Test position: beautiful positional sacrifice

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maac
Posts: 13
Joined: Sat Dec 07, 2013 6:13 pm

Test position: beautiful positional sacrifice

Post by maac »

[d]r1bq1rk1/1pp2pbp/p2ppnp1/n2P4/2P5/P1N3P1/1P1NPPBP/R1BQ1RK1 b - - 0 10


from game Grandelius - Ipatov, (2012) here black plays the beautiful Rb8!!,
Houdini 4 finds it at depth 24 (& 26). Which other engine is capable of find it?

PS. It's because it and other subtleties that i prefer Houdini over the others, it's a marvel!
arjuntemurnikar
Posts: 204
Joined: Tue Oct 15, 2013 10:22 pm
Location: Singapore

Re: Test position: beautiful positional sacrifice

Post by arjuntemurnikar »

Sting SF 4 finds Rb8 at depth 14 but then changes to Nd7.

Code: Select all

 1 [+0.04]  10.... e5  (0.04)
 2 [-0.04]  10.... Ng4 11.e3 Bxc3 12.bxc3  (0.04)
 3 [-0.16]  10.... exd5 11.cxd5 Bf5  (0.04)
 4 [-0.08]  10.... Ng4 11.e3 f5 12.Qc2  (0.04)
 5 [-0.04]  10.... c6 11.Nb3 Nxc4 12.dxc6 bxc6 13.Bxc6  (0.05)
 6 [-0.12]  10.... Bd7  (0.05)
 6 [-0.04]  10.... Bd7 11.e4 Nh5 12.Re1 Bxc3 13.bxc3  (0.06)
 7 [+0.04]  10.... Bd7  (0.07)
 7 [+0.08]  10.... Bd7 11.Qc2 exd5 12.cxd5 Ng4 13.h3 Ne5 14.b4  (0.07)
 8 [-0.04]  10.... c6  (0.08)
 8 [+0.12]  10.... Ng4 11.Qa4 Bxc3 12.bxc3 c5 13.dxc6 Nxc6 14.Bxc6 bxc6 15.Qxc6  (0.10)
 9 [+0.00]  10.... Bd7  (0.11)
 9 [+0.12]  10.... Bd7 11.Qc2 Ng4 12.Nf3 exd5 13.cxd5 Ne5 14.Bf4 Nxf3+ 15.Bxf3 Nc4 16.e4  (0.13)
10 [+0.20]  10.... Bd7  (0.18)
10 [+0.04]  10.... c6  (0.19)
10 [+0.24]  10.... Ng4 11.Qa4 Bxc3 12.bxc3 c5 13.dxc6 Nxc6 14.Bxc6 bxc6 15.Qxc6 Ra7 16.Bb2  (0.21)
11 [+0.24]  10.... exd5 11.cxd5 Bd7 12.Qc2 c6 13.b4 Nxd5 14.Bxd5 cxd5 15.bxa5 Qxa5 16.Ndb1 Rfc8  (0.29)
12 [+0.16]  10.... exd5  (0.31)
12 [+0.08]  10.... exd5 11.cxd5 Bd7 12.Nb3 Nc4 13.Qc2 Ng4 14.h3 Nf6 15.Bg5 c6 16.e4 h6 17.dxc6 bxc6  (0.57)
13 [+0.20]  10.... exd5  (0.74)
13 [+0.24]  10.... Bd7 11.Qc2 exd5 12.cxd5 c6 13.dxc6 Nxc6 14.Nf3 Rc8 15.e4 Be6 16.Bf4 Bc4  (0.82)
14 [+0.12]  10.... Rb8  (1.22)
14 [+0.08]  10.... Rb8 11.Qa4 c5 12.Nb3 Nxb3 13.Qxb3 b5 14.Bg5 Bd7 15.cxb5 axb5 16.Qc2 h6 17.Bd2 b4 18.axb4 Rxb4 19.dxe6 Bxe6  (1.47)
15 [-0.04]  10.... Rb8  (1.60)
15 [-0.12]  10.... Rb8 11.Qa4 c5 12.Nb3 Nxb3 13.Qxb3 b5 14.Bg5 Bd7 15.cxb5 axb5 16.Qc2 h6 17.Bd2 Re8 18.Rfe1 exd5 19.Nxd5 Be6 20.e4 Nxd5 21.exd5  (2.55)
16 [+0.00]  10.... Rb8  (3.17)
16 [-0.08]  10.... Rb8 11.e4 Re8 12.Qa4 c5 13.Nb3 Nxb3 14.Qxb3 b5 15.Bg5 Bd7 16.Rfb1 bxc4 17.Qxc4 exd5 18.Nxd5 h6 19.Bf4 Nxd5 20.Qxd5  (3.61)
17 [+0.04]  10.... Rb8  (4.53)
17 [+0.24]  10.... Nd7 11.Qa4 c5 12.Nb3 Nxb3 13.Qxb3 Qb6 14.Qc2 Ne5 15.dxe6 fxe6 16.Ne4 Bd7 17.Rd1 Nf7 18.Rb1 Rac8 19.Bf4  (9.24)
18 [+0.12]  10.... Re8  (11.71)
18 [+0.12]  10.... Re8 11.Qa4 c5 12.dxc6 Nxc6 13.Bxc6 bxc6 14.Qxc6 Rb8 15.c5 dxc5 16.Qxc5 Nd5 17.Nde4 Nxc3 18.Nxc3 Bd4 19.Qc4 e5  (16.39)
19 [+0.12]  10.... Re8 11.Qa4 c5 12.dxc6 Nxc6 13.Bxc6 bxc6 14.Qxc6 Rb8 15.c5 dxc5 16.Qxc5 Nd5 17.Nde4 Nxc3 18.Nxc3 Bd4 19.Qc4 e5 20.e3 Be6 21.Qxa6 Bxc3  (18.26)
20 [+0.04]  10.... Re8  (19.61)
20 [+0.12]  10.... exd5 11.cxd5 Ng4 12.Qa4 c5 13.dxc6 bxc6 14.Bxc6 Nxc6 15.Qxc6 Rb8 16.Nde4 Rb6 17.Qa8 Bb7  (46.84)
21 [+0.20]  10.... exd5  (52.48)
21 [+0.28]  10.... Nd7 11.Qa4 c5 12.Nb3 Nxb3 13.Qxb3 Qb6 14.Qc2 Nf6 15.h3 Bd7 16.e4 Qc7 17.Bg5 h6 18.Be3 b5 19.e5  (65.47)
22 [+0.16]  10.... Nd7  (75.00)
22 [+0.20]  10.... Nd7 11.Qc2 Ne5 12.b3 c6 13.Bb2 Rb8 14.dxc6 Naxc6 15.Na4 b5 16.Bxc6 Nxc6 17.Bxg7 Kxg7 18.cxb5 Nd4 19.Qd3 Nxb5 20.Nc3  (130.22)
24 [+0.12]  10.... Nd7  (161.60)
Latest Stockfish (190114) doesn't bother about Rb8 (at least up till depth 25), instead suggests Nd7.

Code: Select all

 1 [+0.31]  10.... exd5 11.cxd5  (0.00)
 2 [+0.29]  10.... c6 11.e4 exd5 12.cxd5 cxd5 13.exd5  (0.00)
 3 [+0.00]  10.... exd5 11.Nxd5 Nxd5 12.cxd5  (0.01)
 4 [+0.21]  10.... exd5 11.cxd5 Bg4 12.b4  (0.01)
 5 [+0.03]  10.... Bd7 11.e4 c6 12.Re1 exd5 13.cxd5 cxd5 14.exd5  (0.01)
 7 [-0.09]  10.... Bd7 11.e4 c6 12.Re1 Re8 13.dxe6 Bxe6  (0.02)
 8 [-0.07]  10.... c6 11.e4 Bd7 12.Re1 Re8 13.e5 dxe5 14.d6  (0.05)
 9 [+0.07]  10.... Bd7 11.Qc2 exd5 12.cxd5 b5 13.e4 c6 14.b4 Nc4 15.Nxc4 bxc4  (0.08)
10 [+0.27]  10.... Bd7 11.Qc2 exd5 12.cxd5 b5 13.e4 c6 14.b4 Nc4 15.Nxc4 bxc4 16.Bg5  (0.12)
11 [+0.14]  10.... Bd7 11.Qc2 exd5 12.cxd5 b5 13.b3 c5 14.e4 Ng4 15.Nf3 Re8  (0.16)
12 [+0.25]  10.... Bd7 11.Qc2 exd5 12.cxd5 b5 13.b3 c5 14.b4 cxb4 15.axb4 Nc4 16.e4 Re8 17.Nb3  (0.25)
14 [+0.12]  10.... Nd7 11.Qa4 c6 12.Nde4 Ne5 13.dxc6 Nexc4 14.Bg5 Qc7 15.Nf6+ Bxf6 16.Bxf6 b5 17.Qc2 Nxc6 18.b3 N4e5 19.Rad1 Bd7  (0.87)
16 [+0.34]  10.... Nd7 11.Qa4 c6 12.Nde4 Ne5 13.dxc6 Nexc4 14.Bg5 Qc7 15.Nf6+ Bxf6 16.Bxf6 b5 17.Qc2 Nxc6 18.b3 N4e5 19.Ne4 Bd7 20.Bxe5 dxe5 21.Nf6+  (2.15)
17 [+0.28]  10.... Nd7 11.Qa4 c6 12.Nde4 Nxc4 13.Qxc4 cxd5 14.Nxd5 exd5 15.Qxd5 Nf6 16.Qd3 Nxe4 17.Bxe4 Re8 18.Qf3 Qf6 19.Bxb7 Bxb7 20.Qxb7  (2.80)
18 [+0.20]  10.... Nd7 11.Qa4 c6 12.Nde4 Nxc4 13.Qxc4 cxd5 14.Nxd5 exd5 15.Qxd5 Nf6 16.Qd3 Nxe4 17.Bxe4 Re8 18.Qf3 Qf6 19.Bxb7 Bxb7 20.Qxb7 Qe5  (3.04)
18 [+0.12]  10.... Nd7 11.Qa4 c6 12.Nde4 Nxc4 13.Qxc4 cxd5 14.Nxd5 exd5 15.Qxd5 Nf6 16.Qd3 Nxe4 17.Bxe4 Re8 18.Qf3 Qf6 19.Bxb7  (3.45)
18 [+0.36]  10.... Nd7 11.Qa4 c6 12.Nde4 Nxc4 13.Qxc4 cxd5 14.Nxd5 exd5 15.Qxd5 Nf6 16.Nxf6+ Qxf6 17.Rd1 Re8 18.Qxd6 Rxe2 19.Qd8+ Qxd8 20.Rxd8+ Bf8 21.Bh6  (4.66)
18 [+0.21]  10.... Nd7 11.Qa4 c6 12.Nde4 Nxc4 13.Qxc4 exd5 14.Nxd5 Ne5 15.Qb3 Be6 16.Qxb7 Bxd5 17.Rd1 Nc4 18.Bg5 Qb8 19.Qxb8 Rfxb8 20.Nf6+ Bxf6 21.Bxf6 Bxg2  (5.14)
21 [+0.29]  10.... Nd7 11.Qa4 c6 12.Nde4 Nxc4 13.Qxc4 exd5 14.Nxd5 Ne5 15.Qb3 Be6 16.Nec3 b5 17.Rd1 cxd5 18.Nxd5 Re8 19.a4 Bg4 20.Nc3 Rb8 21.axb5 axb5 22.Ne4  (19.73)
21 [+0.35]  10.... Nd7 11.Qa4 c6 12.Nde4 Nxc4 13.Qxc4 exd5 14.Nxd5 Ne5 15.Qb3 Be6 16.Nec3 b5 17.Rd1 cxd5 18.Bxd5 Bxd5 19.Rxd5 Qc7 20.a4 bxa4 21.Rxa4 Rfc8 22.Rda5 Rab8 23.Qd5 Nc4  (23.42)
22 [+0.27]  10.... Nd7 11.Qa4 c6 12.Nde4 Nxc4 13.Qxc4 exd5 14.Nxd5 Ne5 15.Qb3 Be6 16.Nec3 b5 17.Rd1 cxd5 18.Bxd5 Bxd5 19.Rxd5 Qc7 20.a4  (24.61)
22 [+0.19]  10.... Nd7 11.Qa4  (25.97)
22 [+0.32]  10.... Nd7 11.Qc2 Ne5 12.b3 exd5 13.cxd5 Bd7 14.Qa2 b5 15.Bb2 Qg5 16.Rad1 Qh6 17.Nf3 Nxf3+ 18.Bxf3 Rae8 19.Ne4 f5 20.Bxg7 Qxg7  (37.76)
23 [+0.24]  10.... Nd7 11.Qc2 Ne5 12.b3 exd5 13.cxd5 Bd7  (43.42)
23 [+0.32]  10.... Nd7 11.Qc2 Ne5 12.b3 exd5 13.cxd5 c5 14.Bb2 f5 15.Nd1 f4 16.b4 Bf5 17.Qc1 f3 18.Bxf3 cxb4 19.axb4 Rc8 20.Bc3 Nac4  (52.45)
24 [+0.24]  10.... Nd7 11.Qc2 Ne5 12.b3 exd5 13.cxd5 c5 14.Bb2 f5 15.b4 Nac4 16.Nxc4 Nxc4 17.bxc5 dxc5  (55.23)
User avatar
AdminX
Posts: 6340
Joined: Mon Mar 13, 2006 2:34 pm
Location: Acworth, GA

Re: Test position: beautiful positional sacrifice

Post by AdminX »

Here are the results I received from Stockfish Syzygy Dev at depth 33

Code: Select all


r1bq1rk1/1pp2pbp/p2ppnp1/n2P4/2P5/P1N3P1/1P1NPPBP/R1BQ1RK1 b - - 0 1

Analysis by Stockfish 200114 64:

1. +/=  (0.31): 10...exd5 11.cxd5 Nd7 12.Qc2 Ne5 13.b3 c5 14.Bb2 f5 15.e3 Bd7 16.Rab1 Rc8 17.Ne2 b5 18.Rfc1 Re8 19.Bc3 b4 20.Bxe5 dxe5 21.Qa2 e4 22.axb4 cxb4 23.Rxc8 Bxc8 24.Nc4 Nb7 25.Qxa6 Qxd5 26.Nb6 Qc6 27.Qa4 Qxa4 

2. +/=  (0.31): 10...Nd7 11.Qc2 Ne5 12.b3 exd5 13.cxd5 c5 14.Bb2 f5 15.e3 Bd7 16.Rab1 Rc8 17.Ne2 b5 18.Rfc1 Re8 19.Bc3 b4 20.Bxe5 dxe5 21.Qa2 e4 22.axb4 cxb4 23.Rxc8 Bxc8 24.Nc4 Nb7 25.Qxa6 Qxd5 26.Nb6 Qc6 27.Qa4 Qxa4 

3. +/=  (0.31): 10...Ng4 11.Qc2 Ne5 12.b3 exd5 13.cxd5 c5 14.Bb2 f5 15.e3 Bd7 16.Rab1 Rc8 17.Ne2 b5 18.Rfc1 Re8 19.Bc3 b4 20.Bxe5 dxe5 21.Qa2 e4 22.axb4 cxb4 23.Rxc8 Bxc8 24.Nc4 Nb7 25.Qxa6 Qxd5 26.Nb6 Qc6 27.Qa4 Qxa4 

"Good decisions come from experience, and experience comes from bad decisions."
__________________________________________________________________
Ted Summers
Tennison
Posts: 183
Joined: Sat Nov 26, 2011 2:02 pm

Re: Test position: beautiful positional sacrifice

Post by Tennison »

Thorgal dev 125.1 :(depth 19)


{Thorgal dev 125.1 : 1)} 10... Rb8 11. e4 c6 12. dxc6 Nxc6 13. Nf3 Ng4 14. Qc2 Qb6 15. h3 Nge5 16. Be3 Nxf3+ 17. Bxf3 Nd4 18. Bxd4 Qxd4 19. Rfd1 Qb6 20. Kf1 Bd7 {0.11/19}

{Thorgal dev 125.1 : 2)} 10... c5 11. Rb1 Qc7 12. b3 exd5 13. Nxd5 Nxd5 14. Bxd5 Nc6 15. Bb2 Bg4 16. f3 Bh3 17. Re1 Bd7 18. Bxg7 Kxg7 19. f4 Qa5 20. Qc1 Rfe8 {0.12/19}

{Thorgal dev 125.1 : 3)} 10... Nd7 11. Qc2 Ne5 12. b3 exd5 13. cxd5 Re8 14. Bb2 h5 15. Rac1 c5 16. dxc6 Naxc6 17. Nd5 h4 18. f4 {0.12/18}

Thorgal finds it before depth 19 but changes to c5 or Nd7 and return to Rb8 at depth 19.
zullil
Posts: 6442
Joined: Tue Jan 09, 2007 12:31 am
Location: PA USA
Full name: Louis Zulli

Re: Test position: beautiful positional sacrifice

Post by zullil »

AdminX wrote:Here are the results I received from Stockfish Syzygy Dev at depth 33

Code: Select all


r1bq1rk1/1pp2pbp/p2ppnp1/n2P4/2P5/P1N3P1/1P1NPPBP/R1BQ1RK1 b - - 0 1

Analysis by Stockfish 200114 64:

1. +/=  (0.31): 10...exd5 11.cxd5 Nd7 12.Qc2 Ne5 13.b3 c5 14.Bb2 f5 15.e3 Bd7 16.Rab1 Rc8 17.Ne2 b5 18.Rfc1 Re8 19.Bc3 b4 20.Bxe5 dxe5 21.Qa2 e4 22.axb4 cxb4 23.Rxc8 Bxc8 24.Nc4 Nb7 25.Qxa6 Qxd5 26.Nb6 Qc6 27.Qa4 Qxa4 

2. +/=  (0.31): 10...Nd7 11.Qc2 Ne5 12.b3 exd5 13.cxd5 c5 14.Bb2 f5 15.e3 Bd7 16.Rab1 Rc8 17.Ne2 b5 18.Rfc1 Re8 19.Bc3 b4 20.Bxe5 dxe5 21.Qa2 e4 22.axb4 cxb4 23.Rxc8 Bxc8 24.Nc4 Nb7 25.Qxa6 Qxd5 26.Nb6 Qc6 27.Qa4 Qxa4 

3. +/=  (0.31): 10...Ng4 11.Qc2 Ne5 12.b3 exd5 13.cxd5 c5 14.Bb2 f5 15.e3 Bd7 16.Rab1 Rc8 17.Ne2 b5 18.Rfc1 Re8 19.Bc3 b4 20.Bxe5 dxe5 21.Qa2 e4 22.axb4 cxb4 23.Rxc8 Bxc8 24.Nc4 Nb7 25.Qxa6 Qxd5 26.Nb6 Qc6 27.Qa4 Qxa4 

Stockfish (8 threads, 4 GB hash, MultiPV=1) finally switches at depth 41:

Code: Select all

info depth 41 seldepth 65 score cp -23 nodes 156970800266 nps 8009674 time 19597650 multipv 1 pv a8b8 b2b4 a5c4 d2c4 f6d5 c3d5 g7a1 c1h6 a1g7 h6g7 g8g7 d5f4 h7h5 e2e4 c8d7 d1a1 e6e5 f4d5 d7b5 a1c3 h5h4 f1c1 b5c4 c3c4 c7c6 d5e3 f8h8 c1d1 d8f6 c4c3 b8c8 e3c4 c8d8 c3d2 c6c5 c4b6 f6e6 b6d5 d8c8 g2f3 h4g3
info depth 42 currmove a8b8 currmovenumber 1
info depth 42 seldepth 65 score cp -15 lowerbound nodes 161870524717 nps 8012539 time 20202149 multipv 1 pv a8b8 b2b4
info depth 42 currmove a8b8 currmovenumber 1
info depth 42 currmove a5b3 currmovenumber 6
info depth 42 currmove f6g4 currmovenumber 7
info depth 42 seldepth 65 score cp -31 upperbound nodes 174653338316 nps 8023045 time 21768958 multipv 1 pv a8b8 b2b4 f6d5 c4d5 g7c3 a1a2 c3d2 c1d2 a5c4 d2h6 b7b5 h6f8 d8f8 e2e4 e6d5 e4d5 c8d7 d1d4
info depth 42 currmove a8b8 currmovenumber 1
info depth 42 currmove e6e5 currmovenumber 9
info depth 42 currmove d8e7 currmovenumber 10
info depth 42 currmove d8d7 currmovenumber 16
info depth 42 currmove g7h6 currmovenumber 17
info depth 42 currmove h7h5 currmovenumber 18
info depth 42 currmove c7c5 currmovenumber 19
info depth 42 currmove f6e8 currmovenumber 20
info depth 42 currmove a8a7 currmovenumber 21
info depth 42 currmove a5c6 currmovenumber 22
info depth 42 currmove g6g5 currmovenumber 23
info depth 42 currmove c8d7 currmovenumber 24
info depth 42 currmove g8h8 currmovenumber 25
info depth 42 currmove g7h8 currmovenumber 26
info depth 42 currmove f6d5 currmovenumber 27
info depth 42 currmove a5c4 currmovenumber 28
info depth 42 seldepth 72 score cp -18 nodes 187373293586 nps 8052744 time 23268253 multipv 1 pv a8b8 b2b4 a5c4 d2c4 f6d5 c3d5 g7a1 c1h6 a1g7 h6g7 g8g7 d5f4 c8d7 d1d2 d7b5 c4a5 c7c6 f1c1 d6d5 f4d3 b5d3 d2d3 d8f6 d3d2 e6e5 a5b3 f8e8 b3c5 e8e7 g2h3 b8e8 e2e3 e5e4 a3a4 e8d8 a4a5 f6e5 c1d1 e5f6 h3g2
info depth 43 currmove a8b8 currmovenumber 1
info depth 43 seldepth 72 score cp -10 lowerbound nodes 195463482707 nps 8059396 time 24252867 multipv 1 pv a8b8 b2b4 a5c4 d2c4
info depth 43 currmove a8b8 currmovenumber 1
info depth 43 currmove a5b3 currmovenumber 6
info depth 43 currmove f6e4 currmovenumber 7
info depth 43 currmove f6g4 currmovenumber 9
info depth 43 currmove e6e5 currmovenumber 10
info depth 43 currmove f8e8 currmovenumber 11
info depth 43 currmove d8d7 currmovenumber 15
info depth 43 currmove f6e8 currmovenumber 16
info depth 43 seldepth 72 score cp -26 upperbound nodes 201570022668 nps 8061733 time 25003310 multipv 1 pv a8b8 b2b4 a5c4 d2c4 f6d5 c3d5 g7a1 c1h6 a1g7
info depth 43 currmove a8b8 currmovenumber 1
info depth 43 currmove f6g4 currmovenumber 8
info depth 43 currmove f8e8 currmovenumber 10
info depth 43 seldepth 72 score cp -16 nodes 205948089631 nps 8063610 time 25540431 multipv 1 pv a8b8 b2b4 a5c4 d2c4 f6d5 c3d5 g7a1 c1h6 a1g7 h6g7 g8g7 d5f4 c8d7 d1d2 d7b5 c4a5 c7c6 f1c1 d6d5 a5b3 e6e5 f4d3 b5d3 d2d3 f7f5 b3c5 d8d6 e2e3 f8f7 d3e2 d6f6 a3a4 b8e8 a4a5 e5e4 e2d2 g6g5
info depth 44 currmove a8b8 currmovenumber 1
info depth 44 currmove d8d7 currmovenumber 6
info depth 44 currmove d8e8 currmovenumber 7
info depth 44 currmove b7b6 currmovenumber 13
info depth 44 currmove g7h8 currmovenumber 19
info depth 44 currmove h7h5 currmovenumber 20
info depth 44 currmove f6e8 currmovenumber 21
info depth 44 seldepth 72 score cp -16 nodes 214620973610 nps 8067330 time 26603717 multipv 1 pv a8b8 b2b4 a5c4 d2c4 f6d5 c3d5 g7a1 c1h6 a1g7 h6g7 g8g7 d5f4 c8d7 d1d2 d7b5 c4a5 c7c6 f1c1 d6d5 a5b3 f8e8 f4d3 b5c4 e2e3 c4b3 d2b2 e6e5 b2b3 d8f6 d3c5 e8e7 a3a4 e5e4 a4a5 b8a8 b3c2 a8e8 c2d2 e8d8 c1d1
User avatar
AdminX
Posts: 6340
Joined: Mon Mar 13, 2006 2:34 pm
Location: Acworth, GA

Re: Test position: beautiful positional sacrifice

Post by AdminX »

zullil wrote:
AdminX wrote:Here are the results I received from Stockfish Syzygy Dev at depth 33

Code: Select all


r1bq1rk1/1pp2pbp/p2ppnp1/n2P4/2P5/P1N3P1/1P1NPPBP/R1BQ1RK1 b - - 0 1

Analysis by Stockfish 200114 64:

1. +/=  (0.31): 10...exd5 11.cxd5 Nd7 12.Qc2 Ne5 13.b3 c5 14.Bb2 f5 15.e3 Bd7 16.Rab1 Rc8 17.Ne2 b5 18.Rfc1 Re8 19.Bc3 b4 20.Bxe5 dxe5 21.Qa2 e4 22.axb4 cxb4 23.Rxc8 Bxc8 24.Nc4 Nb7 25.Qxa6 Qxd5 26.Nb6 Qc6 27.Qa4 Qxa4 

2. +/=  (0.31): 10...Nd7 11.Qc2 Ne5 12.b3 exd5 13.cxd5 c5 14.Bb2 f5 15.e3 Bd7 16.Rab1 Rc8 17.Ne2 b5 18.Rfc1 Re8 19.Bc3 b4 20.Bxe5 dxe5 21.Qa2 e4 22.axb4 cxb4 23.Rxc8 Bxc8 24.Nc4 Nb7 25.Qxa6 Qxd5 26.Nb6 Qc6 27.Qa4 Qxa4 

3. +/=  (0.31): 10...Ng4 11.Qc2 Ne5 12.b3 exd5 13.cxd5 c5 14.Bb2 f5 15.e3 Bd7 16.Rab1 Rc8 17.Ne2 b5 18.Rfc1 Re8 19.Bc3 b4 20.Bxe5 dxe5 21.Qa2 e4 22.axb4 cxb4 23.Rxc8 Bxc8 24.Nc4 Nb7 25.Qxa6 Qxd5 26.Nb6 Qc6 27.Qa4 Qxa4 

Stockfish (8 threads, 4 GB hash, MultiPV=1) finally switches at depth 41:

Code: Select all

info depth 41 seldepth 65 score cp -23 nodes 156970800266 nps 8009674 time 19597650 multipv 1 pv a8b8 b2b4 a5c4 d2c4 f6d5 c3d5 g7a1 c1h6 a1g7 h6g7 g8g7 d5f4 h7h5 e2e4 c8d7 d1a1 e6e5 f4d5 d7b5 a1c3 h5h4 f1c1 b5c4 c3c4 c7c6 d5e3 f8h8 c1d1 d8f6 c4c3 b8c8 e3c4 c8d8 c3d2 c6c5 c4b6 f6e6 b6d5 d8c8 g2f3 h4g3
info depth 42 currmove a8b8 currmovenumber 1
info depth 42 seldepth 65 score cp -15 lowerbound nodes 161870524717 nps 8012539 time 20202149 multipv 1 pv a8b8 b2b4
info depth 42 currmove a8b8 currmovenumber 1
info depth 42 currmove a5b3 currmovenumber 6
info depth 42 currmove f6g4 currmovenumber 7
info depth 42 seldepth 65 score cp -31 upperbound nodes 174653338316 nps 8023045 time 21768958 multipv 1 pv a8b8 b2b4 f6d5 c4d5 g7c3 a1a2 c3d2 c1d2 a5c4 d2h6 b7b5 h6f8 d8f8 e2e4 e6d5 e4d5 c8d7 d1d4
info depth 42 currmove a8b8 currmovenumber 1
info depth 42 currmove e6e5 currmovenumber 9
info depth 42 currmove d8e7 currmovenumber 10
info depth 42 currmove d8d7 currmovenumber 16
info depth 42 currmove g7h6 currmovenumber 17
info depth 42 currmove h7h5 currmovenumber 18
info depth 42 currmove c7c5 currmovenumber 19
info depth 42 currmove f6e8 currmovenumber 20
info depth 42 currmove a8a7 currmovenumber 21
info depth 42 currmove a5c6 currmovenumber 22
info depth 42 currmove g6g5 currmovenumber 23
info depth 42 currmove c8d7 currmovenumber 24
info depth 42 currmove g8h8 currmovenumber 25
info depth 42 currmove g7h8 currmovenumber 26
info depth 42 currmove f6d5 currmovenumber 27
info depth 42 currmove a5c4 currmovenumber 28
info depth 42 seldepth 72 score cp -18 nodes 187373293586 nps 8052744 time 23268253 multipv 1 pv a8b8 b2b4 a5c4 d2c4 f6d5 c3d5 g7a1 c1h6 a1g7 h6g7 g8g7 d5f4 c8d7 d1d2 d7b5 c4a5 c7c6 f1c1 d6d5 f4d3 b5d3 d2d3 d8f6 d3d2 e6e5 a5b3 f8e8 b3c5 e8e7 g2h3 b8e8 e2e3 e5e4 a3a4 e8d8 a4a5 f6e5 c1d1 e5f6 h3g2
info depth 43 currmove a8b8 currmovenumber 1
info depth 43 seldepth 72 score cp -10 lowerbound nodes 195463482707 nps 8059396 time 24252867 multipv 1 pv a8b8 b2b4 a5c4 d2c4
info depth 43 currmove a8b8 currmovenumber 1
info depth 43 currmove a5b3 currmovenumber 6
info depth 43 currmove f6e4 currmovenumber 7
info depth 43 currmove f6g4 currmovenumber 9
info depth 43 currmove e6e5 currmovenumber 10
info depth 43 currmove f8e8 currmovenumber 11
info depth 43 currmove d8d7 currmovenumber 15
info depth 43 currmove f6e8 currmovenumber 16
info depth 43 seldepth 72 score cp -26 upperbound nodes 201570022668 nps 8061733 time 25003310 multipv 1 pv a8b8 b2b4 a5c4 d2c4 f6d5 c3d5 g7a1 c1h6 a1g7
info depth 43 currmove a8b8 currmovenumber 1
info depth 43 currmove f6g4 currmovenumber 8
info depth 43 currmove f8e8 currmovenumber 10
info depth 43 seldepth 72 score cp -16 nodes 205948089631 nps 8063610 time 25540431 multipv 1 pv a8b8 b2b4 a5c4 d2c4 f6d5 c3d5 g7a1 c1h6 a1g7 h6g7 g8g7 d5f4 c8d7 d1d2 d7b5 c4a5 c7c6 f1c1 d6d5 a5b3 e6e5 f4d3 b5d3 d2d3 f7f5 b3c5 d8d6 e2e3 f8f7 d3e2 d6f6 a3a4 b8e8 a4a5 e5e4 e2d2 g6g5
info depth 44 currmove a8b8 currmovenumber 1
info depth 44 currmove d8d7 currmovenumber 6
info depth 44 currmove d8e8 currmovenumber 7
info depth 44 currmove b7b6 currmovenumber 13
info depth 44 currmove g7h8 currmovenumber 19
info depth 44 currmove h7h5 currmovenumber 20
info depth 44 currmove f6e8 currmovenumber 21
info depth 44 seldepth 72 score cp -16 nodes 214620973610 nps 8067330 time 26603717 multipv 1 pv a8b8 b2b4 a5c4 d2c4 f6d5 c3d5 g7a1 c1h6 a1g7 h6g7 g8g7 d5f4 c8d7 d1d2 d7b5 c4a5 c7c6 f1c1 d6d5 a5b3 f8e8 f4d3 b5c4 e2e3 c4b3 d2b2 e6e5 b2b3 d8f6 d3c5 e8e7 a3a4 e5e4 a4a5 b8a8 b3c2 a8e8 c2d2 e8d8 c1d1
Wow! :lol:
"Good decisions come from experience, and experience comes from bad decisions."
__________________________________________________________________
Ted Summers
User avatar
velmarin
Posts: 1600
Joined: Mon Feb 21, 2011 9:48 am

Re: Test position: beautiful positional sacrifice

Post by velmarin »

Sure is so decisive ... ?
Complete game.

[pgn]
[Event "Wch U20 51st"]
[Site "Athens"]
[Date "2012.08.07"]
[Round "6"]
[White "Grandelius, Nils"]
[Black "Ipatov, Alexander"]
[Result "0-1"]
[ECO "E62"]
[WhiteElo "2562"]
[BlackElo "2577"]
[PlyCount "84"]
[EventDate "2012.08.02"]
[EventType "swiss"]
[EventRounds "13"]
[EventCountry "GRE"]
[Source "ChessBase"]
[SourceDate "2012.08.24"]

1. d4 Nf6 2. c4 e6 3. Nf3 Nc6 4. a3 d6 5. Nc3 g6 6. g3 Bg7 7. Bg2 O-O 8. O-O a6
9. d5 Na5 10. Nd2 Rb8 11. b4 Nxc4 12. Nxc4 Nxd5 13. Nxd5 Bxa1 14. Bh6 Bg7 15.
Bxg7 Kxg7 16. Qd4+ f6 17. Nc3 d5 18. Na5 c5 19. Qf4 Bd7 20. Rd1 b6 21. Nb3 c4
22. Nd2 e5 23. Qf3 d4 24. Nd5 Rc8 25. e4 c3 26. Nf1 Bb5 27. h4 f5 28. Rc1 Bc4
29. h5 b5 30. hxg6 hxg6 31. g4 Qg5 32. Qg3 Rfe8 33. gxf5 Qxg3 34. f6+ Kf8 35.
fxg3 Bxd5 36. exd5 e4 37. d6 Rcd8 38. g4 e3 39. g5 e2 40. Kf2 d3 41. Ne3 Rxe3
42. Rh1 e1=Q+ 0-1
[/pgn]
zullil
Posts: 6442
Joined: Tue Jan 09, 2007 12:31 am
Location: PA USA
Full name: Louis Zulli

Re: Test position: beautiful positional sacrifice

Post by zullil »

velmarin wrote:Sure is so decisive ... ?
Stockfish thinks that Black remains behind after Rb8. Hard to believe that this move is "decisive", but it might be best.
ernest
Posts: 2041
Joined: Wed Mar 08, 2006 8:30 pm

Re: Test position: beautiful positional sacrifice

Post by ernest »

maac wrote:Houdini 4 finds it at depth 24 (& 26).
My Houdini 4 does not find it!
You probably had some SMP luck... 8-)
ernest
Posts: 2041
Joined: Wed Mar 08, 2006 8:30 pm

Re: Test position: beautiful positional sacrifice

Post by ernest »

Well, with MPV=4, I did get it at depth 27:

Code: Select all

Analysis by Houdini 4 w32 Syz:

1. =  (0.15): 1...Rb8 2.b4 Nxc4 3.Nxc4 Nxd5 4.Nxd5 Bxa1 5.Nf4 Bg7 6.Na5 e5 7.Nd3 h5 8.h4 c6 9.Bg5 Qc7 10.Qd2 Be6 11.Rd1 f6 12.Be3 Kh7 13.Rc1 Rfd8 14.a4 d5 15.Nc5 Bf5 16.Qa2 Bf8 17.Qb3 
2. +/=  (0.27): 1...Nd7 2.Qc2 Ne5 3.b3 c6 4.dxc6 Naxc6 5.Rd1 f5 6.e3 Bd7 7.Bb2 Rc8 8.Ne2 Qc7 9.h3 Rfe8 10.Kh2 b5 11.f4 Nf7 12.Bxg7 Kxg7 13.Qc3+ e5 14.Rac1 Ne7 15.fxe5 dxe5 16.Nf4 Kg8 17.Nd5 Nxd5 18.Bxd5 Be6 19.Nf3 Bxd5 
3. +/=  (0.28): 1...Ng4 2.Qc2 exd5 3.cxd5 Ne5 4.b3 c5 5.Bb2 f5 6.e3 Bd7 7.Ne2 Rc8 8.a4 b6 9.Bc3 Re8 10.Rfc1 Qe7 11.Rab1 Qf7 12.b4 cxb4 13.Rxb4 b5 14.Nd4 Rc5 15.axb5 Rec8 16.bxa6 Rxc3 17.Qxc3 Rxc3 18.Rxc3 Be8 19.Rb6 
4. +/=  (0.28): 1...exd5 2.cxd5 Ng4 3.Qc2 Ne5 4.b3 c5 5.Bb2 f5 6.e3 Bd7 7.Ne2 Rc8 8.a4 b6 9.Bc3 Re8 10.Rfc1 Qe7 11.Rab1 Qf7 12.b4 cxb4 13.Rxb4 b5 14.Nd4 Rc5 15.axb5 Rec8 16.bxa6 Rxc3 17.Qxc3 Rxc3 18.Rxc3 Be8 19.Rb6