One of the Hardest Combinations Ever Played

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jdart
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Re: One of the Hardest Combinations Ever Played

Post by jdart »

An analysis sideline from this position, discussed in this post:

http://www.chessgames.com/perl/chessgame?gid=1472988

is this endgame position:

[d] 4q1kr/4r2p/1p2P1pB/p3p3/4P3/1BP5/PP5P/5RK1 w - a6

with bm Bd5. This alone is pretty difficult - I tried it with Toga II and it started to see Bd5 was best around ply 22 (400+ seconds on my laptop) but was still not giving it a + score.

--Jon
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Kirk
Posts: 5702
Joined: Sat Mar 11, 2006 3:44 am

Re: One of the Hardest Combinations Ever Played

Post by Kirk »

jdart wrote:An analysis sideline from this position, discussed in this post:

http://www.chessgames.com/perl/chessgame?gid=1472988

is this endgame position:

[d] 4q1kr/4r2p/1p2P1pB/p3p3/4P3/1BP5/PP5P/5RK1 w - a6

with bm Bd5. This alone is pretty difficult - I tried it with Toga II and it started to see Bd5 was best around ply 22 (400+ seconds on my laptop) but was still not giving it a + score.

--Jon
Both engines came up a4 :?

Both a very different result in evaluation:

Spike 1.2 Turin

14.02 0:06 -2.43++ 1.Rf7 a4 2.Bd5 a3 3.bxa3 (1.893.526) 285.8
14.02 0:06 -2.43++ 1.Rf7 a4 2.Bd5 a3 3.bxa3 (1.893.526) 285.8
14.01 0:10 -1.87 1.Rf7 Rxf7 2.exf7+ Qxf7 3.Bd5 b5 4.Kg2 a4 5.Kg3 Qxd5 6.exd5 Kf7 7.Kf3 a3 8.b3 Rc8 (3.181.999) 302.5
14.01 0:11 -1.87 1.Rf7 Rxf7 2.exf7+ Qxf7 3.Bd5 b5 4.Kg2 a4 5.Kg3 Qxd5 6.exd5 Kf7 7.Kf3 a3 8.b3 Rc8 (3.331.502) 302.8
15.01 0:13 -1.90 1.Rf7 Rxf7 2.exf7+ Qxf7 3.Bd5 b5 4.Kg2 a4 5.Kg3 Qxd5 6.exd5 Kf7 7.Kf3 a3 8.b3 Rc8 9.Bd2 (3.987.857) 302.3
15.14 0:15 -1.90 1.Rf7 Rxf7 2.exf7+ Qxf7 3.Bd5 b5 4.Kg2 a4 5.Kg3 Qxd5 6.exd5 Kf7 7.Kf3 a3 8.b3 Rc8 9.Bd2 (4.724.520) 304.1
16.01 0:19 -2.02 1.Rf7 Rxf7 2.exf7+ Qxf7 3.Bd5 b5 4.Kg2 Qxd5 5.exd5 Kf7 6.Kf3 Rc8 7.Bg5 b4 8.Ke4 bxc3 9.bxc3 Rxc3 10.Kxe5 (6.052.089) 304.5
16.07 0:35 -1.69 1.a4 Qb8 2.Rf7 Qc8 3.Kg2 Qe8 4.Bg5 Rxf7 5.exf7+ Qxf7 6.Bxf7+ Kxf7 7.Be3 Rb8 8.c4 Ke6 9.b3 Rb7 (10.389.751) 295.1
16.13 0:36 -1.69 1.a4 Qb8 2.Rf7 Qc8 3.Kg2 Qe8 4.Bg5 Rxf7 5.exf7+ Qxf7 6.Bxf7+ Kxf7 7.Be3 Rb8 8.c4 Ke6 9.b3 Rb7 (10.674.963) 296.2
17.01 0:45 -1.39++ 1.a4 Qb8 2.Rf7 Qc8 3.Kg2 Qe8 4.Bd5 (13.462.581) 292.9
17.01 0:45 -1.39++ 1.a4 Qb8 2.Rf7 Qc8 3.Kg2 Qe8 4.Bd5 (13.462.581) 292.9
17.01 1:03 -1.11 1.a4 Qb8 2.Rf7 Qc8 3.Kg2 Qe8 4.Bd5 Rxf7 5.exf7+ Qxf7 6.c4 Qxd5 7.cxd5 Kf7 8.Be3 Rb8 9.Kf3 Ke7 10.Ke2 (18.812.013) 294.0
17.21 1:08 -1.11 1.a4 Qb8 2.Rf7 Qc8 3.Kg2 Qe8 4.Bd5 Rxf7 5.exf7+ Qxf7 6.c4 Qxd5 7.cxd5 Kf7 8.Be3 Rb8 9.Kf3 Ke7 10.Ke2 (20.337.132) 296.2
18.01 1:43 -0.81++ 1.a4 Qb8 2.Rf7 Qc8 3.Rf1 b5 4.axb5 a4 5.Bd5 (30.413.657) 292.5
18.01 1:43 -0.81++ 1.a4 Qb8 2.Rf7 Qc8 3.Rf1 b5 4.axb5 a4 5.Bd5 (30.413.657) 292.5
18.01 2:44 0.00 1.a4 Qb8 2.Rf7 Qc8 3.Rf1 Qe8 4.Bc4 Qb8 5.Rf7 Qc8 6.Rf1 b5 7.axb5 Qc5+ 8.Kg2 Qc8 9.Kg1 (47.805.144) 290.0
18.04 2:45 0.00 1.a4 Qb8 2.Rf7 Qc8 3.Rf1 Qe8 4.Bc4 Qb8 5.Rf7 Qc8 6.Rf1 b5 7.axb5 Qc5+ 8.Kg2 Qc8 9.Kg1 (48.113.359) 290.2
19.01 3:40 0.00 1.a4 Qb8 2.Rf7 Qc8 3.Rf1 Qe8 4.Bc4 Qb8 5.Rf7 Qc8 6.Rf1 Qe8 7.Bb3 (63.842.234) 289.0
19.03 3:43 0.00 1.a4 Qb8 2.Rf7 Qc8 3.Rf1 Qe8 4.Bc4 Qb8 5.Rf7 Qc8 6.Rf1 Qe8 7.Bb3 (64.606.668) 289.4
20.01 6:30 0.00 1.a4 Qb8 2.Rf7 Qc8 3.Rf1 Qe8 4.Bc4 Qb8 5.Rf7 Qc8 6.Rf1 Qe8 7.Bb3 (112.902.879) 288.8
20.07 6:36 0.00 1.a4 Qb8 2.Rf7 Qc8 3.Rf1 Qe8 4.Bc4 Qb8 5.Rf7 Qc8 6.Rf1 Qe8 7.Bb3 (114.658.853) 289.1
21.01 15:07 0.00 1.a4 Qb8 2.Rf7 Qc8 3.Rf1 Qe8 4.Bc4 Qb8 5.Rf7 Qc8 6.Rf1 Qe8 7.Bb3 (260.794.446) 287.3
21.31 15:14 0.00 1.a4 Qb8 2.Rf7 Qc8 3.Rf1 Qe8 4.Bc4 Qb8 5.Rf7 Qc8 6.Rf1 Qe8 7.Bb3 (263.105.908) 287.6
22.01 30:55 0.00 1.a4 Qb8 2.Rf7 Qc8 3.Rf1 Qe8 4.Bc4 Qb8 5.Rf7 Qc8 6.Rf1 Qe8 7.Bb3 (538.303.023) 290.1
22.15 31:11 0.00 1.a4 Qb8 2.Rf7 Qc8 3.Rf1 Qe8 4.Bc4 Qb8 5.Rf7 Qc8 6.Rf1 Qe8 7.Bb3 (543.746.508) 290.4
23.01 33:51 0.00 1.a4 Qb8 2.Rf7 Qc8 3.Rf1 Qe8 4.Bc4 Qb8 5.Rf7 Qc8 6.Rf1 Qe8 7.Bb3 (590.919.347) 290.9
best move: a2-a4 time: 33:51.156 min n/s: 290.934 CPU 49.2% nodes: 590.919.347

And Shredder 6 Tricky-Tahoma

13.01 0:13 +12.95++ 1.a4 Qd8 2.Rf7 Rxe6 3.Bxe6 Qa8 (8.180.496) 591.5
13.01 0:33 +13.45++ 1.a4 Qd8 2.Rf7 Qd1+ 3.Kf2 Qc2+ 4.Bxc2 Rxf7+ 5.exf7+ Kxf7 6.Be3 Rd8 7.h4 Ke6 8.Ke2 g5 9.Bxg5 (20.591.289) 611.8
13.01 0:46 +13.46 1.a4 Qd8 2.Rf7 Qd1+ 3.Kf2 Qc2+ 4.Bxc2 Rxf7+ 5.exf7+ Kxf7 6.Be3 Ke6 7.Bd3 Rb8 8.h4 Kd6 9.Ke2 (28.406.060) 615.4
14.01 1:34 +13.21-- 1.a4 Qd8 2.Rf7 Qd1+ 3.Kf2 Qd8 4.Rxe7 Qxe7 5.Be3 Qg7 6.Bxb6 Kf8 7.Bxa5 Qh6 (58.500.459) 616.3
14.01 1:54 +12.71-- 1.a4 Qd8 2.Rf7 Qe8 3.Rxe7 Qxe7 4.Bd5 Qc5+ 5.Be3 Qxe3+ 6.Kg2 Qxc3 7.bxc3 (72.517.711) 633.5
14.01 3:23 +12.71 1.a4 Qd8 2.Rf7 Qe8 3.Rxe7 Qxe7 4.Bd5 Qc5+ 5.Kg2 Qe7 6.b3 Qd6 7.e7+ Qe6 8.e8Q+ (135.349.573) 663.6
15.01 3:51 +12.96++ 1.a4 Qd8 2.Rf7 Qe8 3.Rxe7 Qxe7 4.Bd5 Qc5+ 5.Kg2 Qe7 6.b3 Qc5 7.e7+ Qxd5 8.e8Q+ (151.703.481) 656.7
15.01 4:00 +13.12 1.a4 Qd8 2.Rf7 Qd1+ 3.Bxd1 Rxf7 4.exf7+ Kxf7 5.Bb3+ Ke7 6.Be3 Rb8 7.Bd5 Kd7 8.b3 b5 9.axb5 (156.936.582) 653.5
16.01 5:35 +13.37++ 1.a4 Qd8 2.Rf7 Qd1+ 3.Bxd1 Rxf7 4.exf7+ Kxf7 5.Bb3+ Ke7 6.Be3 Rb8 7.Bd5 Kd7 8.c4 Kc7 9.Kf1 Rf8+ 10.Ke2 Rf4 (215.487.060) 641.5
16.01 13:12 +13.87++ 1.a4 Qd8 2.Rf7 Qd1+ 3.Kf2 Qd8 4.Rxe7 Qxe7 5.Kg1 Qc5+ 6.Kg2 Qe7 7.h4 b5 8.axb5 a4 9.Bd5 (481.277.546) 607.3
best move: a2-a4 time: 33:51.265 min n/s: 614.515 CPU 129.1% nodes: 1.248.244.680
“He knew all the tricks, dramatic irony, metaphor, pathos, puns, parody, litotes and... satire. He was vicious”
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Terry McCracken
Posts: 16465
Joined: Wed Aug 01, 2007 4:16 am
Location: Canada

Re: One of the Hardest Combinations Ever Played

Post by Terry McCracken »

Kirk wrote:
jdart wrote:An analysis sideline from this position, discussed in this post:

http://www.chessgames.com/perl/chessgame?gid=1472988

is this endgame position:

[d] 4q1kr/4r2p/1p2P1pB/p3p3/4P3/1BP5/PP5P/5RK1 w - a6

with bm Bd5. This alone is pretty difficult - I tried it with Toga II and it started to see Bd5 was best around ply 22 (400+ seconds on my laptop) but was still not giving it a + score.

--Jon
Both engines came up a4 :?

Both a very different result in evaluation:

Spike 1.2 Turin

14.02 0:06 -2.43++ 1.Rf7 a4 2.Bd5 a3 3.bxa3 (1.893.526) 285.8
14.02 0:06 -2.43++ 1.Rf7 a4 2.Bd5 a3 3.bxa3 (1.893.526) 285.8
14.01 0:10 -1.87 1.Rf7 Rxf7 2.exf7+ Qxf7 3.Bd5 b5 4.Kg2 a4 5.Kg3 Qxd5 6.exd5 Kf7 7.Kf3 a3 8.b3 Rc8 (3.181.999) 302.5
14.01 0:11 -1.87 1.Rf7 Rxf7 2.exf7+ Qxf7 3.Bd5 b5 4.Kg2 a4 5.Kg3 Qxd5 6.exd5 Kf7 7.Kf3 a3 8.b3 Rc8 (3.331.502) 302.8
15.01 0:13 -1.90 1.Rf7 Rxf7 2.exf7+ Qxf7 3.Bd5 b5 4.Kg2 a4 5.Kg3 Qxd5 6.exd5 Kf7 7.Kf3 a3 8.b3 Rc8 9.Bd2 (3.987.857) 302.3
15.14 0:15 -1.90 1.Rf7 Rxf7 2.exf7+ Qxf7 3.Bd5 b5 4.Kg2 a4 5.Kg3 Qxd5 6.exd5 Kf7 7.Kf3 a3 8.b3 Rc8 9.Bd2 (4.724.520) 304.1
16.01 0:19 -2.02 1.Rf7 Rxf7 2.exf7+ Qxf7 3.Bd5 b5 4.Kg2 Qxd5 5.exd5 Kf7 6.Kf3 Rc8 7.Bg5 b4 8.Ke4 bxc3 9.bxc3 Rxc3 10.Kxe5 (6.052.089) 304.5
16.07 0:35 -1.69 1.a4 Qb8 2.Rf7 Qc8 3.Kg2 Qe8 4.Bg5 Rxf7 5.exf7+ Qxf7 6.Bxf7+ Kxf7 7.Be3 Rb8 8.c4 Ke6 9.b3 Rb7 (10.389.751) 295.1
16.13 0:36 -1.69 1.a4 Qb8 2.Rf7 Qc8 3.Kg2 Qe8 4.Bg5 Rxf7 5.exf7+ Qxf7 6.Bxf7+ Kxf7 7.Be3 Rb8 8.c4 Ke6 9.b3 Rb7 (10.674.963) 296.2
17.01 0:45 -1.39++ 1.a4 Qb8 2.Rf7 Qc8 3.Kg2 Qe8 4.Bd5 (13.462.581) 292.9
17.01 0:45 -1.39++ 1.a4 Qb8 2.Rf7 Qc8 3.Kg2 Qe8 4.Bd5 (13.462.581) 292.9
17.01 1:03 -1.11 1.a4 Qb8 2.Rf7 Qc8 3.Kg2 Qe8 4.Bd5 Rxf7 5.exf7+ Qxf7 6.c4 Qxd5 7.cxd5 Kf7 8.Be3 Rb8 9.Kf3 Ke7 10.Ke2 (18.812.013) 294.0
17.21 1:08 -1.11 1.a4 Qb8 2.Rf7 Qc8 3.Kg2 Qe8 4.Bd5 Rxf7 5.exf7+ Qxf7 6.c4 Qxd5 7.cxd5 Kf7 8.Be3 Rb8 9.Kf3 Ke7 10.Ke2 (20.337.132) 296.2
18.01 1:43 -0.81++ 1.a4 Qb8 2.Rf7 Qc8 3.Rf1 b5 4.axb5 a4 5.Bd5 (30.413.657) 292.5
18.01 1:43 -0.81++ 1.a4 Qb8 2.Rf7 Qc8 3.Rf1 b5 4.axb5 a4 5.Bd5 (30.413.657) 292.5
18.01 2:44 0.00 1.a4 Qb8 2.Rf7 Qc8 3.Rf1 Qe8 4.Bc4 Qb8 5.Rf7 Qc8 6.Rf1 b5 7.axb5 Qc5+ 8.Kg2 Qc8 9.Kg1 (47.805.144) 290.0
18.04 2:45 0.00 1.a4 Qb8 2.Rf7 Qc8 3.Rf1 Qe8 4.Bc4 Qb8 5.Rf7 Qc8 6.Rf1 b5 7.axb5 Qc5+ 8.Kg2 Qc8 9.Kg1 (48.113.359) 290.2
19.01 3:40 0.00 1.a4 Qb8 2.Rf7 Qc8 3.Rf1 Qe8 4.Bc4 Qb8 5.Rf7 Qc8 6.Rf1 Qe8 7.Bb3 (63.842.234) 289.0
19.03 3:43 0.00 1.a4 Qb8 2.Rf7 Qc8 3.Rf1 Qe8 4.Bc4 Qb8 5.Rf7 Qc8 6.Rf1 Qe8 7.Bb3 (64.606.668) 289.4
20.01 6:30 0.00 1.a4 Qb8 2.Rf7 Qc8 3.Rf1 Qe8 4.Bc4 Qb8 5.Rf7 Qc8 6.Rf1 Qe8 7.Bb3 (112.902.879) 288.8
20.07 6:36 0.00 1.a4 Qb8 2.Rf7 Qc8 3.Rf1 Qe8 4.Bc4 Qb8 5.Rf7 Qc8 6.Rf1 Qe8 7.Bb3 (114.658.853) 289.1
21.01 15:07 0.00 1.a4 Qb8 2.Rf7 Qc8 3.Rf1 Qe8 4.Bc4 Qb8 5.Rf7 Qc8 6.Rf1 Qe8 7.Bb3 (260.794.446) 287.3
21.31 15:14 0.00 1.a4 Qb8 2.Rf7 Qc8 3.Rf1 Qe8 4.Bc4 Qb8 5.Rf7 Qc8 6.Rf1 Qe8 7.Bb3 (263.105.908) 287.6
22.01 30:55 0.00 1.a4 Qb8 2.Rf7 Qc8 3.Rf1 Qe8 4.Bc4 Qb8 5.Rf7 Qc8 6.Rf1 Qe8 7.Bb3 (538.303.023) 290.1
22.15 31:11 0.00 1.a4 Qb8 2.Rf7 Qc8 3.Rf1 Qe8 4.Bc4 Qb8 5.Rf7 Qc8 6.Rf1 Qe8 7.Bb3 (543.746.508) 290.4
23.01 33:51 0.00 1.a4 Qb8 2.Rf7 Qc8 3.Rf1 Qe8 4.Bc4 Qb8 5.Rf7 Qc8 6.Rf1 Qe8 7.Bb3 (590.919.347) 290.9
best move: a2-a4 time: 33:51.156 min n/s: 290.934 CPU 49.2% nodes: 590.919.347

And Shredder 6 Tricky-Tahoma

13.01 0:13 +12.95++ 1.a4 Qd8 2.Rf7 Rxe6 3.Bxe6 Qa8 (8.180.496) 591.5
13.01 0:33 +13.45++ 1.a4 Qd8 2.Rf7 Qd1+ 3.Kf2 Qc2+ 4.Bxc2 Rxf7+ 5.exf7+ Kxf7 6.Be3 Rd8 7.h4 Ke6 8.Ke2 g5 9.Bxg5 (20.591.289) 611.8
13.01 0:46 +13.46 1.a4 Qd8 2.Rf7 Qd1+ 3.Kf2 Qc2+ 4.Bxc2 Rxf7+ 5.exf7+ Kxf7 6.Be3 Ke6 7.Bd3 Rb8 8.h4 Kd6 9.Ke2 (28.406.060) 615.4
14.01 1:34 +13.21-- 1.a4 Qd8 2.Rf7 Qd1+ 3.Kf2 Qd8 4.Rxe7 Qxe7 5.Be3 Qg7 6.Bxb6 Kf8 7.Bxa5 Qh6 (58.500.459) 616.3
14.01 1:54 +12.71-- 1.a4 Qd8 2.Rf7 Qe8 3.Rxe7 Qxe7 4.Bd5 Qc5+ 5.Be3 Qxe3+ 6.Kg2 Qxc3 7.bxc3 (72.517.711) 633.5
14.01 3:23 +12.71 1.a4 Qd8 2.Rf7 Qe8 3.Rxe7 Qxe7 4.Bd5 Qc5+ 5.Kg2 Qe7 6.b3 Qd6 7.e7+ Qe6 8.e8Q+ (135.349.573) 663.6
15.01 3:51 +12.96++ 1.a4 Qd8 2.Rf7 Qe8 3.Rxe7 Qxe7 4.Bd5 Qc5+ 5.Kg2 Qe7 6.b3 Qc5 7.e7+ Qxd5 8.e8Q+ (151.703.481) 656.7
15.01 4:00 +13.12 1.a4 Qd8 2.Rf7 Qd1+ 3.Bxd1 Rxf7 4.exf7+ Kxf7 5.Bb3+ Ke7 6.Be3 Rb8 7.Bd5 Kd7 8.b3 b5 9.axb5 (156.936.582) 653.5
16.01 5:35 +13.37++ 1.a4 Qd8 2.Rf7 Qd1+ 3.Bxd1 Rxf7 4.exf7+ Kxf7 5.Bb3+ Ke7 6.Be3 Rb8 7.Bd5 Kd7 8.c4 Kc7 9.Kf1 Rf8+ 10.Ke2 Rf4 (215.487.060) 641.5
16.01 13:12 +13.87++ 1.a4 Qd8 2.Rf7 Qd1+ 3.Kf2 Qd8 4.Rxe7 Qxe7 5.Kg1 Qc5+ 6.Kg2 Qe7 7.h4 b5 8.axb5 a4 9.Bd5 (481.277.546) 607.3
best move: a2-a4 time: 33:51.265 min n/s: 614.515 CPU 129.1% nodes: 1.248.244.680
a4!! is Best! Black is busted.
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smirobth
Posts: 2307
Joined: Wed Mar 08, 2006 8:41 pm
Location: Brownsville Texas USA

Re: One of the Hardest Combinations Ever Played

Post by smirobth »

jdart wrote:An analysis sideline from this position, discussed in this post:

http://www.chessgames.com/perl/chessgame?gid=1472988

is this endgame position:

[d] 4q1kr/4r2p/1p2P1pB/p3p3/4P3/1BP5/PP5P/5RK1 w - a6

with bm Bd5. This alone is pretty difficult - I tried it with Toga II and it started to see Bd5 was best around ply 22 (400+ seconds on my laptop) but was still not giving it a + score.

--Jon
It seems like many moves win for White in this position. For example 1.Bd5, 1.a4, 1.Kg2 all leave Black with the same basic problem (only his queen can move and it can't leave the back rank due to Rf8#), and White with the same basic winning plan ... create a passed q-side pawn and run it down the board, then when the pawn is on the 7th rank play Rf7 and then Rxe7. Black is powerless to stop this plan, but there are so many pawn moves that have to be played first that computers don't see it.
- Robin Smith
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Kaj Soderberg

Re: One of the Hardest Combinations Ever Played

Post by Kaj Soderberg »

I saw Christophe Theron post that Chess Tiger 2007.1 Normal settings at certain points switches to Gambit settings (and probably vice versa, although not made explicit).

BTW Where is Christophe lately anyway? Taming a new Tiger?

Best regards,

Kaj
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