Removal of the guard -- a very hard problem.

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Dann Corbit
Posts: 12540
Joined: Wed Mar 08, 2006 8:57 pm
Location: Redmond, WA USA

Removal of the guard -- a very hard problem.

Post by Dann Corbit »

How long does it take your favorite engine to solve it?
[d]rnbqnrk1/ppp1ppbp/3p2p1/4P3/2PP1P2/2N1B3/PP4PP/R2QKBNR b KQ - bm c5; C0 "Leipzig/Fischer 1960";

Code: Select all

Analysis from C:\tmp\LF1960.EPD   
12/6/2008 1:33:37 AM Level: 200000 Seconds
Analyzing engine: Rybka 3

1) c5; C0 "Leipzig/Fisc 
    Searching move: c7-c5
    Best move (Rybka 3): c7-c5
    identical moves! Found in: 38:28
      2	00:00	         460	14.720	-0.19	Nb8c6
      2	00:00	         822	17.909	+0.01	c7c6
      3	00:00	       1.646	35.861	-0.08	c7c6
      4	00:00	       2.514	54.773	-0.10	c7c6
      4	00:00	       3.043	49.460	-0.06	Bc8f5
      5	00:00	       7.564	98.044	-0.06	Bc8f5 g2g4
      6	00:00	      12.479	102.227	-0.07	Bc8f5 g2g4 Bf5d7
      7	00:00	      24.396	123.061	-0.16	Bc8f5 Ng1f3 Nb8c6 Qd1b3
      8	00:00	      36.160	124.672	-0.17	Bc8f5 Ng1f3 Nb8c6 Qd1b3 a7a5
      9	00:00	      90.213	144.340	-0.19	Bc8f5 Qd1b3 b7b6 000 c7c5 Ng1f3 Nb8a6
      9	00:00	     105.966	144.872	-0.10	Nb8c6 Ng1f3 Bc8f5 Qd1b3 a7a5 a2a3
     10	00:01	     121.277	144.572	-0.15	Nb8c6 Ng1f3 Bc8f5 Qd1b3 a7a5 a2a3 a5a4
     11	00:01	     192.697	143.715	-0.20	Nb8c6 Ng1f3 Bc8f5 Qd1b3 a7a5 Ke1f2 Nc6b4 Ra1c1
     11	00:03	     584.844	164.031	-0.01	f7f6 Qd1b3 f6xe5 d4xe5 d6xe5 Ra1d1 Nb8d7
     12	00:05	     802.482	166.142	-0.15	f7f6 Qd1b3 f6xe5 d4xe5 d6xe5 f4xe5 c7c5 Ng1f3 Nb8c6 Be3xc5 Qd8c7 Bc5e3 Nc6xe5 Nc3d5
     13	00:09	   1.481.158	170.263	-0.05	f7f6 Qd1b3 f6xe5 d4xe5 Bg7h6 e5xd6 e7xd6 000 Bh6xf4 Be3xf4 Rf8xf4 c4c5+ Kg8g7
     14	00:16	   2.641.549	169.493	-0.17	f7f6 Qd1b3 f6xe5 f4xe5 d6xe5 d4xe5 c7c5 Ng1f3 Nb8c6 Be3xc5 Qd8c7 Bc5e3 Nc6xe5 000 Ne5xf3 Nc3d5
     14	00:23	   3.922.941	172.126	-0.13	Nb8c6 Qd1b3 Bg7h6 000 Ne8g7 Bf1d3 Ra8b8 Ng1e2 Bc8f5 Bd3b1 Qd8d7
     15	00:29	   4.869.192	172.671	-0.11	Nb8c6 Qd1b3 Bg7h6 000 Ne8g7 Bf1d3 a7a5 Ng1e2 a5a4 Nc3xa4 Ng7f5 Bd3xf5 Bc8xf5 Na4c3 Qd8c8 Nc3d5
     16	00:38	   6.338.052	171.488	-0.11	Nb8c6 Qd1b3 Bg7h6 000 Ne8g7 Bf1d3 a7a5 Ng1e2 a5a4 Nc3xa4 Ng7f5 Bd3xf5 Bc8xf5 Na4c3 Nc6a5 Qb3b5 c7c6
     17	01:28	  14.524.339	169.248	-0.21	Nb8c6 Ng1f3 d6xe5 f4xe5 f7f6 e5e6
     17	03:52	  38.183.084	168.381	-0.09	d6xe5 d4xe5 Qd8xd1+ Ra1xd1 f7f6 e5xf6 Ne8xf6 Ng1f3 Nb8c6 Bf1e2 Bc8f5 h2h3 Nf6e4 Nc3xe4 Bf5xe4 Nf3g5 Be4f5 g2g4 h7h6 g4xf5 h6xg5 f4xg5 Rf8xf5 Rd1d2 Rf5e5 Be3f4 Re5e4 00 Bg7e5
     18	04:10	  41.989.556	171.908	-0.09	d6xe5 d4xe5 Qd8xd1+ Ra1xd1 f7f6 e5xf6 Ne8xf6 Ng1f3 Nb8c6 Bf1e2 Bc8f5 h2h3 Nf6e4 Nc3xe4 Bf5xe4 Nf3g5 Be4f5 g2g4 h7h6 g4xf5 h6xg5 f4xg5 Rf8xf5 Rd1d2 Rf5e5 Be3f4 Re5e4 00 Bg7e5
     19	05:19	  54.349.114	174.049	-0.09	d6xe5 d4xe5 Qd8xd1+ Ra1xd1 f7f6 e5xf6 Ne8xf6 Ng1f3 Nb8c6 Bf1e2 Bc8f5 h2h3 Nf6e4 Nc3xe4 Bf5xe4 Nf3g5 Be4f5 g2g4 h7h6 g4xf5 h6xg5 f4xg5 Rf8xf5 Rd1d2 Rf5e5 Be3f4 Re5e4 00 Bg7e5
     20	07:37	  78.519.493	175.756	-0.09	d6xe5 d4xe5 Qd8xd1+ Ra1xd1 f7f6 e5xf6 Ne8xf6 Ng1f3 Nb8c6 Bf1e2 Bc8f5 h2h3 Nf6e4 Nc3xe4 Bf5xe4 Nf3g5 Be4f5 g2g4 h7h6 g4xf5 h6xg5 f4xg5 Rf8xf5 Rd1d2 Rf5e5 Be3f4 Re5e4 00 Bg7e5
     21	17:05	 191.230.728	191.075	-0.17	d6xe5 d4xe5 Qd8xd1+ Ra1xd1 f7f6 e5xf6 Ne8xf6 Ng1f3 Nb8a6 Bf1e2 Nf6g4
     21	38:28	 435.299.810	193.094	-0.12	c7c5 d4xc5 Nb8c6
     22	1:06:59	 811.906.989	206.829	-0.11	c7c5 d4xc5 Nb8c6 c5xd6 e7xd6 Ng1f3 Bc8e6 Bf1e2 Qd8a5 Qd1a4 Qa5xa4 Nc3xa4 d6xe5 Be3c5 e5xf4 00 Ne8c7 Bc5xf8 Ra8xf8 Ra1d1 Rf8e8 Rd1d2 Nc7a6 Rf1d1 Be6f5 a2a3
     23	1:28:06	1.035.961.278	200.673	-0.11	c7c5 d4xc5 Nb8c6 c5xd6 e7xd6 Ng1f3 Bc8e6 Bf1e2 Qd8a5 Qd1a4 Qa5xa4 Nc3xa4 d6xe5 Be3c5 e5xf4 00 Ne8c7 Bc5xf8 Ra8xf8 Ra1d1 Rf8e8 Rd1d2 Nc7a6 Rf1d1 Be6f5 a2a3
     24	2:42:36	1.908.237.580	200.283	-0.14	c7c5 d4xc5 Nb8c6 c5xd6 e7xd6 Ng1f3 Bc8e6 Bf1e2 Qd8a5 Qd1a4 Qa5xa4 Nc3xa4 d6xe5 Be3c5 e5xf4 00 Ne8c7 Bc5xf8 Ra8xf8 Ra1d1 Rf8e8 Rd1d2 Nc7a6 Rf1d1 Be6f5 a2a3
     25	6:09:33	4.389.308,608	202.710	-0.14	c7c5 d4xc5 Nb8c6 c5xd6 e7xd6 Ng1f3 Bc8e6 Bf1e2 Qd8a5 Qd1a4 Qa5xa4 Nc3xa4 d6xe5 Be3c5 e5xf4 00 Be6f5 Na4c3 Ne8f6 Bc5xf8 Kg8xf8 Ra1d1 Nf6g4 Rd1d2 Bg7xc3 b2xc3 Ng4e3 Rf1e1 Ra8e8 c4c5 Nc6e5
     26	10:39:46	7.592.174,444	202.533	-0.14	c7c5 d4xc5 Nb8c6 c5xd6 e7xd6 Ng1f3 Bc8e6 Bf1e2 Qd8a5 Qd1a4 Qa5xa4 Nc3xa4 d6xe5 Be3c5 e5xf4 00 Be6f5 Na4c3 Ne8f6 Bc5xf8 Kg8xf8 Ra1d1 Nf6g4 Rd1d2 Bg7xc3 b2xc3 Ng4e3 Rf1e1 Ra8e8 c4c5 Nc6e5
     27	22:12:21	15.862.805,415	203.196	-0.14	c7c5 d4xc5 Nb8c6 c5xd6 e7xd6 Ng1f3 Bc8e6 Bf1e2 Qd8a5 Qd1a4 Qa5xa4 Nc3xa4 d6xe5 Be3c5 e5xf4 00 Be6f5 Na4c3 Ne8f6 Bc5xf8 Kg8xf8 Ra1d1 Nf6g4 Rd1d2 Bg7xc3 b2xc3 Ng4e3 Rf1e1 Ra8e8 c4c5 Nc6e5
   12/8/2008 9:07:06 AM, Time for this analysis: 07:33:23, Rated time: 38:28

1 of 1 matching moves
12/8/2008 9:07:07 AM, Total time: 7:33:29 AM
Rated time: 38:28 = 2308 Seconds
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Dann Corbit
Posts: 12540
Joined: Wed Mar 08, 2006 8:57 pm
Location: Redmond, WA USA

Re: Removal of the guard -- a very hard problem.

Post by Dann Corbit »

This is the game from which the position was extracted:

[Event "14. olm qual. group 4"]
[Site "Leipzig GDR"]
[Date "1960.10.24"]
[Round "8"]
[White "Letelier Martner, Rene CHI"]
[Black "Fischer, Robert James USA"]
[Result "0-1"]
[ECO "E70c"]
[Variation "King's Indian: 4.e4 O-O 5.e5"]

1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 O-O 5.e5 Ne8 6.f4 d6 7.Be3 c5 8.dxc5 Nc6
9.cxd6 exd6 10.Ne4 Bf5 11.Ng3 Be6 12.Nf3 Qc7 13.Qb1 dxe5 14.f5 e4 15.fxe6
exf3 16.gxf3 f5 17.f4 Nf6 18.Be2 Rfe8 19.Kf2 Rxe6 20.Re1 Rae8 21.Bf3 Rxe3
22.Rxe3 Rxe3 23.Kxe3 Qxf4+ 24.Kxf4 Bh6# 0-1
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kiroje

Re: Removal of the guard -- a very hard problem.

Post by kiroje »

Dann Corbit wrote:This is the game from which the position was extracted:

[Event "14. olm qual. group 4"]
[Site "Leipzig GDR"]
[Date "1960.10.24"]
[Round "8"]
[White "Letelier Martner, Rene CHI"]
[Black "Fischer, Robert James USA"]
[Result "0-1"]
[ECO "E70c"]
[Variation "King's Indian: 4.e4 O-O 5.e5"]

1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 O-O 5.e5 Ne8 6.f4 d6 7.Be3 c5 8.dxc5 Nc6
9.cxd6 exd6 10.Ne4 Bf5 11.Ng3 Be6 12.Nf3 Qc7 13.Qb1 dxe5 14.f5 e4 15.fxe6
exf3 16.gxf3 f5 17.f4 Nf6 18.Be2 Rfe8 19.Kf2 Rxe6 20.Re1 Rae8 21.Bf3 Rxe3
22.Rxe3 Rxe3 23.Kxe3 Qxf4+ 24.Kxf4 Bh6# 0-1
On a sidenote, its game 21 in Fischers excellent "My 60 memorable games" book - highly recommended reading.
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kgburcham
Posts: 2016
Joined: Sun Feb 17, 2008 4:19 pm

Re: Removal of the guard -- a very hard problem.

Post by kgburcham »

Dan I let Rybka 3 run this position in the Chessbase interface and it did not list c5. In the Shredder interface Rybka 3 will choose c5 but then leaves it. Not much difference in eval before or after. At depth 22 eval is falling so maybe it would play c5 at greater depth. Maybe fischer would win with f6, c5, dxe5, or maybe another. I do not doubt that c5 is a good move but Rybka score stays -.5 until move 15.fxe6, after that white plays several moves with score increasing for black with each move. It seems to me the better player that day won the game by making less mistakes after move 15.

In the end the biggest loser was fischer, sad.
kgburcham

[D] rnbqnrk1/ppp1ppbp/3p2p1/4P3/2PP1P2/2N1B3/PP4PP/R2QKBNR b KQ -

Rybka 3 (shredder)

13.14 0:15 +0.13 7...f6 8.exd6 Nxd6 9.Qd2 Nc6 10.O-O-O Na5 11.b3 c6 (2.053.989) 134
14.01 0:20 +0.15 7...f6 8.exd6 Nxd6 9.Qd2 Nc6 10.O-O-O e5 11.dxe5 fxe5 12.c5 Nf7 13.Qf2 Qe8 14.Nd5 (2.640.774) 135
15.01 0:31 +0.20 7...f6 8.exd6 Nxd6 9.Nf3 Nc6 10.d5 Na5 11.Qa4 c6 12.O-O-O cxd5 13.c5 Nf5 14.Rxd5 (4.055.193) 131
15.04 0:48 +0.19 7...dxe5 8.dxe5 Qxd1+ 9.Rxd1 Nc6 10.Nd5 e6 11.Nc3 f6 (6.366.636) 133
16.01 0:59 +0.15 7...dxe5 8.dxe5 Qxd1+ 9.Rxd1 Nc6 10.Nf3 f6 11.exf6 Bxf6 12.Be2 Bxc3+ 13.bxc3 Nd6 14.c5 (8.021.257) 138
17.01 1:26 +0.18 7...dxe5 8.dxe5 Qxd1+ 9.Rxd1 Nc6 10.Nf3 f6 11.exf6 Bxf6 12.Be2 Nd6 13.Nb5 Ne8 14.Nbd4 Nxd4 15.Bxd4 Ng7 16.Bxf6 exf6 17.O-O Nf5 18.Rfe1 Ne3 (12.069.464) 142
18.01 2:34 +0.15 7...dxe5 8.dxe5 Qxd1+ 9.Rxd1 Nc6 10.Nf3 f6 11.exf6 Bxf6 12.Be2 Nd6 13.O-O Bxc3 14.bxc3 Be6 15.Nd2 Na5 16.c5 Ndc4 17.Bd4 Rad8 18.Bxc4 Bxc4 19.Rfe1 Rd7 20.Nxc4 (22.059.206) 146
19.01 4:09 +0.09 7...dxe5 8.dxe5 Qxd1+ 9.Rxd1 Nc6 10.Nf3 f6 11.exf6 Bxf6 12.Be2 Nd6 13.O-O Be6 14.c5 Nf5 15.Bf2 Ng7 16.g3 Rad8 17.a3 Bb3 18.Rd2 Nf5 19.Rxd8 Rxd8 20.Nb5 Rd7 (36.110.179) 148
20.01 7:56 +0.15 7...dxe5 8.dxe5 Qxd1+ 9.Rxd1 Nc6 10.Nf3 f6 11.exf6 Bxf6 12.Be2 Nd6 13.O-O Be6 14.c5 Nf5 15.Bf2 Rad8 16.Ng5 Bxg5 17.fxg5 Nfd4 (71.775.095) 154
20.12 19:14 +0.08 7...c5 8.dxc5 Nc6 (183.004.854) 162
21.01 39:11 +0.16 7...c5 8.dxc5 Nc6 9.cxd6 exd6 10.Nf3 Be6 11.Be2 Qa5 12.Qa4 Qxa4 13.Nxa4 dxe5 14.Bc5 exf4 15.O-O Bf5 16.Nc3 Nf6 17.Bxf8 Rxf8 18.Rad1 Ng4 19.Rd2 Bxc3 20.bxc3 Ne3 (403.825.612) 175
21.02 51:52 +0.15 7...dxe5 8.dxe5 Qxd1+ 9.Rxd1 Nc6 10.Nf3 f6 11.exf6 Bxf6 12.Be2 Nd6 13.O-O Be6 14.c5 Nf5 15.Bf2 Rad8 16.Ng5 Bxg5 17.fxg5 Nfd4 (539.896.194) 177
22.01 58:22 +0.14 7...dxe5 8.dxe5 Qxd1+ 9.Rxd1 Nc6 10.Nf3 f6 11.exf6 Bxf6 12.Be2 Nd6 13.O-O Be6 14.c5 Nf5 15.Bf2 Rad8 16.Ng5 Bxg5 17.fxg5 Nfd4 18.Bxd4 Nxd4 19.Rxf8+ Kxf8 20.Kf2 b6 (608.168.428) 177
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Dann Corbit
Posts: 12540
Joined: Wed Mar 08, 2006 8:57 pm
Location: Redmond, WA USA

Re: Removal of the guard -- a very hard problem.

Post by Dann Corbit »

kgburcham wrote:Dan I let Rybka 3 run this position in the Chessbase interface and it did not list c5. In the Shredder interface Rybka 3 will choose c5 but then leaves it. Not much difference in eval before or after. At depth 22 eval is falling so maybe it would play c5 at greater depth. Maybe fischer would win with f6, c5, dxe5, or maybe another. I do not doubt that c5 is a good move but Rybka score stays -.5 until move 15.fxe6, after that white plays several moves with score increasing for black with each move. It seems to me the better player that day won the game by making less mistakes after move 15.

In the end the biggest loser was fischer, sad.
kgburcham

[D] rnbqnrk1/ppp1ppbp/3p2p1/4P3/2PP1P2/2N1B3/PP4PP/R2QKBNR b KQ -

Rybka 3 (shredder)

13.14 0:15 +0.13 7...f6 8.exd6 Nxd6 9.Qd2 Nc6 10.O-O-O Na5 11.b3 c6 (2.053.989) 134
14.01 0:20 +0.15 7...f6 8.exd6 Nxd6 9.Qd2 Nc6 10.O-O-O e5 11.dxe5 fxe5 12.c5 Nf7 13.Qf2 Qe8 14.Nd5 (2.640.774) 135
15.01 0:31 +0.20 7...f6 8.exd6 Nxd6 9.Nf3 Nc6 10.d5 Na5 11.Qa4 c6 12.O-O-O cxd5 13.c5 Nf5 14.Rxd5 (4.055.193) 131
15.04 0:48 +0.19 7...dxe5 8.dxe5 Qxd1+ 9.Rxd1 Nc6 10.Nd5 e6 11.Nc3 f6 (6.366.636) 133
16.01 0:59 +0.15 7...dxe5 8.dxe5 Qxd1+ 9.Rxd1 Nc6 10.Nf3 f6 11.exf6 Bxf6 12.Be2 Bxc3+ 13.bxc3 Nd6 14.c5 (8.021.257) 138
17.01 1:26 +0.18 7...dxe5 8.dxe5 Qxd1+ 9.Rxd1 Nc6 10.Nf3 f6 11.exf6 Bxf6 12.Be2 Nd6 13.Nb5 Ne8 14.Nbd4 Nxd4 15.Bxd4 Ng7 16.Bxf6 exf6 17.O-O Nf5 18.Rfe1 Ne3 (12.069.464) 142
18.01 2:34 +0.15 7...dxe5 8.dxe5 Qxd1+ 9.Rxd1 Nc6 10.Nf3 f6 11.exf6 Bxf6 12.Be2 Nd6 13.O-O Bxc3 14.bxc3 Be6 15.Nd2 Na5 16.c5 Ndc4 17.Bd4 Rad8 18.Bxc4 Bxc4 19.Rfe1 Rd7 20.Nxc4 (22.059.206) 146
19.01 4:09 +0.09 7...dxe5 8.dxe5 Qxd1+ 9.Rxd1 Nc6 10.Nf3 f6 11.exf6 Bxf6 12.Be2 Nd6 13.O-O Be6 14.c5 Nf5 15.Bf2 Ng7 16.g3 Rad8 17.a3 Bb3 18.Rd2 Nf5 19.Rxd8 Rxd8 20.Nb5 Rd7 (36.110.179) 148
20.01 7:56 +0.15 7...dxe5 8.dxe5 Qxd1+ 9.Rxd1 Nc6 10.Nf3 f6 11.exf6 Bxf6 12.Be2 Nd6 13.O-O Be6 14.c5 Nf5 15.Bf2 Rad8 16.Ng5 Bxg5 17.fxg5 Nfd4 (71.775.095) 154
20.12 19:14 +0.08 7...c5 8.dxc5 Nc6 (183.004.854) 162
21.01 39:11 +0.16 7...c5 8.dxc5 Nc6 9.cxd6 exd6 10.Nf3 Be6 11.Be2 Qa5 12.Qa4 Qxa4 13.Nxa4 dxe5 14.Bc5 exf4 15.O-O Bf5 16.Nc3 Nf6 17.Bxf8 Rxf8 18.Rad1 Ng4 19.Rd2 Bxc3 20.bxc3 Ne3 (403.825.612) 175
21.02 51:52 +0.15 7...dxe5 8.dxe5 Qxd1+ 9.Rxd1 Nc6 10.Nf3 f6 11.exf6 Bxf6 12.Be2 Nd6 13.O-O Be6 14.c5 Nf5 15.Bf2 Rad8 16.Ng5 Bxg5 17.fxg5 Nfd4 (539.896.194) 177
22.01 58:22 +0.14 7...dxe5 8.dxe5 Qxd1+ 9.Rxd1 Nc6 10.Nf3 f6 11.exf6 Bxf6 12.Be2 Nd6 13.O-O Be6 14.c5 Nf5 15.Bf2 Rad8 16.Ng5 Bxg5 17.fxg5 Nfd4 18.Bxd4 Nxd4 19.Rxf8+ Kxf8 20.Kf2 b6 (608.168.428) 177
You will notice that my search with the same engine (Rybka 3, 4x 3.0GHz, 600MB Ram for ~58 hours) does like the position and also that I got to depth 27 (5 plies deeper than your analysis).

I am totally convinced that c5 is the best move (I was actually pretty convinced of it before, but I had never got an engine to find it before).
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