an ending where no engine finds the truth

[dr_zied_haddad]

Here is the position. All the engines gives the advantage for black. But it's probably a draw.

8/8/5p2/4p1k1/R5p1/5bK1/8/8 w - -

Try your engines (even Rybka3 is out of order).

[Dr.Wael Deeb]

[d]8/8/5p2/4p1k1/R5p1/5bK1/8/8 w - -

[ernest]

(even Rybka3 is out of order).

Analysis by Rybka 3 32-bit:
1.Ra5 Be4 2.Rc5 Bb7 3.Ra5 Bc6 4.Rc5
-/+ (-0.87) Depth: 31 00:01:26 9463kN, tb=23100
1.Ra5 Be4 2.Rc5 Bb7 3.Ra5 Bc6 4.Rc5
-/+ (-0.87) Depth: 32 00:01:56 13086kN, tb=34036

-0.87 eval does seem compatible with a draw...

[Dann Corbit]

None of my engines knew it was a draw, but *all* of them told me unambiguously that it was a draw.

When you see this lack of progress on very deep searches:

Code: Select all

Analysis from Q:\epd\sub\drawq.epd   
11/26/2008 2:41:27 PM Level: Tournament Game in one Minute
Analyzing engine: Rybka 3

1) "Is it a draw?";     
    Avoid move: 
    Best move (Rybka 3): Ra4-a5
    Not found in: 03:00
      7	00:00	          68	4.096	-0.90	Ra4a5 Bf3c6 Ra5c5 Bc6a8 Rc5b5 Ba8e4
      8	00:00	          77	4.638	-0.90	Ra4a5 Bf3c6 Ra5c5 Bc6a8 Rc5b5 Ba8e4
      9	00:00	          87	5.240	-0.90	Ra4a5 Bf3c6 Ra5c5 Bc6a8 Rc5b5 Ba8e4 Rb5c5 Be4b7 Rc5b5
     10	00:00	          98	2.090	-0.89	Ra4a5 Bf3c6 Ra5c5 Bc6a8 Rc5b5 Ba8e4 Rb5c5
     11	00:00	         108	2.304	-0.89	Ra4a5 Bf3c6 Ra5c5 Bc6a8 Rc5b5 Ba8e4 Rb5c5
     12	00:00	         238	3.808	-0.89	Ra4a5 Bf3c6 Ra5c5 Bc6a8 Rc5b5 Ba8e4 Rb5c5 Be4f5 Rc5a5
     13	00:00	         656	7.070	-0.89	Ra4a5 Bf3c6 Ra5c5 Bc6a8 Rc5b5 Ba8e4 Rb5c5 Be4g6
     14	00:00	       1.442	10.398	-0.89	Ra4a5 Bf3c6 Ra5c5 Bc6a8 Rc5b5 Ba8e4 Rb5c5 Be4g6
     15	00:00	       4.207	21.117	-0.89	Ra4a5 Bf3c6 Ra5c5 Bc6a8 Rc5b5 Ba8e4 Rb5c5 Be4g6
     16	00:00	      12.349	42.434	-0.89	Ra4a5 Bf3c6 Ra5c5 Bc6a8 Rc5b5 Ba8e4 Rb5c5 Be4g6
     17	00:00	      18.738	49.073	-0.89	Ra4a5 Bf3c6 Ra5c5 Bc6a8 Rc5b5 Ba8e4 Rb5c5 Be4g6
     18	00:00	      28.018	52.450	-0.89	Ra4a5 Bf3c6 Ra5c5 Bc6a8 Rc5b5 Ba8e4 Rb5c5 Be4g6
     19	00:00	      32.351	42.416	-0.89	Ra4a5 Bf3c6 Ra5c5 Bc6a8 Rc5b5 Ba8e4 Rb5c5 Be4g6
     20	00:01	      47.867	40.744	-0.89	Ra4a5 Bf3c6 Ra5c5 Bc6a8 Rc5b5 Ba8e4 Rb5c5
     21	00:01	      55.626	36.119	-0.89	Ra4a5 Bf3c6 Ra5c5 Bc6a8 Rc5b5 Ba8e4 Rb5c5 Be4g6
     22	00:02	     101.155	44.841	-0.89	Ra4a5 Bf3c6 Ra5c5 Bc6a8 Rc5b5 Ba8e4 Rb5c5 Be4g6
     23	00:03	     124.119	38.409	-0.89	Ra4a5 Bf3c6 Ra5c5 Bc6a8 Rc5b5 Ba8e4 Rb5c5 Be4g6
     24	00:05	     151.496	32.071	-0.89	Ra4a5 Bf3c6 Ra5c5 Bc6a8 Rc5b5 Ba8e4 Rb5c5 Be4g6
     25	00:07	     265.003	37.239	-0.89	Ra4a5 Bf3c6 Ra5c5 Bc6a8 Rc5b5 Ba8e4 Rb5c5 Be4g6
     26	00:11	     329.590	29.838	-0.89	Ra4a5 Bf3c6 Ra5c5 Bc6a8 Rc5b5 Ba8e4 Rb5c5 Be4g6
     27	00:15	     489.723	32.968	-0.89	Ra4a5 Bf3c6 Ra5c5 Bc6a8 Rc5b5 Ba8e4 Rb5c5 Be4g6
     28	00:23	     777.594	33.577	-0.89	Ra4a5 Bf3c6 Ra5c5 Bc6a8 Rc5b5 Ba8e4 Rb5c5 Be4g6
     29	00:33	   1.083.985	33.704	-0.89	Ra4a5 Bf3c6 Ra5c5 Bc6a8 Rc5b5 Ba8e4 Rb5c5 Be4g6
     30	00:48	   1.681.709	35.448	-0.89	Ra4a5 Bf3c6 Ra5c5 Bc6a8 Rc5b5 Ba8e4 Rb5c5 Be4g6
     31	01:02	   2.296.820	37.898	-0.89	Ra4a5 Bf3c6 Ra5c5 Bc6a8 Rc5b5 Ba8e4 Rb5c5 Be4g6
     32	01:22	   3.575.502	44.449	-0.89	Ra4a5 Bf3c6 Ra5c5 Bc6a8 Rc5b5 Ba8e4 Rb5c5 Be4g6
     33	01:56	   5.551.430	49.023	-0.89	Ra4a5 Bf3c6 Ra5c5 Bc6a8 Rc5b5 Ba8e4 Rb5c5 Be4g6
     34	02:44	   9.157.551	56.944	-0.89	Ra4a5 Bf3c6 Ra5c5 Bc6a8 Rc5b5 Ba8e4 Rb5c5 Be4g6
   11/26/2008 5:02:17 PM, Time for this analysis: 00:03:00, Rated time: 03:00

0 of 1 matching moves
11/26/2008 5:02:18 PM, Total time: 2:20:50 AM
Rated time: 03:00 = 180 Seconds

then you can know that the position is drawn unless there is a better plan that is being overlooked.

[swami]

None of my engines knew it was a draw, but *all* of them told me unambiguously that it was a draw.

When you see this lack of progress on very deep searches:

From human perspective, this is without doubt a draw.

[dr_zied_haddad]

This ending is from one of my correspondance games. It finished as a draw. I was playing with Black. A long sicilian, very very interesting with plenty of Black sacrifices. I choose a sharp line where i sacrificed to play for a win against a player which got a +3 score against me. Unfortunately for me, my opponent (an excellent player), played very well. I was near winning, but i suppose i misunderestimated my opponent manoeuvring with his rook to exchange with my rook. I think i overlooked something between moves 30-35. Here is my game. Any suggestions?

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 Nc6
6. Bg5 Bd7 7. Qd2 Nxd4 8. Qxd4 Qa5 9. Bd2 Rc8 10. f3 e5
11. Qf2 a6 12. a3 Be6 13. g4 Be7 14. O-O-O O-O 15. h4 Qc7
16. Be3 b5 17. h5 Qb7 18. g5 Nd7 19. Qd2 Nb6 20. g6 Nc4
21. Bxc4 Rxc4 22. gxh7+ Kxh7 23. Nd5 Rfc8 24. c3 a5 25. Nxe7 Qxe7
26. Qxd6 Rc4xc3+ 27. bxc3 Rxc3+ 28. Kb2 Qxd6 29. Rxd6 Rxe3 30. Rb6 Rb3+ 31. Kc2 Bc4 32. a4 bxa4 33. Rc6 Be2 34. Ra1 f6 35. Rxa4 Rxf3
36. Rc5 Rf4 37. Rcxa5 Bxh5 38. Kd3 Bf3 39. Ke3 g5 40. Ra5a8 Kg6
41. Rh8 g4 42. Rg8+ Kh5 43. Rh8+ Kg5 44. Rg8+ Kh4 45. Rh8+ Kg3
46. Rh5 Bg2 47. Rf5 Rxf5 48. exf5 Kh4 49. Kf2 Bf3 50. Ra6 Kg5
51. Kg3 Kxf5 52. Ra4 Kg5 53. Ra5 Kf5 54. Ra4 Bd5 *

[kgburcham]

Both sides of this game were using a program. Which program were you using?

kgburcham

[Dr.Wael Deeb]

Both sides of this game were using a program. Which program were you using?

kgburcham

And how did you end up with this conclusion