Test position - Appearances are deceiving Nxd5!!

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Albert Silver
Posts: 3026
Joined: Wed Mar 08, 2006 9:57 pm
Location: Rio de Janeiro, Brazil

Test position - Appearances are deceiving Nxd5!!

Post by Albert Silver »

The following position is from analysis I made of Lahno-Kosintseva T..

[d]1br2r2/1p1bq2k/p1n2np1/3p4/5N2/1P1BP3/PB3PP1/R2Q1RK1 w - - 0 20

The strongest move is neither Bxg6+ nor Nxg6, but rather Nxd5!
"Tactics are the bricks and sticks that make up a game, but positional play is the architectural blueprint."
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zullil
Posts: 6442
Joined: Tue Jan 09, 2007 12:31 am
Location: PA USA
Full name: Louis Zulli

Re: Test position - Appearances are deceiving Nxd5!!

Post by zullil »

Albert Silver wrote:The following position is from analysis I made of Lahno-Kosintseva T..

[d]1br2r2/1p1bq2k/p1n2np1/3p4/5N2/1P1BP3/PB3PP1/R2Q1RK1 w - - 0 20

The strongest move is neither Bxg6+ nor Nxg6, but rather Nxd5!
Critter-1.4 seems to agree:

Code: Select all

23/57  03:10 1890122903 9935883  +0.32 Bxg6+ Kg7 Nxd5 Qd6 Qh5 Ne5 Nxf6 Rh8 Rfd1 Rxh5 Rxd6 Kxg6 Rb6 Bc6 Nxh5 Kxh5 Bxe5 Bxe5 Rc1 Bf6 Rc2 Kg6 Rb4 Rd8 f3 Kf7 Kf2 Ke6 Rb6 a5 f4 Kf7 a4 Kg6 Ke2 Rh8 Rc5 Bd8 Rbxc6+ bxc6 Kf3 Rh2 Rxc6+ Bf6
23/57+ 04:25 2668948690 10053332  +0.39 Nxd5 Qd6 Nxf6+ Rxf6 Qh5+ Kg8 Qh4 Kg7 Bxg6 Kxg6 Rad1 Qh2+ Qxh2 Bxh2+ Kxh2 Rf7 Rd6+ Kg5 e4 Kf4 Bc1+ Ke5 Rfd1 Rxf2 R6d5+ Kxe4 Rxd7 Re2 R7d2 Rxd2 Bxd2 Ne5 Re1+ Kd5 Rc1 Rxc1 Bxc1 Nd3 Ba3 Ke5 Kg3 Kd4
23/57+ 04:45 2872721012 10045989  +0.48 Nxd5 Qd6 Nxf6+ Rxf6 Qh5+ Kg8 Qh4 Kg7 Bxg6 Kxg6 Rad1 Qh2+ Qxh2 Bxh2+ Kxh2 Rf7 Rd6+ Kg5 e4 Kf4 Bc1+ Ke5 Rfd1 Rxf2 R6d5+ Kxe4 Rxd7 Re2 R7d2 Rxd2 Bxd2 Ne5 Re1+ Kd5 Rc1 Rxc1 Bxc1 Nd3 Ba3 Ke5 Kg3 Kd4
23/57+ 05:23 3250936362 10054608  +0.61 Nxd5 Qd6 Nxf6+ Rxf6 Qh5+ Kg8 Qh4 Kg7 Bxg6 Kxg6 Rad1 Qh2+ Qxh2 Bxh2+ Kxh2 Rf7 Rd6+ Kg5 e4 Kf4 Bc1+ Ke5 Rfd1 Rxf2 R6d5+ Kxe4 Rxd7 Re2 R7d2 Rxd2 Bxd2 Ne5 Re1+ Kd5 Rc1 Rxc1 Bxc1 Nd3 Ba3 Ke5 Kg3 Kd4
23/60  06:14 3771292026 10063729  +0.48 Nxd5 Qd6 Nxf6+ Rxf6 Qh5+ Kg8 Qh4 Kg7 Bxg6 Rh8 Bh5 Qh2+ Qxh2 Bxh2+ Kxh2 Rxh5+ Kg1 Ne5 f4 Ng4 e4 Bc6 Bxf6+ Kxf6 Rfe1 Rc5 Rac1 Rxc1 Rxc1 Bxe4 Rc8 Ke6 Rf8 Ne3 g3 Ng4 Rg8 Nf6 Rg5 Bf5 Kg2
24/60+ 06:49 4119836105 10048674  +0.57 Nxd5 Qd6 Nxf6+ Rxf6 Qh5+ Kg8 Qh4 Kg7 Bxg6 Rh8 Bh5 Qh2+ Qxh2 Bxh2+ Kxh2 Rxh5+ Kg1 Ne5 f4 Ng4 e4 Bc6 Bxf6+ Kxf6 Rfe1 Rc5 Rac1 Rxc1 Rxc1 Bxe4 Rc8 Bc6 g3 Ne3 Rf8+ Ke7 Rh8 Kf7 Rh7+ Kg6 Re7 Nd5 Re6+ Kf7 Rh6 Nc3 a4
24/71  08:51 5416168281 10194814  +0.62 Nxd5 Qd6 Nxf6+ Rxf6 Qh5+ Kg8 Qh4 Kg7 Bxg6 Rh8 Bh5 Qh2+ Qxh2 Bxh2+ Kxh2 Rxh5+ Kg1 Ne5 f4 Ng4 e4 Bc6 Bxf6+ Kxf6 Rfe1 Rc5 Rac1 Rxc1 Rxc1 Bxe4 g3 Bd5 Kf1 Kf5 Rc8 Nf6 Rf8 Ke6 Ke1 Bc6 Ke2 Be8 Ke3 Kf5
25/71  14:05 8817348587 10432830  +0.66 Nxd5 Qd6 Nxf6+ Rxf6 Qh5+ Kg8 Qh4 Kg7 Bxg6 Rh8 Bh5 Qh2+ Qxh2 Bxh2+ Kxh2 Rxh5+ Kg1 Ne5 f4 Ng4 e4 Bc6 Bxf6+ Kxf6 Rfe1 Rc5 Rac1 Rxc1 Rxc1 Bxe4 g3 Kg6 Kf1 Nf6 Ke2 b6 Ke3 Kf5 Kd4 Ng4 Rc8 Bb7 Rf8+ Nf6
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kgburcham
Posts: 2016
Joined: Sun Feb 17, 2008 4:19 pm

Re: Test position - Appearances are deceiving Nxd5!!

Post by kgburcham »

1br2r2/1p1bq2k/p1n2np1/3p4/5N2/1P1BP3/PB3PP1/R2Q1RK1 w - -

CPU0: GenuineIntel Intel64 Family 6 Model 44 Stepping 2 3373 MHz
CPU1: GenuineIntel Intel64 Family 6 Model 44 Stepping 2 3373 MHz
CPU2: GenuineIntel Intel64 Family 6 Model 44 Stepping 2 3373 MHz
CPU3: GenuineIntel Intel64 Family 6 Model 44 Stepping 2 3373 MHz
CPU4: GenuineIntel Intel64 Family 6 Model 44 Stepping 2 3373 MHz
CPU5: GenuineIntel Intel64 Family 6 Model 44 Stepping 2 3373 MHz
GUI: Tablebases with 6 pieces found! [Cache: 999 MB + internal 51.31 MB]
6 processor(s) found, POPCNT available
NUMA configuration with 1 node(s), offset 0
4096 MB Large Page Hash
Nalimov 6 men EGTB available - 999 MB cache
Engine: Houdini 2.0c Pro x64 (4096 MB)
by Robert Houdart

23/67 0:52 +0.22 1.Bxg6+ Kg7 2.Nxd5 Qd6 3.Qh5 Ne5 (909.340.754) 17258
23/67 1:10 +0.30++ 1.Nxd5 (1.220.065.110) 17244
23/67 1:20 +0.29 1.Nxd5 Qd6 2.Nxf6+ Rxf6 3.Qh5+ Kg8 (1.394.545.186) 17233
24/67 1:26 +0.29 1.Nxd5 Qd6 2.Nxf6+ Rxf6 3.Qh5+ Kg8 (1.499.189.276) 17236
25/67 2:31 +0.31 1.Nxd5 Qd6 2.Nxf6+ Rxf6 3.Qh5+ Kg8 (2.635.698.374) 17356
26/67 3:20 +0.31 1.Nxd5 Qd6 2.Nxf6+ Rxf6 3.Qh5+ Kg8 (3.500.394.341) 17440
27/67 6:19 +0.31 1.Nxd5 Qd6 2.Nxf6+ Rxf6 3.Qh5+ Kg8 (6.711.791.642) 17695
27/69 7:09 +0.31 1.Nxd5 Qd6 2.Nxf6+ Rxf6 3.Qh5+ Kg8 4.Qh4 Ne5 5.Rad1 Re6 6.Bf5 gxf5 7.Rxd6 Bxd6 8.Bxe5 Bxe5 9.Qg5+ Bg7 10.Rd1 Bc6 11.Qxf5 Rce8 12.a4 Be4 13.Qh5 Re5 14.Qg4 (7.629.347.676) 17752

multi pv
27 +0.32 1.Nxd5 Qd6 2.Nxf6+ Rxf6 3.Qh5+ Kg8 (48.057.898.458) 17225
27 +0.27 1.Bxg6+ Kg7 2.Nxd5 Qd6 3.Qh5 Ne5 (48.057.898.458) 17225
27 +0.19 1.Nxg6 Qd6 2.f4 Kg8 3.Qe1 Nb4 (48.057.898.458) 17225
27 0.00 1.Bxf6 Rxf6 2.Nxd5 Qd6 3.Nxf6+ Kg7 (48.057.898.458) 17225
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S.Taylor
Posts: 8514
Joined: Thu Mar 09, 2006 3:25 am
Location: Jerusalem Israel

Re: Test position - Appearances are deceiving Nxd5!!

Post by S.Taylor »

Albert Silver wrote:The following position is from analysis I made of Lahno-Kosintseva T..

[d]1br2r2/1p1bq2k/p1n2np1/3p4/5N2/1P1BP3/PB3PP1/R2Q1RK1 w - - 0 20

The strongest move is neither Bxg6+ nor Nxg6, but rather Nxd5!
I feel i would have thought so myself, and that it is rather elementary (even comparing the options)compared to most positions people seem to marvel about.
Why, was this breaking news from a recent game?
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Terry McCracken
Posts: 16465
Joined: Wed Aug 01, 2007 4:16 am
Location: Canada

Re: Test position - Appearances are deceiving Nxd5!!

Post by Terry McCracken »

Albert Silver wrote:The following position is from analysis I made of Lahno-Kosintseva T..

[d]1br2r2/1p1bq2k/p1n2np1/3p4/5N2/1P1BP3/PB3PP1/R2Q1RK1 w - - 0 20

The strongest move is neither Bxg6+ nor Nxg6, but rather Nxd5!
Interesting position. Looks tough for White to win after Nxd5 as Black must refuse the sacrifice. 20..Nxd5?? 21. Qh5+..Kg8 22. Qxg6+..Qg7 23. Qxg7#.

So 20..Qd6! and it's a battle with White having the edge.
Terry McCracken
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MikeGL
Posts: 1010
Joined: Thu Sep 01, 2011 2:49 pm

Re: Test position - Appearances are deceiving Nxd5!!

Post by MikeGL »

I prefer black, due to the extra piece.

But the score difference between Nxd5 and Bxg6+ is so close according to the post of kgburcham above.

So Bxg6 might also be the correct move.
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