23. Nxg6!!

[Jack Lad]

[d] 2q2bk1/1p3pp1/rnpp1np1/6N1/p1PP1N2/3Q3P/PP1B1PP1/4R1K1 w - - 5 23

Fruit just prefers Qc3 instead.

http://www.chessgames.com/perl/chessgame?gid=1477843

[swami]

Bright-CCT version finds it in 1 minute 53 seconds with clear + score:

Analysis by bright-0.4-cct1:

• 1.Nf3
  +/- (0.87) Depth: 1/1 00:00:00
  1.Ne4 Nxe4 2.Rxe4
  +/- (0.89) Depth: 1/3 00:00:00
  1.Bc3
  +/- (0.98) Depth: 1/3 00:00:00
  1.Bb4
  +/- (1.06) Depth: 1/3 00:00:00
  1.Bb4 c5
  +/- (1.02) Depth: 2/6 00:00:00
  1.Bb4 d5 2.c5
  +/- (0.86) Depth: 3/7 00:00:00
  1.a3 d5 2.c5
  +/- (0.96) Depth: 3/9 00:00:00
  1.Bb4 d5 2.Bxf8 Qxf8
  +/- (0.73) Depth: 4/9 00:00:00
  1.Bb4 d5 2.Bxf8 Qxf8
  +/- (0.73) Depth: 4/9 00:00:00
  1.Ne4 Nxe4 2.Rxe4 Qf5
  +/- (0.76) Depth: 4/10 00:00:00
  1.Ne4 Nxe4 2.Rxe4 d5 3.cxd5 Nxd5 4.Nxd5 cxd5
  +/- (0.73) Depth: 5/10 00:00:00
  1.Ne4 Nxe4 2.Rxe4 d5 3.cxd5 Nxd5 4.Nxd5 cxd5
  +/- (0.73) Depth: 6/14 00:00:00 31kN
  1.Ne4 Nxe4 2.Rxe4 d5 3.cxd5 cxd5 4.Re5 Nc4 5.Rxd5 Nxb2
  +/= (0.49) Depth: 7/19 00:00:00 88kN
  1.Bc3 Qf5 2.Qxf5 gxf5 3.b3 axb3 4.axb3 Ra2 5.d5 cxd5 6.Bxf6 gxf6
  +/= (0.53) Depth: 7/20 00:00:00 181kN
  1.Bc3 Qf5 2.Qxf5 gxf5 3.b3 axb3 4.axb3 Ra2 5.d5 cxd5 6.Bxf6 gxf6
  +/= (0.53) Depth: 8/20 00:00:00 308kN
  1.Bc3 Qf5 2.Qxf5 gxf5 3.c5 dxc5 4.dxc5 Bxc5 5.Nd3 Bd6 6.Bxf6 gxf6
  = (0.22) Depth: 9/24 00:00:00 755kN
  1.Nxg6 fxg6 2.Qxg6 d5 3.Qf7+ Kh8 4.Ne6 Ra8 5.cxd5 Nbxd5 6.Nxf8 Qxf8 7.Qxb7 Re8 8.Qxc6 Rxe1+ 9.Bxe1
  = (0.25) Depth: 9/30 00:00:00 1087kN
  1.h4 Qf5 2.Rc1 Ra8 3.Qxf5 gxf5 4.h5 c5 5.dxc5 dxc5
  +/= (0.34) Depth: 9/30 00:00:00 1426kN
  1.Qc2 d5 2.c5 Nc4 3.Nd3 Qf5 4.Bf4 Nh5 5.g4
  +/= (0.45) Depth: 9/30 00:00:00 1779kN
  1.Qc3 d5 2.c5 Nc4 3.Nd3 Qf5 4.Bf4 Nh5 5.g4
  +/= (0.50) Depth: 9/30 00:00:00 2604kN
  1.Qc3 d5 2.c5 Nc4 3.Nd3 Qf5 4.Bf4 b6 5.g4 Qd7
  +/= (0.53) Depth: 10/30 00:00:00 2911kN
  1.Qc3 d5 2.c5 Nc4 3.Nd3 Qf5 4.Bf4 b6 5.b4 axb3 6.axb3
  +/= (0.51) Depth: 11/30 00:00:01 4291kN
  1.Qc3 d5 2.c5 Nc4 3.Nd3 Qf5 4.a3 Ra8 5.Bf4 Ne4 6.Nxe4 dxe4 7.Qxc4 exd3
  +/= (0.59) Depth: 12/37 00:00:01 8362kN
  1.Qc3 d5 2.c5 Nc4 3.Nd3 b6 4.Nb4 Ra8 5.cxb6 Qb7 6.Nd3 Qxb6 7.Bf4
  +/= (0.39) Depth: 13/39 00:00:02 13416kN
  1.c5 Nbd5 2.Qc4 Qf5 3.Nd3 Ra8 4.a3 dxc5 5.Re5 b5 6.Qc2 Qd7 7.Nxc5 Bxc5 8.Qxc5
  +/= (0.42) Depth: 13/39 00:00:04 22028kN
  1.c5 Nbd5 2.Qc4 Qd7 3.Nd3 a3 4.b4 Ra8 5.Kh1 Be7 6.Nf3 Kh8 7.Bf4 dxc5 8.bxc5 Nxf4 9.Nxf4
  +/= (0.38) Depth: 14/39 00:00:09 52887kN
  1.c5 Nbd5 2.Qc4 Qd7 3.Nd3 a3 4.b4 Ra8 5.Bf4 Nh5 6.Bh2 Be7 7.Ne4 dxc5 8.bxc5
  +/= (0.40) Depth: 15/44 00:00:31 160mN
  1.c5 Nbd5 2.Qc4 Qd7 3.Nd3 a3 4.b4 Ra8 5.Bf4 Nh5 6.Bh2 Be7 7.Ne4 dxc5 8.bxc5 Qf5
  +/= (0.38) Depth: 16/44 00:00:34 195mN
  1.Qc2 d5 2.c5 Nc4 3.Nd3 b6 4.Ne5 Qf5 5.Qxf5 gxf5 6.Nxc4 dxc4 7.a3 bxc5 8.dxc5 Bxc5 9.Bc3 Nd5 10.Re8+ Bf8 11.Bd4 c5
  +/= (0.44) Depth: 16/57 00:00:51 289mN
  1.Qc2 d5 2.c5 Nc4 3.Nd3 b6 4.Ne5 Qf5 5.Qxf5 gxf5 6.Nxc4 dxc4 7.a3 bxc5 8.dxc5 Bxc5 9.Bc3 Rb6 10.Bxf6 gxf6 11.Re8+ Kg7
  +/= (0.44) Depth: 17/57 00:01:10 395mN
  1.Nxg6 fxg6 2.Qxg6 d5 3.h4 Nxc4 4.Re6 Qxe6 5.Nxe6 Nxd2 6.Nd8 c5 7.Qf7+ Kh7 8.Qxf8 cxd4 9.Qc5 Ra8 10.Nxb7 d3 11.Nd6
  +- (2.66) Depth: 17/57 00:01:53 627mN
  1.Nxg6 fxg6 2.Qxg6 d5 3.h4 Nxc4 4.Re6 Qxe6 5.Nxe6 Nxd2 6.Nd8 c5 7.Qf7+ Kh7 8.Qxf8 cxd4 9.Qc5 d3 10.Qd4 Nde4 11.Qxd3 Rb6
  +- (2.80) Depth: 18/57 00:02:48 919mN
  1.Nxg6 fxg6 2.Qxg6 d5 3.h4 Nxc4 4.Re6 Qxe6 5.Nxe6 Nxd2 6.Nd8 c5 7.Qf7+ Kh7 8.Qxf8 cxd4 9.Qc5 d3 10.Qd4 Nde4 11.Qxd3 Rb6 12.f3
  +- (2.85) Depth: 19/63 00:04:14 1396mN
  1.Nxg6 fxg6 2.Qxg6 d5 3.h4 Nxc4 4.Re6 Qxe6 5.Nxe6 Nxd2 6.Nd8 c5 7.Qf7+ Kh7 8.Qxf8 cxd4 9.Qc5 Nc4 10.Qxd4 Rb6 11.b3 axb3 12.Qd3+ Ne4 13.Qxd5
  +- (3.04) Depth: 20/74 00:07:26 2453mN

[BBauer]

Stockfish opt with some parameters changed thinks of nothing else.

Code: Select all

FEN: 2q2bk1/1p3pp1/rnpp1np1/6N1/p1PP1N2/3Q3P/PP1B1PP1/4R1K1 w - - 5 23 

Stockfish_12_opt_my:
   6	00:00	      12.119	247.326	+4,11	Nf4xg6 f7xg6 Qd3xg6 Qc8d7 Ng5e6 Nb6xc4
   7	00:00	      29.543	256.895	+3,80	Nf4xg6 f7xg6 Qd3xg6 Qc8d7 Ng5e6 Nb6xc4 Bd2g5
   8	00:00	      49.269	311.829	+3,70	Nf4xg6 f7xg6 Qd3xg6 Qc8d7 b2b3 a4xb3 a2xb3 Ra6a2
   9	00:00	     195.213	753.718	+5,35	Nf4xg6 f7xg6 Qd3xg6 d6d5 Re1e6 Nb6d7 c4c5 Kg8h8 Ng5f7+ Kh8g8 Re6e1
  10	00:00	     280.905	861.671	+4,98	Nf4xg6 d6d5 c4xd5 f7xg6 Qd3xg6 c6xd5 Re1e6 Nb6d7 Re6e1 Bf8d6
  11	00:00	     431.819	988.144	+5,07	Nf4xg6 d6d5 c4xd5 f7xg6 Qd3xg6 c6xd5 Re1e6 Nb6d7 Re6e1 Kg8h8 Ng5f7+ Kh8g8 Bd2f4
  12	00:01	   1.798.671	1.395.400	+4,76	Nf4xg6 f7xg6 Qd3xg6 d6d5 Re1e6 Nb6d7 c4c5 b7b6 c5xb6 Ra6xb6 Bd2c3 Kg8h8 Ng5f7+ Kh8g8 h3h4
  13	00:02	   2.579.710	1.408.907	+4,52	Nf4xg6 f7xg6 Qd3xg6 d6d5 Re1e6 Nb6d7 c4c5 b7b6 c5xb6 Ra6xb6 Bd2c3 Bf8b4 Ng5f7 Bb4xc3
  14	00:03	   4.114.779	1.466.944	+4,64	Nf4xg6 f7xg6 Qd3xg6 d6d5 Re1e6 Nb6d7 Re6e3 Kg8h8 Re3e2 Ra6b6 c4xd5 Rb6xb2 Ng5f7+ Kh8g8 d5xc6 Rb2xd2
  15	00:05	   8.234.492	1.541.173	+4,58	Nf4xg6 f7xg6 Qd3xg6 d6d5 Re1e6 Nb6d7 Re6e3 Qc8a8 c4xd5 c6xd5 Re3e1 Ra6c6 b2b3 a4xb3 a2xb3
  16	00:16	  25.438.010	1.607.965	+5,39	Nf4xg6 f7xg6 Qd3xg6 d6d5 c4c5 a4a3 b2b3 Nb6d7 h3h4 b7b6 c5xb6 Nd7xb6 Re1e6 Nb6d7 h4h5 c6c5 d4xc5
  17	00:39	  63.922.220	1.625.196	+5,33	Nf4xg6 f7xg6 Qd3xg6 d6d5 c4c5 a4a3 b2b4 Nb6d7 h3h4 Ra6a7 h4h5 b7b5 h5h6 Nd7b8 Ng5e6 Kg8h8 h6xg7+ Bf8xg7
  18	00:51	  83.371.532	1.624.194	+5,07	Nf4xg6 f7xg6 Qd3xg6 d6d5 c4c5 a4a3 b2b3 Nb6d7 h3h4 b7b6 c5xb6 Nd7xb6 Re1e6 Nb6d7 Qg6f5 Nd7b6 Bd2f4 Bf8b4 Bf4e5
  19	01:28	 142.595.633	1.607.272	+5,37	Nf4xg6 f7xg6 Qd3xg6 d6d5 c4c5 Nb6d7 h3h4 Ra6a7 h4h5 b7b5 h5h6 Nd7b8 Bd2f4 Kg8h8 Ng5e6 Ra7b7 h6xg7+ Bf8xg7 Re1e3 Nb8a6
  20	02:48	 271.154.494	1.613.429	+5,25	Nf4xg6 f7xg6 Qd3xg6 d6d5 c4c5 Nb6d7 h3h4 b7b5 h4h5 Ra6a7 h5h6 Nd7xc5 d4xc5 Bf8xc5 Re1e6 Qc8f8 Re6xc6 Bc5xf2+ Kg1f1 Qf8e8 Rc6xf6 Qe8xg6 Rf6xg6

[royb]

Stockfish 1.2 sees this quite easily on a 1.67 GHz single CPU system:

2 +3.80 23.Nxf7 Qf5 (4.39)
3 +3.05 23.Nxf7 Qf5 24.Qxf5 gxf5 (4.93)
4 +1.35 23.Nxf7 Kxf7 24.c5 Qf5 (5.52)
4 +1.62 23.c5 dxc5 24.Nxf7 cxd4 (5.55)
5 +2.05 23.c5 Nbd5 24.cxd6 Bxd6 25.Nxf7 (5.83)
5 +2.92 23.Nxf7 Kxf7 24.Nxg6 Nxc4 25.Bc1 (5.84)
6 +1.58 23.Nxf7 Qf5 24.Qe2 Kxf7 25.c5 Ne4 (6.04)
7 +1.50 23.Nxf7 Qf5 24.Qe2 Kxf7 25.c5 dxc5 26.Ne6 (6.27)
8 +1.31 23.Nxf7 Qf5 24.Nd8 Qxd3 25.Nxd3 Nxc4 26.Bc3 b5 27.Ne6 (6.60)
8 +2.74 23.Nxg6 fxg6 24.Qxg6 d5 25.Re6 Nbd7 26.c5 b6 (7.44)
9 +2.31 23.Nxg6 fxg6 24.Qxg6 d5 25.Re6 Nbd7 26.c5 a3 27.bxa3 Rxa3 (7.70)
10 +1.58 23.Nxg6 fxg6 24.Qxg6 d5 25.Re6 Nbd7 26.c5 Kh8 27.Bb4 b6 (8.06)
11 +1.47 23.Nxg6 fxg6 24.Qxg6 d5 25.Re6 Nbd7 26.c5 b6 27.cxb6 Rxb6 28.Bc3 Kh8 (9.24)
12 +1.70 23.Nxg6 fxg6 24.Qxg6 d5 25.Qf7+ Kh8 26.cxd5 cxd5 27.Ne6 Nbd7 28.Nf4 Qc2 29.Ng6+ Kh7 30.Nxf8+ Nxf8 31.Re7 (11.63)
13 +1.64 23.Nxg6 fxg6 24.Qxg6 d5 25.Qf7+ Kh8 26.cxd5 cxd5 27.Ne6 Nbd7 28.Nf4 Qc2 29.Be3 Qxb2 30.Ng6+ Kh7 31.Nxf8+ Nxf8 32.Qxf8 Qxa2 (15.42)
14 +1.41 23.Nxg6 fxg6 24.Qxg6 d5 25.Qf7+ Kh8 26.cxd5 cxd5 27.Ne6 Nbd7 28.Bg5 Ne4 29.Be7 Rxe6 30.Qxe6 Qc2 31.Kh2 (26.16)
15 +1.84 23.Nxg6 fxg6 24.Qxg6 d5 25.Re6 Nbd7 26.Bf4 c5 27.cxd5 cxd4 28.d6 Rb6 29.b3 axb3 30.axb3 Qa8 31.Bh2 (47.42)
16 +1.72 23.Nxg6 fxg6 24.Qxg6 d5 25.c5 Nbd7 26.Bf4 b6 27.Re6 a3 28.b4 Ra4 29.cxb6 Rxb4 30.Bc7 Rxd4 31.Rxc6 (70.27)
17 +2.07 23.Nxg6 fxg6 24.Qxg6 d5 25.c5 Nbd7 26.Bf4 b6 27.Re6 a3 28.b4 bxc5 29.bxc5 Ra4 30.Be3 Ra6 31.Bd2 (109.76)

[rightrook]

Good test....thanks...!

Hiarcs 11.2 finds it right away....the first move displayed....!!

regards

Robert

[Dirt]

Fruit just prefers Qc3 instead.

At least one Fruit derivative, Toga 1.4 beta5c, does prefer Nxg6 over Qc3. At least it does if you give it a factor of 1000 longer to think about it than Stockfish 1.2 needs.

[Sean Evans]

[D] 2q2bk1/1p3pp1/rnpp1np1/6N1/p1PP1N2/3Q3P/PP1B1PP1/4R1K1 w - - 0 1

Analysis by Shredder 11:

1.Qc3 Ra8 2.Nd3 Qf5 3.g4 Qd7 4.Bf4 Re8 5.b3 Rxe1+ 6.Qxe1 Be7 7.Qe3 axb3 8.axb3 Qe8 9.Qe1 Qd7
+/= (0.62) Depth: 20/49 00:21:24 492mN
(Sean, 10.03.2009)

Shredder grabbed Qc3 instantly and wouldn't let go even after 20 minutes of analysis

[Cubeman]

PF3 with Hiarcs 12.1 only 16 seconds to find 1.Nxg6 with +1.03 score.It is hard for black to defend against the Rook invading on the e file and it is only a matter of time before Black is crushed.