480.345.798) 2778 

72/18  212:53 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 cxd2 19.a7 d1Q 
                       20.a8N Qf3 21.Nc7+ (35.492.042.233) 2778 

73/18  212:57 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 cxd2 19.a7 d1Q 
                       20.a8N Qf3 21.Nc7+ (35.504.213.745) 2778 

74/18  213:03 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 cxd2 19.a7 d1Q 
                       20.a8N Qf3 21.Nc7+ (35.522.020.354) 2778 

75/18  213:12 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 cxd2 19.a7 d1Q 
                       20.a8N Qf3 21.Nc7+ (35.550.144.444) 2778 

76/18  213:18 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 cxd2 19.a7 d1Q 
                       20.a8N Qf3 21.Nc7+ (35.570.361.160) 2779 

77/18  213:30 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 cxd2 19.a7 d1Q 
                       20.a8N Qf3 21.Nc7+ (35.606.784.387) 2779 

78/18  213:38 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 cxd2 19.a7 d1Q 
                       20.a8N Qf3 21.Nc7+ (35.631.263.183) 2779 

79/18  213:46 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 cxd2 19.a7 d1Q 
                       20.a8N Qf3 21.Nc7+ (35.656.754.036) 2779 

80/18  214:04 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 cxd2 19.a7 d1Q 
                       20.a8N Qf3 21.Nc7+ (35.711.981.450) 2780 

81/18  214:22 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 cxd2 19.a7 d1Q 
                       20.a8N Qf3 21.Nc7+ (35.767.637.517) 2780 

82/18  214:47 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 cxd2 19.a7 d1Q 
                       20.a8N Qf3 21.Nc7+ (35.844.410.230) 2781 

83/18  215:00 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 cxd2 19.a7 d1Q 
                       20.a8N Qf3 21.Nc7+ (35.885.948.849) 2781 

84/18  215:30 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 cxd2 19.a7 d1Q 
                       20.a8N Qf3 21.Nc7+ (35.980.937.146) 2782 

85/18  215:42 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 cxd2 19.a7 d1Q 
                       20.a8N Qf3 21.Nc7+ (36.017.760.250) 2783 

86/18  215:58 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 cxd2 19.a7 d1Q 
                       20.a8N Qf3 21.Nc7+ (36.071.077.402) 2783 

87/18  216:42 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 cxd2 19.a7 d1Q 
                       20.a8N Qf3 21.Nc7+ (36.209.028.588) 2784 

88/18  217:00 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 cxd2 19.a7 d1Q 
                       20.a8N Qf3 21.Nc7+ (36.267.635.690) 2785 

89/18  217:56 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 cxd2 19.a7 d1Q 
                       20.a8N Qf3 21.Nc7+ (36.444.297.004) 2786 

90/18  219:09 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 cxd2 19.a7 d1Q 
                       20.a8N Qf3 21.Nc7+ (36.691.457.971) 2790 

91/18  220:09 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 cxd2 19.a7 d1Q 
                       20.a8N Qf3 21.Nc7+ (36.885.646.769) 2792 

92/18  221:20 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 cxd2 19.a7 d1Q 
                       20.a8N Qf3 21.Nc7+ (37.115.254.363) 2794 

93/18  221:45 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 cxd2 19.a7 d1Q 
                       20.a8N Qf3 21.Nc7+ (37.200.642.076) 2795 

94/18  222:57 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 cxd2 19.a7 d1Q 
                       20.a8N Qf3 21.Nc7+ (37.429.487.929) 2797 

95/18  224:13 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 cxd2 19.a7 d1Q 
                       20.a8N Qf3 21.Nc7+ (37.671.896.760) 2800 

96/18  225:43 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 cxd2 19.a7 d1Q 
                       20.a8N Qf3 21.Nc7+ (37.961.160.473) 2802 

97/18  227:13 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 cxd2 19.a7 d1Q 
                       20.a8N Qf3 21.Nc7+ (38.246.150.159) 2805 

98/18  227:41 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 cxd2 19.a7 d1Q 
                       20.a8N Qf3 21.Nc7+ (38.344.752.829) 2806 

99/18  228:13 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 cxd2 19.a7 d1Q 
                       20.a8N Qf3 21.Nc7+ (38.454.792.669) 2808 

100/18 230:45 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 cxd2 19.a7 d1Q 
                       20.a8N Qf3 21.Nc7+ (38.959.046.045) 2813 

101/18 231:35 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 cxd2 19.a7 d1Q 
                       20.a8N Qf3 21.Nc7+ (39.128.210.981) 2815 

102/18 232:19 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 cxd2 19.a7 d1Q 
                       20.a8N Qf3 21.Nc7+ (39.284.801.226) 2818 

103/18 235:32 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 cxd2 19.a7 d1Q 
                       20.a8N Qf3 21.Nc7+ (39.890.850.622) 2822 

104/18 239:17 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 cxd2 19.a7 d1Q 
                       20.a8N Qf3 21.Nc7+ (40.599.548.959) 2827 

105/18 244:14 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 cxd2 19.a7 d1Q 
                       20.a8N Qf3 21.Nc7+ (41.536.352.692) 2834 

106/18 245:06 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 cxd2 19.a7 d1Q 
                       20.a8N Qf3 21.Nc7+ (41.718.505.278) 2836 

107/18 246:15 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 cxd2 19.a7 d1Q 
                       20.a8N Qf3 21.Nc7+ (41.958.723.243) 2839 

108/18 247:22 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 cxd2 19.a7 d1Q 
                       20.a8N Qf3 21.Nc7+ (42.193.410.371) 2842 

109/18 248:50 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 cxd2 19.a7 d1Q 
                       20.a8N Qf3 21.Nc7+ (42.493.996.480) 2846 

110/18 251:00 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 cxd2 19.a7 d1Q 
                       20.a8N Qf3 21.Nc7+ (42.930.464.510) 2850 

111/18 339:10 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 cxd2 19.a7 d1Q 
                       20.a8N Qf3 21.Nc7+ (62.430.040.515) 3067 

112/18 341:03 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 cxd2 19.a7 d1Q 
                       20.a8N Qf3 21.Nc7+ (62.862.187.850) 3071 

113/18 344:23 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 cxd2 19.a7 d1Q 
                       20.a8N Qf3 21.Nc7+ (63.548.784.106) 3075 

114/18 348:47 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 cxd2 19.a7 d1Q 
                       20.a8N Qf3 21.Nc7+ (64.467.508.944) 3080 

115/18 441:47 +M9      13.Nc7+ Qxc7+ 14.Kxc7 dxc4 15.a4 d5 
                       16.Kc8 d4 17.a5 c3 18.a6 cxd2 19.a7 d1Q 
                       20.a8N Qf3 21.Nc7+ (81.929.675.962) 3090

If I give Kaissa 13 Nc7+ as a given and let it search from there, empty hash, somehow it finds Mate 9 in 1 second...

Code: Select all

search_008 086


2K1k1br/2Np1n1r/2p2pN1/3p1N2/2P2q1P/8/P2P4/8 b - -

Engine: Kaissa IV (512 MB)
by T. Romstad, M. Costalba, J. Kiiski, G.

37/19  0:01   +M9      13...Qxc7+ 14.Kxc7 d6 15.Kc8 dxc4 
                       16.a4 c5 17.a5 c3 18.dxc3 d5 19.a6 d4 
                       20.a7 dxc3 21.a8Q c2 22.Qa4+ (3.930.347) 2699 

38/19  0:01   +M9      13...Qxc7+ 14.Kxc7 d6 15.Kc8 dxc4 
                       16.a4 c5 17.a5 c3 18.dxc3 d5 19.a6 d4 
                       20.a7 dxc3 21.a8Q c2 22.Qa4+ (4.049.386) 2685 

39/19  0:01   +M9      13...Qxc7+ 14.Kxc7 d6 15.Kc8 dxc4 
                       16.a4 c5 17.a5 c3 18.dxc3 d5 19.a6 d4 
                       20.a7 dxc3 21.a8Q c2 22.Qa4+ (4.192.174) 2671 

40/19  0:01   +M9      13...Qxc7+ 14.Kxc7 d6 15.Kc8 dxc4 
                       16.a4 c5 17.a5 c3 18.dxc3 d5 19.a6 d4 
                       20.a7 dxc3 21.a8Q c2 22.Qa4+ (4.466.516) 2653 

41/19  0:01   +M9      13...Qxc7+ 14.Kxc7 d6 15.Kc8 dxc4 
                       16.a4 c5 17.a5 c3 18.dxc3 d5 19.a6 d4 
                       20.a7 dxc3 21.a8Q c2 22.Qa4+ (4.726.549) 2650 

42/19  0:01   +M9      13...Qxc7+ 14.Kxc7 d6 15.Kc8 dxc4 
                       16.a4 c5 17.a5 c3 18.dxc3 d5 19.a6 d4 
                       20.a7 dxc3 21.a8Q c2 22.Qa4+ (4.995.958) 2656 

43/19  0:01   +M9      13...Qxc7+ 14.Kxc7 d6 15.Kc8 dxc4 
                       16.a4 c5 17.a5 c3 18.dxc3 d5 19.a6 d4 
                       20.a7 dxc3 21.a8Q c2 22.Qa4+ (5.291.182) 2660 

44/19  0:02   +M9      13...Qxc7+ 14.Kxc7 d6 15.Kc8 dxc4 
                       16.a4 c5 17.a5 c3 18.dxc3 d5 19.a6 d4 
                       20.a7 dxc3 21.a8Q c2 22.Qa4+ (5.601.621) 2666 

45/19  0:02   +M9      13...Qxc7+ 14.Kxc7 d6 15.Kc8 dxc4 
                       16.a4 c5 17.a5 c3 18.dxc3 d5 19.a6 d4 
                       20.a7 dxc3 21.a8Q c2 22.Qa4+ (5.936.875) 2665 

46/19  0:02   +M9      13...Qxc7+ 14.Kxc7 d6 15.Kc8 dxc4 
                       16.a4 c5 17.a5 c3 18.dxc3 d5 19.a6 d4 
                       20.a7 dxc3 21.a8Q c2 22.Qa4+ (6.261.588) 2663 

47/19  0:02   +M9      13...Qxc7+ 14.Kxc7 d6 15.Kc8 dxc4 
                       16.a4 c5 17.a5 c3 18.dxc3 d5 19.a6 d4 
                       20.a7 dxc3 21.a8Q c2 22.Qa4+ (6.757.320) 2674 

48/19  0:02   +M9      13...Qxc7+ 14.Kxc7 d6 15.Kc8 dxc4 
                       16.a4 c5 17.a5 c3 18.dxc3 d5 19.a6 d4 
                       20.a7 dxc3 21.a8Q c2 22.Qa4+ (7.248.137) 2670 

49/19  0:02   +M9      13...Qxc7+ 14.Kxc7 d6 15.Kc8 dxc4 
                       16.a4 c5 17.a5 c3 18.dxc3 d5 19.a6 d4 
                       20.a7 dxc3 21.a8Q c2 22.Qa4+ (7.755.262) 2675 

50/19  0:03   +M9      13...Qxc7+ 14.Kxc7 d6 15.Kc8 dxc4 
                       16.a4 c5 17.a5 c3 18.dxc3 d5 19.a6 d4 
                       20.a7 dxc3 21.a8Q c2 22.Qa4+ (8.501.254) 2679 

51/19  0:03   +M9      13...Qxc7+ 14.Kxc7 d6 15.Kc8 dxc4 
                       16.a4 c5 17.a5 c3 18.dxc3 d5 19.a6 d4 
                       20.a7 dxc3 21.a8Q c2 22.Qa4+ (8.935.600) 2680 

52/19  0:03   +M9      13...Qxc7+ 14.Kxc7 d6 15.Kc8 dxc4 
                       16.a4 c5 17.a5 c3 18.dxc3 d5 19.a6 d4 
                       20.a7 dxc3 21.a8Q c2 22.Qa4+ (10.057.825) 2697 

53/19  0:03   +M9      13...Qxc7+ 14.Kxc7 d6 15.Kc8 dxc4 
                       16.a4 c5 17.a5 c3 18.dxc3 d5 19.a6 d4 
                       20.a7 dxc3 21.a8Q c2 22.Qa4+ (10.671.849) 2703 

54/19  0:04   +M9      13...Qxc7+ 14.Kxc7 d6 15.Kc8 dxc4 
                       16.a4 c5 17.a5 c3 18.dxc3 d5 19.a6 d4 
                       20.a7 dxc3 21.a8Q c2 22.Qa4+ (11.663.155) 2712 

55/19  0:04   +M9      13...Qxc7+ 14.Kxc7 d6 15.Kc8 dxc4 
                       16.a4 c5 17.a5 c3 18.dxc3 d5 19.a6 d4 
                       20.a7 dxc3 21.a8Q c2 22.Qa4+ (12.763.871) 2721 

56/19  0:04   +M9      13...Qxc7+ 14.Kxc7 d6 15.Kc8 dxc4 
                       16.a4 c5 17.a5 c3 18.dxc3 d5 19.a6 d4 
                       20.a7 dxc3 21.a8Q c2 22.Qa4+ (13.357.972) 2733 

57/19  0:05   +M9      13...Qxc7+ 14.Kxc7 d6 15.Kc8 dxc4 
                       16.a4 c5 17.a5 c3 18.dxc3 d5 19.a6 d4 
                       20.a7 dxc3 21.a8Q c2 22.Qa4+ (14.599.791) 2750 

58/19  0:05   +M9      13...Qxc7+ 14.Kxc7 d6 15.Kc8 dxc4 
                       16.a4 c5 17.a5 c3 18.dxc3 d5 19.a6 d4 
                       20.a7 dxc3 21.a8Q c2 22.Qa4+ (16.118.337) 2764 

59/19  0:06   +M9      13...Qxc7+ 14.Kxc7 d6 15.Kc8 dxc4 
                       16.a4 c5 17.a5 c3 18.dxc3 d5 19.a6 d4 
                       20.a7 dxc3 21.a8Q c2 22.Qa4+ (17.838.065) 2784 

60/19  0:06   +M9      13...Qxc7+ 14.Kxc7 d6 15.Kc8 dxc4 
                       16.a4 c5 17.a5 c3 18.dxc3 d5 19.a6 d4 
                       20.a7 dxc3 21.a8Q c2 22.Qa4+ (18.819.422) 2793 

61/19  0:07   +M9      13...Qxc7+ 14.Kxc7 d6 15.Kc8 dxc4 
                       16.a4 c5 17.a5 c3 18.dxc3 d5 19.a6 d4 
                       20.a7 dxc3 21.a8Q c2 22.Qa4+ (20.150.167) 2807 

62/19  0:08   +M9      13...Qxc7+ 14.Kxc7 d6 15.Kc8 dxc4 
                       16.a4 c5 17.a5 c3 18.dxc3 d5 19.a6 d4 
                       20.a7 dxc3 21.a8Q c2 22.Qa4+ (22.655.205) 2808 

63/19  0:08   +M9      13...Qxc7+ 14.Kxc7 d6 15.Kc8 dxc4 
                       16.a4 c5 17.a5 c3 18.dxc3 d5 19.a6 d4 
                       20.a7 dxc3 21.a8Q c2 22.Qa4+ (24.587.680) 2818 

64/19  0:09   +M9      13...Qxc7+ 14.Kxc7 d6 15.Kc8 dxc4 
                       16.a4 c5 17.a5 c3 18.dxc3 d5 19.a6 d4 
                       20.a7 dxc3 21.a8Q c2 22.Qa4+ (26.833.366) 2829 

65/19  0:10   +M9      13...Qxc7+ 14.Kxc7 d6 15.Kc8 dxc4 
                       16.a4 c5 17.a5 c3 18.dxc3 d5 19.a6 d4 
                       20.a7 dxc3 21.a8Q c2 22.Qa4+ (29.042.797) 2824 

66/19  0:11   +M9      13...Qxc7+ 14.Kxc7 d6 15.Kc8 dxc4 
                       16.a4 c5 17.a5 c3 18.dxc3 d5 19.a6 d4 
                       20.a7 dxc3 21.a8Q c2 22.Qa4+ (31.994.932) 2815 

67/19  0:12   +M9      13...Qxc7+ 14.Kxc7 d6 15.Kc8 dxc4 
                       16.a4 c5 17.a5 c3 18.dxc3 d5 19.a6 d4 
                       20.a7 dxc3 21.a8Q c2 22.Qa4+ (34.681.920) 2827 

68/19  0:13   +M9      13...Qxc7+ 14.Kxc7 d6 15.Kc8 dxc4 
                       16.a4 c5 17.a5 c3 18.dxc3 d5 19.a6 d4 
                       20.a7 dxc3 21.a8Q c2 22.Qa4+ (39.003.987) 2840 

69/19  0:15   +M9      13...Qxc7+ 14.Kxc7 d6 15.Kc8 dxc4 
                       16.a4 c5 17.a5 c3 18.dxc3 d5 19.a6 d4 
                       20.a7 dxc3 21.a8Q c2 22.Qa4+ (43.677.451) 2861 

70/19  0:16   +M9      13...Qxc7+ 14.Kxc7 d6 15.Kc8 dxc4 
                       16.a4 c5 17.a5 c3 18.dxc3 d5 19.a6 d4 
                       20.a7 dxc3 21.a8Q c2 22.Qa4+ (46.698.820) 2886 

71/19  0:16   +M9      13...Qxc7+ 14.Kxc7 d6 15.Kc8 dxc4 
                       16.a4 c5 17.a5 c3 18.dxc3 d5 19.a6 d4 
                       20.a7 dxc3 21.a8Q c2 22.Qa4+ (46.819.069) 2887 

best move: Qf4xc7 time: 0:16.266 min  n/s: 2.887.214  nodes: 46.819.069
Debugging is twice as hard as writing the code in the first
place. Therefore, if you write the code as cleverly as possible, you
are, by definition, not smart enough to debug it.
-- Brian W. Kernighan
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lech
Posts: 1136
Joined: Sun Feb 14, 2010 10:02 pm

Re: Really difficult mate

Post by lech »

A try with machine tricks including:

[d]6br/1KNp1n1r/2p2p2/P1ppRP2/1kP3pP/3PBB2/PN1P4/8 w - - 0 1

Sting xx; Hash = 1024M; threads = 1

info depth 26
info currmove e5e8 currmovenumber 1
info depth 26 multipv 1 score cp -64 lowerbound nodes 951326545 nps 581098 time 1637118 pv e5e8
info currmove e5e8 currmovenumber 1
info depth 26 multipv 1 score cp -52 lowerbound nodes 963441718 nps 581248 time 1657539 pv e5e8
info currmove e5e8 currmovenumber 1
---
info currmove e3c5 currmovenumber 38
info depth 26 multipv 1 score cp -34 lowerbound nodes 1124047536 nps 579722 time 1938940 pv e3c5
info currmove e3c5 currmovenumber 1
info depth 26 multipv 1 score cp -7 lowerbound nodes 1124891538 nps 579724 time 1940391 pv e3c5
info currmove e3c5 currmovenumber 1
---
info currmove e5d5 currmovenumber 39
info depth 26 multipv 1 score cp 0 nodes 1163175824 nps 579684 time 2006566 pv e3c5 b4c5 d3d4 c5d4 e5d5 c6d5 c7b5 d4c5 d2d4 c5b4 b7a6 g4f3 b2d3 b4c4 d3b2 c4b4 b2d3 b4a4 d3c5 a4b4 c5d3
info depth 27
info currmove e3c5 currmovenumber 1
info depth 27 multipv 1 score cp 12 lowerbound nodes 1167679687 nps 579653 time 2014444 pv e3c5
info currmove e3c5 currmovenumber 1
info depth 27 multipv 1 score cp 24 lowerbound nodes 1168782515 nps 579657 time 2016332 pv e3c5
---
info currmove e3c5 currmovenumber 1
info depth 27 multipv 1 score cp 6989 lowerbound nodes 1225599017 nps 579342 time 2115501 pv e3c5
info currmove e3c5 currmovenumber 1
info depth 27 multipv 1 score cp 10487 lowerbound nodes 1225602101 nps 579339 time 2115516 pv e3c5
info depth 27 multipv 1 score cp 10487 nodes 1225602101 nps 579339 time 2115516 pv e3c5

[stop and start without clearing of HASH to get PV line quickly]

info depth 13 multipv 1 score mate 27 lowerbound nodes 482941 nps 461702 time 1046 pv e3c5
info depth 13 multipv 1 score mate 27 lowerbound nodes 482941 nps 455175 time 1061 pv e3c5
info depth 14 multipv 1 score mate 27 nodes 8566398 nps 688119 time 12449 pv e3c5 b4c5 d3d4 c5d4 c7b5 d4e5 b2d3 e5f5 b5d4 f5g6 d3f4 g6g7 d4f5 g7f8
Maybe, I can't be friendly, but let me be useful.
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Paloma
Posts: 1167
Joined: Thu Dec 25, 2008 9:07 pm
Full name: Herbert L

Re: Really difficult mate

Post by Paloma »

Spliffjiffer wrote: ↑Sat Feb 16, 2019 7:24 pm a well known nice old problem...the solution is the given one and afaict it is correct (never found anything better) :-)...the initial and 9. Kc8 are the critical moves to find (for engines)
Van Essen=M and Brillant No 65 :)
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lech
Posts: 1136
Joined: Sun Feb 14, 2010 10:02 pm

Re: Really difficult mate

Post by lech »

I think that Sting xx with machine tricks can be the TOP ELO engine. I try many positions and the result is very interesting. The alpha-beta with "machine tricks" can be much better than NN algorithms.
Maybe, I can't be friendly, but let me be useful.
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Spliffjiffer
Posts: 416
Joined: Thu Aug 02, 2012 7:48 pm
Location: Germany

Re: Really difficult mate

Post by Spliffjiffer »

yes, to trick machines with lets say multi PV first and let them now think in single PV or give them inside with multiple variation before and let them run again (oc with the filled hashes) is known to myself...the point was (until now at least) that not nearly every position can be handled like this at all...many difficult tactical positions can be solved this way extraordinary fast with special variations of AB-engines (Sting, SF(not manipulated as well), McCain, Houdini, Komodo + special settings=very, very interesting results, critter, spark/bright and many interesting approaches as well/exceptionally from time to time)...the point in the end is: there are many positions, but not nearly all positions, that are better get handled that way (exceptionally faster solved) but the remaing ones that dont get handled better this way, but exeptionally get better handled by letting the engine run as it comes ( no mullti PV, no back-forward -anylysis, and, and, and)...is the way that the user has to determine and he does it with his own risk (let the engine run for hours and see what its PV is or do the multi PV verifcation)...all in all: the most efficient way i found for myself is to begin with multi-PV (say) 35, reduce it subsequently to 2-3 variation ( lets say 35 to 30 to 20 to 15 to 10 to 7 to 5 to 4 to 3 to 2, always let the engine spend 5 mins (say) on the position with every reduction (never clear hash oc)...dont let the engine run in single PV-mode, that makes no sense to my own experience...abbort with multi-PV=2=thats the best result u can get)...its a user problem...not all positions get cracked like this...most of them u get cracked by this method but not at least all of them get cracked this way...it stays a user issue in terms of investigation and his tenacity by using the engines...what all these efforts give us is an INDICATION and not a result !...to have a pefect analysis these days is to dig, dig, dig...and dig deeper one more, more times, chess is increadably deep to find the truth even with these extremely powerful helpers. u dig and keep on digging, and at some point u get the answer ure were searching for but guy, i tell u, dont be sure about u found out, it stays an indiaction, very well, very deep, very accurate, very delightful,...but the truth u didnt found ;-)...chess is a jungle u never get the full insight in !
Wahrheiten sind Illusionen von denen wir aber vergessen haben dass sie welche sind.
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Raphexon
Posts: 476
Joined: Sun Mar 17, 2019 12:00 pm
Full name: Henk Drost

Re: Really difficult mate

Post by Raphexon »

Sting SF 18 finds: "Bxc5+ Kxc5 d4+ Kxd4 Nb5+ Kxe5 Nd3+ Kxf5 Nd4+ Kg6 Nf4+ Kg7 Nf5+ Kf8 Ng6+ Ke8 Kc8 gxf3 a6 f2 a7 f1=Q a8=N Qf4 Nc7+ Qxc7+ Kxc7 d6" after 2.6B nodes on 3 threads.

Not the mate, but finding the mate gets trivial after d6.
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Ajedrecista
Posts: 1966
Joined: Wed Jul 13, 2011 9:04 pm
Location: Madrid, Spain.

Re: Really difficult mate.

Post by Ajedrecista »

Hello:
Paloma wrote: ↑Wed Feb 20, 2019 2:50 pm
Spliffjiffer wrote: ↑Sat Feb 16, 2019 7:24 pm a well known nice old problem...the solution is the given one and afaict it is correct (never found anything better) :-)...the initial and 9. Kc8 are the critical moves to find (for engines)
Van Essen=M and Brillant No 65 :)
https://www.yacpdb.org/#275467
YACPDB wrote:Van Essen, Martin
Humor Tourney EBUR 2004
2nd Prize
[pgn][FEN "6br/1KNp1n1r/2p2p2/P1ppRP2/1kP3pP/3PBB2/PN1P4/8 w - - 0 1"] 1. Bxc5+ (1. Re8 $2 Nd6+ 2. Kb6 d4 3. Rb8 dxe3 4. a6 Bxc4 $1 5. a3+ Kxa3 6. a7 gxf3 7. Nxc4+ Nxc4+ 8. dxc4 Rxb8+ 9. axb8=Q f2 10. Nb5+ cxb5 11. Qf4 exd2 12. Qe3+ Ka4 $1 13. Qd3 Rxh4) 1... Kxc5 (1... Kxa5 2. a3 $1) 2. d4+ Kxd4 (2... Kb4 3. Re3 $1 dxc4 4. a3+ Kxa5 5. Nxc4+ Ka4 6. Bd1#) (2... Kd6 3. c5#) 3. Nb5+ $1 Kxe5 (3... cxb5 4. Rxd5#) (3... Kc5 4. d4+ Kb4 5. Re3 $1 dxc4 (5... cxb5 6. Rb3+ Kxa5 7. Rxb5#) (5... Rxh4 6. Rb3+ Kxa5 7. Ra3+ Kb4 8. Ra4#) 6. Kb6 $1 cxb5 7. a3#) 4. Nd3+ Kxf5 5. Nd4+ Kg6 6. Nf4+ Kg7 7. Nf5+ Kf8 8. Ng6+ Ke8 9. Kc8 $1 (9. a6 $2 Ne5 10. Nd6+ Kd8 11. a7 Nxg6 12. a8=Q+ Ke7 13. Nf5+ Kf7 14. Bxg4 Nxh4 ) 9... gxf3 10. a6 f2 11. a7 f1=Q 12. a8=N $1 (12. a8=Q $2 Qxf5 13. Kc7+ Nd8) 12... Qf4 $1 13. Nc7+ $1 Qxc7+ 14. Kxc7 dxc4 15. a4 d5 16. Kc8 $1 d4 17. a5 c3 18. a6 cxd2 (18... c2 19. a7 c1=Q 20. a8=N $1) 19. a7 d1=Q 20. a8=N $1 Ne5 21. Nd6# 1-0[/pgn]

It has a solution with checkmate in 21, but it is wrong after 16.- Kc8: 16.- ..., d4 is chosen at YACPDB and it is a checkmate in 5 (total: checkmate in 21); but 16.- ..., c3 is a checkmate in 6 (total: checkmate in 22).

Regards from Spain.

Ajedrecista.
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