do top programs find 35.Nb4 right away ...

[pilgrimdan]

1.Nf3 Nf6 2.c4 g6 3.g3 Bg7 4.Bg2 O-O 5.O-O d6 6.d4 Nbd7 7.Nc3 e5 8.h3
exd4 9.Nxd4 Nb6 10.Qd3 Nfd7 11.b3 Nc5 12.Qd2 a5 13.Ba3 a4 14.Rfb1 Re8
15.e3 Bd7 16.Qb2 Qg5 17.Qd2 c6 18.Nf3 Qe7 19.Nd4 Ra6 20.Qd1 f5 21.Rc1
axb3 22.axb3 Rea8 23.Bb4 Rxa1 24.Rxa1 Rxa1 25.Qxa1 f4 26.gxf4 Nd3 27.Qa7
Nc8 28.Qxb7 Nxb4 29.Qxb4 c5 30.Qa5 cxd4 31.Nd5 Qh4 32.Qa8 Kf7 33.Qb7 Ke8
34.Kf1 d3

[d]2n1k3/1Q1b2bp/3p2p1/3N4/2P2P1q/1P1pP2P/5PB1/5K2 w - - 0 35

35.Nb4 (not Ke1 not Nc7+)

35. ...Qh5 36.Qe4+ Kf8 37.Qxd3 Bxh3 38.Nd5 Kf7 39.b4 Ne7
40.Nc7 Qf5 41.Qxf5+ Bxf5 42.b5 Nc8 43.Na8 Bd3+ 44.Kg1 Bxc4 45.b6 Nxb6
46.Nxb6 Bd3 47.Bd5+ Ke7 48.f3 Be2 49.Kg2 Bd1 50.Be4 Kf6 51.Bd5 Bc2
52.Bg8 Bf8 53.e4 Kg7 54.Be6 h5 55.f5 gxf5 56.Bxf5 Kf7 57.Nd5 Bh6 58.Kg3
Bd2 59.Kh4 Bd1 60.f4 Be1+ 61.Kg5 Ba5 62.Bg6+ Kg7 63.f5 Bd2+ 64.Kh4 Kh6
65.Kg3 Bc2 66.Nf6 Bc3 67.Nxh5 Bxe4 68.Kg4 Bc2 69.Nf4 Bd1+ 70.Kh3 Bb3
71.Kg4 Be5 72.Kf3 Kg5 73.Nh3+ Kf6 74.Nf2 Kg7 75.Bh5 Kf8 76.Ng4 Bb2
77.Ke2 Ba2 78.Kd2 Ba1 79.Ne3 d5 80.Bf3 d4 81.Nd5 Bb1 82.f6 Bb2 83.Bh5
Bf5 84.Ne7 Be4 85.Bg6 Bc3+ 86.Kc1 Bb7 87.Kc2 Be1 88.Kd3 Bh4 89.Nf5 Bxf6
90.Nxd4 Ke7 draw 1/2 - 1/2

[jdart]

Houdini 6 selects 35. Nb4 instantly and sticks with it.

--Jon

[pilgrimdan]

thanks Jon … guess I need to get Houdini …

[peter]

… guess I need to get Houdini …

Or a current Fish and some advanced hardware?


2n1k3/1Q1b2bp/3p2p1/3N4/2P2P1q/1P1pP2P/5PB1/5K2 w - - 0 1

Analysis by Cfish 230219 64 POP N:

Code: Select all

35.Qb4 Kf8 36.Qd2 Bxh3 37.Qxd3 Bxg2+ 38.Kxg2 Kf7 
  -+  (-3.04)   Depth: 7/7   00:00:21  11kN
35.Nc7+ Kd8 36.Nb5 Qh5 37.Qc7+ Ke8 38.Bc6 Qxh3+ 39.Ke1 Bxc6 40.Qxc6+ Ke7 41.Qd5 
  -+  (-2.58)   Depth: 8/11   00:00:21  40kN
35.Nc7+ Kf8 36.Qd5 Qd8 37.Ne6+ Bxe6 38.Qxe6 Ne7 39.Bd5 Nxd5 40.Qxd5 
  -+  (-2.32)   Depth: 9/14   00:00:21  65kN
35.Nb4 Qh5 36.Qe4+ Kf8 37.Qxd3 Bxh3 38.Bxh3 Qxh3+ 39.Ke1 
  -+  (-2.27)   Depth: 10/18   00:00:21  127kN
35.Nc7+ Kd8 36.Nb5 Qh5 37.Qc7+ Ke8 38.Bc6 Qxh3+ 39.Ke1 Bxc6 40.Qxc6+ Kf8 
  -+  (-2.04)   Depth: 11/18   00:00:21  190kN
35.Nb4 Qh5 36.Qe4+ Kf8 37.Qxd3 Bxh3 38.e4 Bxg2+ 39.Kxg2 Kf7 40.Kg3 Qc5 41.Qd5+ Qxd5 42.cxd5 Bc3 
  -+  (-2.15)   Depth: 12/25   00:00:21  358kN
35.Nc7+ Kd8 36.Nb5 Qh5 37.Qc7+ Ke8 38.Bc6 Qxh3+ 39.Ke1 Bxc6 40.Qxc6+ Kf8 41.Kd2 Ne7 42.Qa8+ Qc8 43.Qxc8+ Nxc8 44.Kxd3 
  -+  (-1.68)   Depth: 13/25   00:00:21  624kN
35.Nc7+ Kd8 36.Nb5 Qh5 37.Bc6 Qxh3+ 38.Ke1 Bxc6 39.Qxc6 Ke7 40.Kd2 Qf5 41.Nc7 Kd8 42.Nd5 Qd7 43.Qa4 Qxa4 44.bxa4 Ne7 45.Kxd3 Nc6 46.Ke4 
  -+  (-1.84)   Depth: 14/28   00:00:21  856kN
35.Nb4 Qh5 36.Qe4+ Kf8 37.Qxd3 Bxh3 38.e4 Bxg2+ 39.Kxg2 Ke8 40.Qf3 Kd7 41.Nd3 Bd4 42.Qxh5 gxh5 43.b4 Ne7 44.Kg3 
  -+  (-1.95)   Depth: 15/30   00:00:21  1789kN
...
35.Nb4 Qh5 36.Qe4+ Ne7 37.Qxd3 Qc5 38.Qd2 Qa5 39.Qxd6 Qa1+ 40.Ke2 Qb2+ 41.Kf1 Qb1+ 42.Ke2 Qxb3 43.Bd5 Nc8 44.Bf7+ Kxf7 45.Qxd7+ Ne7 46.Qb5 Qb2+ 47.Kf3 Qb1 48.c5 Qd1+ 49.Kg2 Qb3 50.Qa5 Bf6 51.Qa2 Qxa2 52.Nxa2 Ke6 53.Nb4 Bc3 54.Nd3 Kd5 55.Kf3 Bf6 56.Ke2 Nc6 57.Kd2 Kc4 58.Ke2 Bc3 59.f3 h6 60.e4 Ne7 61.Ke3 Bd4+ 62.Ke2 Bxc5 63.Nxc5 Kxc5 64.f5 
  -/+  (-1.59)   Depth: 36/61   00:01:06  1116MN

24 threads of 12x3GHz, 32G hash, no tbs.

Gave it three trials, all very similiar to this one, Fish was stable on Nb4 always within a few seconds.

BTW it was quite the same with SF dev. from early January (Brainfish- compile).

[Marek Soszynski]

Critter, discontinued in 2012, gets this straight away.

[pilgrimdan]

thanks ... I downloaded Critter ... and it found the move right away ...

[Ras]

You don't need a top program on that easy one. CT800, 2270 CCRL:

Code: Select all

  2/02	 0:00 	-2.02 	1.Kg1 d2 (874) 4
  3/04	 0:00 	-1.91 	1.Nc7+ Kf8 2.Qd5 Bf5 (5.944) 27
  4/04	 0:00 	-1.84 	1.Be4 d2 2.Ke2 Ne7 (21.586) 95
  5/06	 0:00 	-1.78 	1.Nb4 d2 2.Qe4+ Kf8 3.Qd3 Kg8 (71.220) 276
  6/06	 0:00 	-1.69 	1.Nb4 d2 2.Qd5 Bxh3 3.Qxd2 Bf5 (143.777) 476
  7/08	 0:00 	-1.62 	1.Nb4 d2 2.Qd5 Bxh3 3.Qxd2 Bxg2+ 4.Kxg2 Qh5 (229.057) 643
  8/09	 0:00 	-1.60 	1.Nb4 d2 2.Qd5 Qf6 3.Qxd2 Qa1+ 4.Ke2 Qa3 5.Bc6 (523.472) 985
  9/10	 0:00 	-1.60 	1.Nb4 d2 2.Qd5 Qf6 3.Qxd2 Qa1+ 4.Ke2 Qa3 5.Bc6 Bxc6 (1.005.480) 1212
 10/12	 0:02 	-1.52 	1.Nb4 Qh5 2.Qe4+ Kf7 3.Qd5+ Qxd5 4.Bxd5+ Ke7 5.Nxd3 Bxh3+ 6.Ke2 Kf6 (3.452.880) 1503  TB:20
 11/12	 0:03 	-1.54 	1.Nb4 Qh5 2.Qe4+ Kf7 3.Qd5+ Qxd5 4.Bxd5+ Ke7 5.Nxd3 Bxh3+ 6.Ke2 Kf6 (6.152.859) 1560  TB:181
 12/13	 0:07 	-1.49 	1.Nb4 Qh5 2.Qe4+ Kf7 3.Qd5+ Qxd5 4.Bxd5+ Kf6 5.Nxd3 Bxh3+ 6.Ke2 Ne7 7.Be4 (11.799.320) 1623  TB:375
 13/16	 0:14 	-1.47 	1.Nb4 Qh5 2.Qe4+ Kf7 3.Qxd3 Bxh3 4.Bxh3 Qxh3+ 5.Kg1 Qg4+ 6.Kh1 Qe6 7.Qd5 Qxd5+ 8.Nxd5 Ke6 (25.027.298) 1668  TB:1.765
 14/14	 0:31 	-1.41 	1.Nb4 Qh5 2.Qe4+ Kf8 3.Qxd3 Bxh3 4.Qd5 Qxd5 5.Nxd5 Bf5 6.Ke2 Ne7 7.Nc7 Kf7 (54.150.314) 1700  TB:5.501

[henk2]

You don't need a top program on that easy one. CT800, 2270 CCRL:

Code: Select all

  2/02	 0:00 	-2.02 	1.Kg1 d2 (874) 4
  3/04	 0:00 	-1.91 	1.Nc7+ Kf8 2.Qd5 Bf5 (5.944) 27
  4/04	 0:00 	-1.84 	1.Be4 d2 2.Ke2 Ne7 (21.586) 95
  5/06	 0:00 	-1.78 	1.Nb4 d2 2.Qe4+ Kf8 3.Qd3 Kg8 (71.220) 276
  6/06	 0:00 	-1.69 	1.Nb4 d2 2.Qd5 Bxh3 3.Qxd2 Bf5 (143.777) 476
  7/08	 0:00 	-1.62 	1.Nb4 d2 2.Qd5 Bxh3 3.Qxd2 Bxg2+ 4.Kxg2 Qh5 (229.057) 643
  8/09	 0:00 	-1.60 	1.Nb4 d2 2.Qd5 Qf6 3.Qxd2 Qa1+ 4.Ke2 Qa3 5.Bc6 (523.472) 985
  9/10	 0:00 	-1.60 	1.Nb4 d2 2.Qd5 Qf6 3.Qxd2 Qa1+ 4.Ke2 Qa3 5.Bc6 Bxc6 (1.005.480) 1212
 10/12	 0:02 	-1.52 	1.Nb4 Qh5 2.Qe4+ Kf7 3.Qd5+ Qxd5 4.Bxd5+ Ke7 5.Nxd3 Bxh3+ 6.Ke2 Kf6 (3.452.880) 1503  TB:20
 11/12	 0:03 	-1.54 	1.Nb4 Qh5 2.Qe4+ Kf7 3.Qd5+ Qxd5 4.Bxd5+ Ke7 5.Nxd3 Bxh3+ 6.Ke2 Kf6 (6.152.859) 1560  TB:181
 12/13	 0:07 	-1.49 	1.Nb4 Qh5 2.Qe4+ Kf7 3.Qd5+ Qxd5 4.Bxd5+ Kf6 5.Nxd3 Bxh3+ 6.Ke2 Ne7 7.Be4 (11.799.320) 1623  TB:375
 13/16	 0:14 	-1.47 	1.Nb4 Qh5 2.Qe4+ Kf7 3.Qxd3 Bxh3 4.Bxh3 Qxh3+ 5.Kg1 Qg4+ 6.Kh1 Qe6 7.Qd5 Qxd5+ 8.Nxd5 Ke6 (25.027.298) 1668  TB:1.765
 14/14	 0:31 	-1.41 	1.Nb4 Qh5 2.Qe4+ Kf8 3.Qxd3 Bxh3 4.Qd5 Qxd5 5.Nxd5 Bf5 6.Ke2 Ne7 7.Nc7 Kf7 (54.150.314) 1700  TB:5.501

Weaker programs often find "simple" solutions faster than top engines.
If the right move is only a few ply deep then a program that prunes less has a greater chance of finding it quicker.