nice exchange sac from Rybka 4

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kgburcham
Posts: 2016
Joined: Sun Feb 17, 2008 4:19 pm

Re: nice exchange sac from Rybka 4

Post by kgburcham »

[D] 8/5p2/p4r2/1p2b1pp/P3P2k/2P2B1P/KP1R2P1/8 b - - 0 1


Nullmove disabled
Deep Fritz 12:

1...Rxf3 2.gxf3 Kxh3 3.axb5 axb5 4.Kb3 h4 5.c4 bxc4+ (-0.39) Depth: 19/36 00:00:23 556mN
1...Rxf3 2.gxf3 Kxh3 3.axb5 axb5 4.Kb3 h4 5.c4 bxc4+ (-0.39) Depth: 20/35 00:00:26 618mN
1...Rxf3 2.gxf3 Kxh3 3.axb5 axb5 4.Kb3 h4 5.c4 bxc4+ (-0.58) Depth: 21/38 00:00:40 950mN
1...Rxf3 2.gxf3 Kxh3 3.axb5 axb5 4.Kb3 Kg3 5.c4 bxc4+ (-0.56) Depth: 22/40 00:01:12 1680mN
1...Rxf3 2.gxf3 Kxh3 3.axb5 axb5 4.Kb3 Kg3 5.c4 bxc4+ (-0.66) Depth: 23/41 00:02:40 3791mN
1...Rxf3 2.gxf3 Kxh3 3.axb5 axb5 4.Kb3 Kg3 5.Rd3 h4 6.(-1.10) Depth: 24/43 00:06:36 9280mN


Default settings
Deep Fritz 12:

1...Rxf3 2.gxf3 Kxh3 3.Rd5 Bf4 4.b4 h4 5.c4 bxc4 (-0.80) Depth: 27/49 00:05:19 6619mN
1...Rxf3 2.gxf3 Kxh3 3.Rd7 f6 4.a5 h4 5.Ra7 Kg2 (-1.19) Depth: 28/49 00:06:52 8096mN
1...Rxf3 2.gxf3 Kxh3 3.Rd5 Bf4 4.c4 bxc4 5.Ra5 h4 (-1.39) Depth: 29/50 00:09:53 10980mN
1...Rxf3 2.gxf3 Kxh3 3.Rd5 Bf4 4.c4 bxc4 5.Ra5 h4 (-1.39) Depth: 30/50 00:10:55 11888mN
1...Rxf3 2.gxf3 Kxh3 3.Rd5 Bf4 4.c4 bxc4 5.Ra5 h4 (-0.96) Depth: 31/55 00:12:25 13192mN
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Eelco de Groot
Posts: 4567
Joined: Sun Mar 12, 2006 2:40 am
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Re: nice exchange sac from Rybka 4

Post by Eelco de Groot »

Rainbow Serpent needs a lot of re-searches to resolve the score at iteration twenty, it is still slightly positive in the end with a PV with the reply 3. b4. Not the 0.00 that Rybka finds.
37 milllion nodes to find Rxf3 is slightly faster than Stockfish but with only one thread and on my machine this is not so fast, with more threads maybe Rainbow Serpent would need many more nodes as well.


[D]8/5p2/p4r2/1p2b1pp/P3P2k/2P2B1P/KP1R2P1/8 b - -

Engine: Rainbow Serpent 1.7.1s(dc) Build 058 (Athlon 2009 MHz, 128 MB)
by Tord Romstad, Marco Costalba, Joona Kiiski

1.00 0:00 -0.36 1...bxa4 (470) 0

2.00 0:00 -0.80 1...bxa4 2.Rd7 (640) 1

2.00 0:00 -0.48 1...Rd6 2.Rxd6 Bxd6 3.axb5 axb5 (1.570) 2

3.00 0:00 -0.52 1...Rd6 2.Rxd6 Bxd6 3.Kb3 (3.941) 7

4.00 0:00 -0.52 1...Rd6 2.Rxd6 Bxd6 3.Kb3 g4 4.hxg4 hxg4 (6.549) 11

5.00 0:00 -0.60 1...Rd6 2.Rxd6 Bxd6 3.axb5 axb5
4.Kb3 (24.610) 39

5.00 0:00 -0.56 1...g4 2.hxg4 hxg4 3.Be2 Rf2 4.axb5 axb5 (27.204) 43

6.00 0:00 -0.48++ 1...g4 2.hxg4 hxg4 3.Be2 bxa4 4.Rd7 Rf2 (32.340) 49

6.00 0:00 -0.48 1...g4 2.hxg4 hxg4 3.Bd1 Rd6 4.Rxd6 Bxd6
5.Kb3 Kg5 6.axb5 axb5 (35.011) 52

7.00 0:00 -0.48 1...g4 2.hxg4 hxg4 3.Bd1 Rd6 4.Rxd6 Bxd6
5.Kb3 Kg5 6.axb5 axb5 (43.665) 63

8.00 0:00 -0.48 1...g4 2.hxg4 hxg4 3.Bd1 Rd6 4.Rxd6 Bxd6
5.Kb3 Kg5 6.axb5 axb5 (71.229) 93

9.00 0:00 -0.56-- 1...g4 2.hxg4 hxg4 3.Bd1 Rd6 4.Rxd6 Bxd6
5.Kb3 Kg5 6.axb5 axb5 7.Be2 (98.985) 117

9.01 0:01 -0.52 1...g4 2.hxg4 hxg4 3.Bd1 Rd6 4.Rxd6 Bxd6
5.Kb3 Kg5 6.Be2 bxa4+ 7.Kxa4 Kf4 (226.093) 164

10.01 0:01 -0.60-- 1...g4 2.hxg4 hxg4 3.Bd1 Rd6 4.Rxd6 Bxd6
5.Kb3 Kg5 6.axb5 axb5 7.Be2 (244.292) 171

10.05 0:02 -0.56 1...bxa4 2.Ka3 g4 3.hxg4 hxg4 4.Bd1 Rf4
5.Kxa4 f5 6.Ka5 fxe4 7.Kxa6 Kg3 (640.304) 251

11.01 0:02 -0.56 1...bxa4 2.Rd5 Bb8 3.e5 Rf4 4.Ka3 g4
5.hxg4 hxg4 6.Be2 Rf2 (725.516) 262

12.01 0:03 -0.48++ 1...bxa4 2.Rd5 Bb8 3.e5 Rf4 4.Ka3 g4
5.hxg4 hxg4 6.Be2 Rf2 (1.114.827) 292

12.01 0:04 -0.52 1...bxa4 2.Ka3 g4 3.Bd1 Rf4 4.Kxa4 f5
5.hxg4 hxg4 6.Ka5 fxe4 7.Kxa6 Kg3
8.Rd5 Bf6 (1.439.470) 306

13.01 0:05 -0.52 1...bxa4 2.Ka3 g4 3.Bd1 Rf4 4.Kxa4 f5
5.hxg4 hxg4 6.Ka5 fxe4 7.Kxa6 Kg3
8.Rd5 Bf6 (1.854.386) 318

14.01 0:07 -0.44++ 1...bxa4 2.Rd5 Bb8 3.e5 Rf4 4.Ka3 g4
5.hxg4 hxg4 6.Be2 Rf2 (2.577.547) 330

14.01 0:10 -0.52 1...bxa4 2.Rd5 Bb8 3.Rd8 Be5 4.Re8 Re6
5.Rxe6 fxe6 6.Ka3 g4 7.hxg4 hxg4
8.Be2 Kg3 9.Kxa4 Kf4 10.Kb4 Kxe4
11.Bxa6 (3.391.230) 339

15.01 0:18 -0.44++ 1...bxa4 2.Ka3 g4 3.Bd1 Rf4 4.hxg4 hxg4
5.Bxa4 Kg3 6.Bd7 Rxe4 7.Bc6 Re1
8.Kb4 f5 9.Bb7 f4 10.Bxa6 f3 (6.374.284) 353

15.01 0:33 -0.36++ 1...bxa4 2.Rd5 Re6 3.Ka3 g4 4.Bd1 Kg3
5.hxg4 h4 6.Bf3 h3 7.Kxa4 h2 (11.818.539) 350

15.01 0:41 -0.32 1...bxa4 2.Rd5 Re6 3.Ra5 g4 4.hxg4 hxg4
5.Be2 Kg3 6.Kb1 Bc7 7.Rxa4 f5 8.Bxa6 Rxe4
9.Rxe4 fxe4 10.Be2 Kxg2 11.Bxg4 Kg3 (14.599.846) 351

16.01 0:47 -0.28 1...bxa4 2.Rd5 Re6 3.Ra5 g4 4.hxg4 hxg4
5.Be2 Kg3 6.Bxa6 Bb8 7.Bc8 Rxe4
8.Bb7 Rf4 9.Bd5 f5 10.c4 Be5 11.Rxa4 (16.567.377) 351

17.01 1:05 -0.24 1...bxa4 2.Rd5 Re6 3.Ka3 g4 4.hxg4 hxg4
5.Bd1 Bf4 6.Bxa4 Rxe4 7.Rf5 Bc1
8.Rxf7 Re2 9.Bc6 Rxb2 10.Ka4 Be3 (22.910.291) 348

17.07 1:45 0.00++ 1...Rxf3 2.gxf3 Kxh3 3.axb5 axb5
4.Rd7 f6 5.Kb3 Kg3 6.Rd3 h4 7.Kb4 Kg2
8.Kc5 h3 (37.019.098) 350

17.07 1:55 +0.28++ 1...Rxf3 2.gxf3 Kxh3 3.axb5 axb5
4.Rd7 f6 5.Kb3 Kg3 6.Rd3 h4 7.Kb4 Kg2
8.Kc5 h3 (40.757.046) 354

17.07 2:15 +0.84++ 1...Rxf3 2.gxf3 Kxh3 3.axb5 axb5
4.Rd7 f6 5.Kb3 Kg3 6.Rd3 h4 7.Kb4 Kg2
8.Kc5 (48.156.016) 356

17.07 2:37 +0.92 1...Rxf3 2.gxf3 Kxh3 3.axb5 axb5
4.Kb3 h4 5.c4 bxc4+ 6.Kxc4 Kg3 7.Kd5 Bf4
8.Rd1 Kxf3 9.b4 g4 10.Rf1+ Ke3 11.b5 g3
12.Re1+ Kf2 13.Rh1 h3 14.Rxh3 g2 (56.261.032) 356

18.01 3:20 +0.84 1...Rxf3 2.gxf3 Kxh3 3.axb5 axb5
4.Rd5 f6 5.Rxb5 Kg3 6.c4 h4 7.Rxe5 fxe5
8.c5 h3 9.c6 h2 10.c7 h1Q 11.c8Q Qxf3
12.Qf5 g4 13.Qxe5+ Kg2 14.b4 g3 (72.347.437) 361

19.01 4:13 +0.80 1...Rxf3 2.gxf3 Kxh3 3.axb5 axb5
4.Rd5 f6 5.Rxb5 Kg3 6.c4 h4 7.Rxe5 fxe5
8.c5 h3 9.c6 h2 10.c7 h1Q 11.c8Q Qxf3
12.Qf5 g4 13.Qxe5+ Kg2 14.b4 g3 (91.720.583) 361

20.01 6:05 +0.64-- 1...Rxf3 2.gxf3 Kxh3 3.axb5 axb5
4.Rd5 f6 5.Rxb5 Kg3 6.c4 h4 7.Rxe5 fxe5
8.c5 h3 9.c6 h2 10.c7 h1Q 11.c8Q Qxf3
12.Qf5 g4 13.Qxe5+ Kg2 14.b4 g3 (140.661.741) 384

20.01 7:26 +0.96++ 1...Rxf3 2.gxf3 Kxh3 3.axb5 axb5
4.Rd5 Bf4 5.Rf5 Kg3 6.Rxf7 h4 7.Rh7 h3
8.c4 bxc4 (169.739.951) 380

20.01 8:33 +1.13++ 1...Rxf3 2.gxf3 Kxh3 3.axb5 axb5
4.Rd5 Bf4 5.Rf5 Kg3 6.Rxf7 h4 7.Rh7 h3
8.c4 bxc4 (194.865.748) 379

20.01 10:03 +1.45++ 1...Rxf3 2.gxf3 Kxh3 3.axb5 axb5
4.Rd5 Bf4 5.Rf5 Kg3 6.Rxf7 h4 7.Rh7 h3
8.c4 bxc4 (228.499.064) 378

20.01 13:49 +2.10++ 1...Rxf3 2.gxf3 Kxh3 3.axb5 axb5
4.Rd5 Bf4 5.Rf5 Kg3 6.Rxf7 h4 7.Rh7 h3
8.c4 bxc4 9.e5 Bxe5 10.Kb1 h2 (310.405.534) 373

20.01 51:24 +1.33-- 1...Rxf3 2.gxf3 Kxh3 3.b4 h4 4.c4 Bf4
5.Rd7 bxa4 6.Rxf7 Kg3 7.Rxf4 gxf4
8.e5 h3 9.e6 h2 10.e7 h1Q 11.e8Q Qc1
12.Qe2 Qc3 13.b5 Qb3+ 14.Ka1 Qe3 (1.193.892.745) 387

20.01 59:55 +1.45-- 1...Rxf3 2.gxf3 Kxh3 3.b4 h4 4.c4 Bf4
5.Rd7 bxa4 6.Rxf7 Kg3 7.Rxf4 gxf4
8.e5 h3 9.e6 h2 10.e7 h1Q 11.e8Q Qc1
12.Qe2 Qc3 13.b5 Qb3+ 14.Ka1 Qe3 (1.516.327.986) 421

20.01 61:56 +1.25 1...Rxf3 2.gxf3 Kxh3 3.b4 h4 4.c4 Bf4
5.Rd7 bxa4 6.Rxf7 Kg3 7.Rxf4 gxf4
8.e5 h3 9.e6 h2 10.e7 h1Q 11.e8Q Qc1
12.Qe2 Qc3 13.c5 Qb3+ 14.Ka1 Qxb4 (1.586.009.258) 426

best move: Rf6xf3 time: 69:34.937 min n/s: 451.971 nodes: 1.886.940.422
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
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Robert Flesher
Posts: 1280
Joined: Tue Aug 18, 2009 3:06 am

Re: nice exchange sac from Rybka 4

Post by Robert Flesher »

yanquis1972 wrote:yes, as kg & dann show, it appears only to draw:


1... Rxf3 2. gxf3 Kxh3 3. Rd5 f6 4. axb5 axb5 5. Rxb5 h4 6. Rxe5 fxe5 7. c4 Kg3 8. c5 h3 9. c6 h2 10. c7 h1=Q 11. c8=Q Qxf3 12. Qf5

Perhaps its a draw, but I am not sure yet. In the line you give, F6 ? allowing the exchange sac is weak. Bf4! is much better! Then white has to contend with the passers. Bah.... I found the draw here too! So I guess f6 is not so weak :roll:

1... Rxf3 2. gxf3 Kxh3 3. Rd5 Bf4 4. c4 !
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