1.e4 c6 2.Nf3 d5 3.exd5 cxd5 4.Bb5+ Bd7 5.Bxd7+ Nxd7 6.OO e6 7.b3 Ngf6 8.Bb2 Bd6 9.Qe2 Qc7 10.c4 dxc4 11.Qxc4 Qxc4 12.bxc4 Rc8
13.Na3 a6 14.Rab1 OO 15.d3 b6 16.Rfc1 Nh5 17.g3 Nc5 18.Rd1 Na4 19.Nc2 Nxb2 20.Rxb2 Bc7 21.Nb4 Ra8 22.Nc6 Nf6 23.a4 Rfe8 24.Nfe5
Rac8 25.Rdb1 h5 26.f4 Ng4 27.Nxg4 hxg4 28.Kf2 f6 29.Rxb6?!
[d]2r1r1k1/2b3p1/pRN1pp2/8/P1P2Pp1/3P2P1/5K1P/1R6 b   0 29
Bxb6+ 30.Rxb6 a5 31.Ke3 e5 32.fxe5 Re6 33.Na7 Rxe5+ 34.Kf4 Ra8 35.Nb5
Rh5 36.d4 Rxh2 37.c5 Rf2+ 38.Ke4 f5+ 39.Kd5 f4 40.gxf4 Rxf4 41.Re6 Rf5+ 42.Kc4 Rg5 43.Re2 g3 44.Rg2 Kf7 45.c6 Ke7 46.d5 Rf8
47.Re2+ Kd8 48.c7+ Kd7 49.d6 Kc6 50.Re7 Rg4+ 51.Kd3 g2 52.d7 Rg3+ 53.Ke4 Rg4+ 54.Kd3 Rg3+ 55.Ke4 Rg4+ 56.Kd3 1/21/2
can Black win this game after 29. Rxb6?! ...
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 Posts: 405
 Joined: Sat Jul 02, 2011 8:49 pm
Re: can Black win this game after 29. Rxb6?! ...
Not sure about the question after 29th white move, but I guess White has to struggle hard. Black at least has better chances to win but White has to draw.pilgrimdan wrote: ↑Mon Aug 12, 2019 2:44 am1.e4 c6 2.Nf3 d5 3.exd5 cxd5 4.Bb5+ Bd7 5.Bxd7+ Nxd7 6.OO e6 7.b3 Ngf6 8.Bb2 Bd6 9.Qe2 Qc7 10.c4 dxc4 11.Qxc4 Qxc4 12.bxc4 Rc8
13.Na3 a6 14.Rab1 OO 15.d3 b6 16.Rfc1 Nh5 17.g3 Nc5 18.Rd1 Na4 19.Nc2 Nxb2 20.Rxb2 Bc7 21.Nb4 Ra8 22.Nc6 Nf6 23.a4 Rfe8 24.Nfe5
Rac8 25.Rdb1 h5 26.f4 Ng4 27.Nxg4 hxg4 28.Kf2 f6 29.Rxb6?!
[d]2r1r1k1/2b3p1/pRN1pp2/8/P1P2Pp1/3P2P1/5K1P/1R6 b   0 29
Bxb6+ 30.Rxb6 a5 31.Ke3 e5 32.fxe5 Re6 33.Na7 Rxe5+ 34.Kf4 Ra8 35.Nb5
Rh5 36.d4 Rxh2 37.c5 Rf2+ 38.Ke4 f5+ 39.Kd5 f4 40.gxf4 Rxf4 41.Re6 Rf5+ 42.Kc4 Rg5 43.Re2 g3 44.Rg2 Kf7 45.c6 Ke7 46.d5 Rf8
47.Re2+ Kd8 48.c7+ Kd7 49.d6 Kc6 50.Re7 Rg4+ 51.Kd3 g2 52.d7 Rg3+ 53.Ke4 Rg4+ 54.Kd3 Rg3+ 55.Ke4 Rg4+ 56.Kd3 1/21/2
Anyhow in the given continuation, there are some blunders from White as well as from Black.
Biggest one (game changing) is 34...Ra8 (?).
After Backward and 34...Rd8 instead:
Analysis by Cfish 050819 x64 POP N:
35.Nc6 Re6 36.Kf5 Rdd6 37.Ne7+ Kf7 38.Rxd6 Rxd6 39.Nd5 Re6 40.Kxg4 Re2 41.Kf3 Rxh2 42.Ke4 Re2+ 43.Kf4 Ra2 44.Nb6 g5+ 45.Ke4 Re2+ 46.Kf3 Rc2 47.Na8 Ke6 48.Nc7+ Kd6 49.Nd5 Ke5 50.Ke3 Rg2 51.d4+ Ke6 52.Nc7+ Kd7 53.Kf3 Ra2 54.Nd5 Ke6 55.Nb6 Ra3+ 56.Kg4 Kd6 57.Kf5 Rxg3 58.c5+ Kc6 59.Kxf6 g4 60.Kf5 Rc3 61.Kxg4 Rd3 62.Kg5 Rxd4
+ (5.32) Depth: 45/84 00:07:54 12863MN, tb=47781368
After 31.d4 instead of Ke3(?!) it's =, 34.Kf4(?) +, after 34.Kd2 instead again /+.
Output after 30...e5 instead of ...a5(?):
Analysis by Cfish 050819 x64 POP N:
31.a5 exf4 32.gxf4 Kh7 33.c5 f5 34.d4 Re4 35.d5 Rxf4+ 36.Kg2 Rf3 37.Rb8 Rc7 38.Nd4 Rxc5 39.Nxf3 gxf3+ 40.Kxf3 Rxd5 41.Rb6 Rxa5 42.Kf4 Ra2 43.Kxf5 a5 44.h3 Rf2+ 45.Kg4 Rf6 46.Rb5 Ra6 47.Rb3 a4 48.Ra3 Kg6 49.Kf4 Ra5 50.Kg4 Kf6 51.Kf3 Kf5 52.Kf2 Ke5 53.Ke2 Kf4 54.Kf1 Ke4 55.Ke1 Ra7 56.Ke2 Kf5 57.Ke3 Ke6 58.Ke2 Ra6 59.Ke1 Ra5 60.Ke2 g5 61.Kd2 Kd6 62.Kd3 Kd5 63.Kd2 Ke6 64.Ke3 Kf5 65.Kf2 Ra6 66.Ke2 Ke4 67.Ke1 Ke5 68.Ke2
+ (1.71) Depth: 50/74 00:06:57 9814MN, tb=33962291
Here's the .pgn with some alternative moves inserted from Cfish, evals shown with quoting.
Peter.
 Eelco de Groot
 Posts: 4243
 Joined: Sun Mar 12, 2006 1:40 am
 Location: Groningen
Re: can Black win this game after 29. Rxb6?! ...
Hi guys, I think Black wins it fairly easily from Dan's position on I did a simple shootout, only 30 plies fixed depth. Sometimes the extensions run away (this not a very good version for controlling depths) and a 40 ply deep search can go for 900 minutes, for just one move. Shootout begun at high noon lasts a week So I did only 30 plies but now it goes very quickly. Essentially by move 40 White should resign.
Endposition:
[D]8/8/p7/8/5k2/8/6q1/1K3r2 w  
Endposition:
[D]8/8/p7/8/5k2/8/6q1/1K3r2 w  
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
place. Therefore, if you write the code as cleverly as possible, you
are, by definition, not smart enough to debug it.
 Brian W. Kernighan
 Eelco de Groot
 Posts: 4243
 Joined: Sun Mar 12, 2006 1:40 am
 Location: Groningen
Re: can Black win this game after 29. Rxb6?! ...
Black still has a plus, but to me looks like White has reasonable chances to draw, in spite of score, after 30... e5 {instead of 30... a5?} 31. a5 exf4 32. gxf4 Kh7 33. f5 {=+} Kh6 34. Rxa6 Kg5 35. Nd4
Engine: Kaissa IV NoContempt (not the best version, one thread, no tablebases, 512 MB)
by T. Romstad, M. Costalba, J. Kiiski, G. Linscott
47 77:26 1.49 35...Re7 36.Rd6 Rb8 37.Re6 Rd7
38.Ke3 Rbd8 39.Re4 Rh8 40.c5 Rh3+
41.Kd2 Rxh2+ 42.Kc3 Ra7 43.c6 Rh8
44.Kb4 g3 45.Re2 Kg4 46.Nb5 Raa8
47.c7 Rh2 48.Re1 Rb2+ (8.792.083.230) 1892
47 77:26 1.31 35...Re5 36.Ra7 Kh6 37.Rd7 Ra8
38.Kg3 Re3+ 39.Kxg4 Rxd3 40.Rd5 Rc3
41.Rc5 Ra3 42.Kf4 R3xa5 43.Rxa5 Rxa5
44.Ke4 Re5+ 45.Kd3 g5 46.fxg6 Kxg6
47.h4 Rh5 48.Ke4 Rc5 (8.792.083.230) 1892
47 77:26 0.37 35...Rh8 36.Ne6+ Kxf5 37.Nxg7+ Kg6
38.Ne6 Rxh2+ 39.Kg3 Rh1 40.Rd6 Rg1+
41.Kf2 Rd1 42.c5 Kf5 43.Ng7+ Ke5
44.Re6+ Kd4 45.Rxf6 g3+ 46.Kg2 Kxc5
47.Rf3 Rd2+ 48.Kxg3 Rg8 (8.792.083.230) 1892
47 77:26 0.16 35...Kh4 36.Ne6 Ra8 37.Rxa8 Rxa8
38.d4 Kh3 39.d5 Kxh2 40.Ke3 g3
41.Nf4 Rxa5 42.d6 Re5+ 43.Kd3 Re1
44.Kc2 Re4 45.d7 Rd4 46.Nd5 g2
47.d8Q g1Q 48.Qh8+ Kg3 (8.792.083.230) 1892
47 77:26 0.13 35...Ra8 36.Rxa8 Rxa8 37.c5 Kh4
38.Ke3 Rxa5 39.Ne6 Ra2 40.d4 Rxh2
41.d5 g3 42.d6 Ra2 43.Nf4 Ra3+
44.Ke2 Kg4 45.d7 Ra8 46.Ke3 g2
47.Nxg2 Kxf5 48.Nf4 Ke5 (8.792.083.230) 1892
Engine: Kaissa IV NoContempt (not the best version, one thread, no tablebases, 512 MB)
by T. Romstad, M. Costalba, J. Kiiski, G. Linscott
47 77:26 1.49 35...Re7 36.Rd6 Rb8 37.Re6 Rd7
38.Ke3 Rbd8 39.Re4 Rh8 40.c5 Rh3+
41.Kd2 Rxh2+ 42.Kc3 Ra7 43.c6 Rh8
44.Kb4 g3 45.Re2 Kg4 46.Nb5 Raa8
47.c7 Rh2 48.Re1 Rb2+ (8.792.083.230) 1892
47 77:26 1.31 35...Re5 36.Ra7 Kh6 37.Rd7 Ra8
38.Kg3 Re3+ 39.Kxg4 Rxd3 40.Rd5 Rc3
41.Rc5 Ra3 42.Kf4 R3xa5 43.Rxa5 Rxa5
44.Ke4 Re5+ 45.Kd3 g5 46.fxg6 Kxg6
47.h4 Rh5 48.Ke4 Rc5 (8.792.083.230) 1892
47 77:26 0.37 35...Rh8 36.Ne6+ Kxf5 37.Nxg7+ Kg6
38.Ne6 Rxh2+ 39.Kg3 Rh1 40.Rd6 Rg1+
41.Kf2 Rd1 42.c5 Kf5 43.Ng7+ Ke5
44.Re6+ Kd4 45.Rxf6 g3+ 46.Kg2 Kxc5
47.Rf3 Rd2+ 48.Kxg3 Rg8 (8.792.083.230) 1892
47 77:26 0.16 35...Kh4 36.Ne6 Ra8 37.Rxa8 Rxa8
38.d4 Kh3 39.d5 Kxh2 40.Ke3 g3
41.Nf4 Rxa5 42.d6 Re5+ 43.Kd3 Re1
44.Kc2 Re4 45.d7 Rd4 46.Nd5 g2
47.d8Q g1Q 48.Qh8+ Kg3 (8.792.083.230) 1892
47 77:26 0.13 35...Ra8 36.Rxa8 Rxa8 37.c5 Kh4
38.Ke3 Rxa5 39.Ne6 Ra2 40.d4 Rxh2
41.d5 g3 42.d6 Ra2 43.Nf4 Ra3+
44.Ke2 Kg4 45.d7 Ra8 46.Ke3 g2
47.Nxg2 Kxf5 48.Nf4 Ke5 (8.792.083.230) 1892
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
place. Therefore, if you write the code as cleverly as possible, you
are, by definition, not smart enough to debug it.
 Brian W. Kernighan

 Posts: 405
 Joined: Sat Jul 02, 2011 8:49 pm
Re: can Black win this game after 29. Rxb6?! ...
thanks Peter … and every one else … appreciate the analysis …peter wrote: ↑Mon Aug 12, 2019 7:25 amNot sure about the question after 29th white move, but I guess White has to struggle hard. Black at least has better chances to win but White has to draw.pilgrimdan wrote: ↑Mon Aug 12, 2019 2:44 am1.e4 c6 2.Nf3 d5 3.exd5 cxd5 4.Bb5+ Bd7 5.Bxd7+ Nxd7 6.OO e6 7.b3 Ngf6 8.Bb2 Bd6 9.Qe2 Qc7 10.c4 dxc4 11.Qxc4 Qxc4 12.bxc4 Rc8
13.Na3 a6 14.Rab1 OO 15.d3 b6 16.Rfc1 Nh5 17.g3 Nc5 18.Rd1 Na4 19.Nc2 Nxb2 20.Rxb2 Bc7 21.Nb4 Ra8 22.Nc6 Nf6 23.a4 Rfe8 24.Nfe5
Rac8 25.Rdb1 h5 26.f4 Ng4 27.Nxg4 hxg4 28.Kf2 f6 29.Rxb6?!
[d]2r1r1k1/2b3p1/pRN1pp2/8/P1P2Pp1/3P2P1/5K1P/1R6 b   0 29
Bxb6+ 30.Rxb6 a5 31.Ke3 e5 32.fxe5 Re6 33.Na7 Rxe5+ 34.Kf4 Ra8 35.Nb5
Rh5 36.d4 Rxh2 37.c5 Rf2+ 38.Ke4 f5+ 39.Kd5 f4 40.gxf4 Rxf4 41.Re6 Rf5+ 42.Kc4 Rg5 43.Re2 g3 44.Rg2 Kf7 45.c6 Ke7 46.d5 Rf8
47.Re2+ Kd8 48.c7+ Kd7 49.d6 Kc6 50.Re7 Rg4+ 51.Kd3 g2 52.d7 Rg3+ 53.Ke4 Rg4+ 54.Kd3 Rg3+ 55.Ke4 Rg4+ 56.Kd3 1/21/2
Anyhow in the given continuation, there are some blunders from White as well as from Black.
Biggest one (game changing) is 34...Ra8 (?).
After Backward and 34...Rd8 instead:
Analysis by Cfish 050819 x64 POP N:
35.Nc6 Re6 36.Kf5 Rdd6 37.Ne7+ Kf7 38.Rxd6 Rxd6 39.Nd5 Re6 40.Kxg4 Re2 41.Kf3 Rxh2 42.Ke4 Re2+ 43.Kf4 Ra2 44.Nb6 g5+ 45.Ke4 Re2+ 46.Kf3 Rc2 47.Na8 Ke6 48.Nc7+ Kd6 49.Nd5 Ke5 50.Ke3 Rg2 51.d4+ Ke6 52.Nc7+ Kd7 53.Kf3 Ra2 54.Nd5 Ke6 55.Nb6 Ra3+ 56.Kg4 Kd6 57.Kf5 Rxg3 58.c5+ Kc6 59.Kxf6 g4 60.Kf5 Rc3 61.Kxg4 Rd3 62.Kg5 Rxd4
+ (5.32) Depth: 45/84 00:07:54 12863MN, tb=47781368
After 31.d4 instead of Ke3(?!) it's =, 34.Kf4(?) +, after 34.Kd2 instead again /+.
Output after 30...e5 instead of ...a5(?):
Analysis by Cfish 050819 x64 POP N:
31.a5 exf4 32.gxf4 Kh7 33.c5 f5 34.d4 Re4 35.d5 Rxf4+ 36.Kg2 Rf3 37.Rb8 Rc7 38.Nd4 Rxc5 39.Nxf3 gxf3+ 40.Kxf3 Rxd5 41.Rb6 Rxa5 42.Kf4 Ra2 43.Kxf5 a5 44.h3 Rf2+ 45.Kg4 Rf6 46.Rb5 Ra6 47.Rb3 a4 48.Ra3 Kg6 49.Kf4 Ra5 50.Kg4 Kf6 51.Kf3 Kf5 52.Kf2 Ke5 53.Ke2 Kf4 54.Kf1 Ke4 55.Ke1 Ra7 56.Ke2 Kf5 57.Ke3 Ke6 58.Ke2 Ra6 59.Ke1 Ra5 60.Ke2 g5 61.Kd2 Kd6 62.Kd3 Kd5 63.Kd2 Ke6 64.Ke3 Kf5 65.Kf2 Ra6 66.Ke2 Ke4 67.Ke1 Ke5 68.Ke2
+ (1.71) Depth: 50/74 00:06:57 9814MN, tb=33962291
Here's the .pgn with some alternative moves inserted from Cfish, evals shown with quoting.
Re: can Black win this game after 29. Rxb6?! ...
Black can't win. It's still one of those positions that are drawn with perfect play.
Your beliefs create your reality, so be careful what you wish for.

 Posts: 405
 Joined: Sat Jul 02, 2011 8:49 pm