OpenChess

From Division 2 of an on-going GM tournament:
[FEN "6k1/1R3p1p/1P3rp1/1p6/8/5PK1/6PP/8 w - - 0 37"]
[White "Wojtaszek"]
[Black "Navara"]
[Result "0-1"]
37. Kf2 b4 38. Ke2 Rd6 39. Rb8+ Kg7 40. b7 Rb6 41. Kd2 b3 42. Kc1 h5 43. h4 b2+ 44. Kb1 f5 45. f4 Rb4 46. g3 Rb3 47. Re8 Rxb7 48. Re3 Rb6 49. Re7+ Kf6 50. Re3 Kf7 51. Ra3 Ke6 52. Rd3 Ke7 53. Ra3 Kd7 54. Ra7+ Ke6 55. Ra3 Kd5 56. Rc3 Kd4 57. Ra3 Kc4 58. Ra4+ Kd3 0-1White has a bit of difficulties, but I think this should be drawn. Various analysis spouting about seems rather faulty, based upon annotation by result perhaps.

White's 43. h4 is just asking for trouble if you ask me. A clearer path to the draw seems to me to be 43. Kb2. However, it still seems like White can draw, if he gives up the b-pawn a bit sooner. In particular, the weakening 45. f4 is not to be recommended. Instead, 45. Rc8 Rxb7 46. Rc4, and White just shuttles on the fourth rank Ra4-c4-a4-f4 (if necessary). Eventually Black plays g5 (exchanging Rooks on the b-file leads to a drawn pawn endgame), upon which White exchanges pawns and plays g3. For instance:
8/8/1r6/5pkp/2R5/5PP1/1p6/1K6 b - - 0 58Black can't win here: 58... Rb3 59. Rc8 Kf6 60. Rc6+ Ke5 61. Rc5+ Ke6 62. Rc6+ Kd5 63. Rh6 Rxf3 64. Rxh5 Ke4 65. Rg5 Rf2 and draw. White has enough checking distance.

Any improvements?

Maybe Black can try 46. Rc4 Kf6 47. Ra4 Ke5 48. Rc4 Rd6!?, but I think White again draws after 49. f4+ Ke6 50. Rb4 Rd1+ 51. Kxb2 Rd2+ 52. Kc3 Rxg2 53. Rb6, and even if Black wins another pawn he cannot win. Same with 49. f4+ Kf6 50. Kxb2 Rd2+ 51. Kc3 Rxg2 52. Ra6+, and Black will find his King too harassed and his Rook too off-side to co-ordinate to victory. A typical position:R7/8/6pk/4Kp1p/5r1P/8/8/8 b - - 1 58And Black can make no progress, as far as I can tell, with the classical draw with f- and h-pawns creeping into play.

[I meant to put a after the subject title, but failed to do so].

Another try: 45. Rc8 Rxb7 46. Rc4 Kf6 47. Ra4 Ke5 48. Rc4 Rd7 49. g3 Rd3 50. Rc6 Rd6 51. Rc4 Rb6, and I think Black wins now. The push of the g-pawn weakened f3, and so Black can play Rb3 with effect in many lines. White should probably play 49. f4+ Kd5 50. Ra4 Re7 51. Kxb2 Re2+ 52. Kc2 Rxg2, and then it looks difficult, as again Black can win 2 pawns, but the end result is not clear. 53. Kd3 Rg3+ 54. Ke2 Rg4 55. Kf3 Rxh4 56. Ra7 Rg4 -- can White hold? All I can say is that I see no win for Black, which is perhaps not the greatest evidence in the world.

I still haven't looked at whether White can do better by blocking the b-pawn one square earlier.

As a side-note, maybe White should not play Ra4 when the Black King is on e6, as Black then plays Ke5, and White is forced to play Rc4. From that configuration, Black can then play Rd6, and after f4+ will attack the Rook via Kd5, gaining a vital tempo. For example, I don't think White can hold this:8/8/3r2p1/4kp1p/2R4P/5P2/1p4P1/1K6 w - - 10 51But if the Rook is on a4 instead, I still can't find a win for Black.

Similarly, the Rook should not move to f4 when the Black King is on d6, as else Kd5, Ra4 Ke5, Rc4 Rd6 as above, and White is in trouble. So there is subtlety.

Starting from the initial position, I can't see how White lost the game, but again, my chess knowledge is not all that. The game was played out using much weaker 32-bit single core vs Houdini on quad core.

[Event "Computer chess game"]
[Site "W0111D0001"]
[Date "2011.01.17"]
[Round "?"]
[White "Dragon-4.6"]
[Black "Houdini 1.5 x64"]
[Result "1/2-1/2"]
[BlackElo "2800"]
[WhiteElo "2400"]
[TimeControl "300+0"]
[SetUp "1"]
[FEN "6k1/1R3p1p/1P3rp1/1p6/8/5PK1/6PP/8 w - - 0 37"]
[Termination "normal"]
[PlyCount "118"]
[WhiteType "program"]
[BlackType "program"]

37. Rb8+ {(37.Rb7-b8+ Kg8-g7 38.Kg3-f2 b5-b4 39.Kf2-e3 b4-b3 40.Ke3-d2
Rf6-c6 41.b6-b7 Rc6-b6 42.Kd2-c1 b3-b2+ 43.Kc1-b1 Rb6-b3 44.h2-h4 f7-f5
45.g2-g4) +0.11/14 7} Kg7 {(37. ... Kg8-g7) -0.60/1 0} 38. Kf2 {(38.Kg3-f2
b5-b4 39.Kf2-e3 b4-b3 40.Ke3-d2 Rf6-c6 41.b6-b7 Rc6-b6 42.Kd2-c1 b3-b2+
43.Kc1-b1 Kg7-f6 44.g2-g4 Rb6-b3 45.f3-f4 h7-h5) +0.08/15 7} b4 {(38. ...
b5-b4 39.Kf2-e2 b4-b3 40.Ke2-d2 Rf6-c6 41.b6-b7 Rc6-b6 42.Kd2-c1 b3-b2+
43.Kc1-b1 Kg7-f6 44.h2-h4 h7-h5 45.g2-g4 Rb6-b4 46.g4xh5 g6xh5 47.Rb8-h8
Rb4xb7 48.Rh8xh5 Rb7-b3 49.Rh5-c5 Rb3xf3 50.Kb1xb2 Kf6-g6 51.Rc5-g5+ Kg6-h6
52.Kb2-c2 Rf3-f4 53.Kc2-d3 Rf4xh4 54.Rg5-g1 Rh4-h5 55.Kd3-e3 Rh5-g5
56.Rg1-d1 Rg5-e5+ 57.Ke3-f4) +0.09/24 4} 39. Ke3 {(39.Kf2-e3 b4-b3
40.Ke3-d2 Rf6-c6 41.b6-b7 Rc6-b6 42.Kd2-c1 b3-b2+ 43.Kc1-b1 h7-h5 44.f3-f4
Rb6-b3 45.h2-h4 f7-f5) +0.06/14 7} b3 {(39. ... b4-b3 40.Ke3-d2 Rf6-c6
41.b6-b7 Rc6-b6 42.Kd2-c1 b3-b2+ 43.Kc1-b1 Kg7-f6 44.Rb8-h8 Rb6xb7
45.Rh8xh7 Rb7-e7 46.h2-h4 Re7-e2 47.g2-g4 Re2-f2 48.g4-g5+ Kf6-e6 49.f3-f4
Rf2-d2 50.Rh7-h8 Rd2-h2 51.Rh8-h6 Rh2-e2 52.Rh6-h8 Ke6-f5 53.Rh8-f8 Re2-e7
54.Kb1xb2 Kf5xf4 55.Kb2-c3 Kf4-g4 56.Rf8-h8 Re7-e3+ 57.Kc3-d4 Re3-h3
58.Rh8-h7 Rh3xh4 59.Rh7xf7 Kg4xg5+ 60.Kd4-e5) +0.12/24 6} 40. Kd2
{(40.Ke3-d2 Rf6-c6 41.b6-b7 Rc6-b6 42.Kd2-c1 b3-b2+ 43.Kc1-b1 Kg7-f6
44.h2-h4 Kf6-f5 45.g2-g3 Rb6-b3 46.h4-h5 g6xh5 47.Rb8-e8) +0.03/14 6} Rc6
{(40. ... Rf6-c6 41.b6-b7 Rc6-b6 42.Kd2-c1 b3-b2+ 43.Kc1-b1 Kg7-f6
44.Rb8-h8 Rb6xb7 45.Rh8xh7 Rb7-e7 46.h2-h4 Re7-e2 47.g2-g4 Re2-f2 48.g4-g5+
Kf6-e6 49.f3-f4 Rf2-d2 50.Rh7-h8 Rd2-h2 51.Rh8-h6 Rh2-e2 52.Rh6-h8 Ke6-f5
53.Rh8-f8 Re2-e7 54.Kb1xb2 Kf5xf4 55.Kb2-c3 Kf4-g4 56.Rf8-h8 Re7-e3+
57.Kc3-d4 Re3-h3 58.Rh8-h7 Rh3xh4 59.Rh7xf7 Kg4xg5+ 60.Kd4-e5) +0.12/24 0}
41. b7 {(41.b6-b7 Rc6-b6 42.Kd2-c1 b3-b2+ 43.Kc1-b1 Kg7-f6 44.h2-h3 g6-g5
45.Rb8-c8 Rb6xb7 46.Rc8-c6+ Kf6-e5 47.Rc6-c5+) -0.11/13 6} Rb6 {(41. ...
Rc6-b6 42.Kd2-c1 b3-b2+ 43.Kc1-b1 Kg7-f6 44.Rb8-h8 Rb6xb7 45.Rh8xh7 Rb7-e7
46.h2-h4 Re7-e2 47.g2-g4 Re2-f2 48.g4-g5+ Kf6-e6 49.Kb1-a2 Rf2-d2 50.Ka2-b1
Rd2-e2 51.Rh7-h8 Re2-h2 52.Rh8-e8+ Ke6-f5 53.Re8-h8 Kf5-e5 54.Rh8-h7 Ke5-e6
55.Rh7-h8 Ke6-f5 56.Rh8-h7 f7-f6 57.g5xf6 Kf5xf6 58.Rh7-b7 Rh2-f2 59.Kb1-a2
Rf2xf3 60.Ka2xb2 Rf3-f4 61.Rb7-h7 Rf4-f3 62.Rh7-a7 Rf3-h3 63.Ra7-a6+ Kf6-f5
64.Ra6-a4 Rh3-e3 65.Ra4-a6 Re3-d3 66.Ra6-a5+ Kf5-f4 67.Ra5-a4+ Kf4-e5)
+0.12/26 4} 42. Kc1 {(42.Kd2-c1 b3-b2+ 43.Kc1-b1 Kg7-f6 44.h2-h3 g6-g5
45.Rb8-d8 Rb6xb7 46.Rd8-d2 Kf6-f5 47.Rd2xb2 Rb7xb2+ 48.Kb1xb2 Kf5-f4
49.Kb2-a3) -0.23/14 6} b2+ {(42. ... b3-b2+ 43.Kc1-b1 Kg7-f6 44.Rb8-h8
Rb6xb7 45.Rh8xh7 Rb7-e7 46.h2-h4 Re7-e2 47.g2-g4 Re2-f2 48.g4-g5+ Kf6-e6
49.Kb1-a2 Rf2-d2 50.Ka2-b1 Rd2-e2 51.Rh7-h8 Re2-h2 52.Rh8-e8+ Ke6-f5
53.Re8-h8 Kf5-e5 54.Rh8-h7 Ke5-e6 55.Rh7-h8 Ke6-f5 56.Rh8-h7 f7-f6 57.g5xf6
Kf5xf6 58.Rh7-b7 Rh2-f2 59.Kb1-a2 Rf2xf3 60.Ka2xb2 Rf3-f4 61.Rb7-h7 Rf4-f3
62.Rh7-a7 Rf3-h3 63.Ra7-a6+ Kf6-f5 64.Ra6-a4 Rh3-e3 65.Ra4-a6 Re3-d3
66.Ra6-a5+ Kf5-f4 67.Ra5-a4+ Kf4-e5) +0.12/25 0} 43. Kb1 {(43.Kc1-b1 Kg7-f6
44.Rb8-e8 Rb6xb7 45.Re8-e2 Kf6-f5 46.Re2-e4 Rb7-b3 47.Re4-e2 Kf5-f4
48.Re2-e4+ Kf4-g5 49.Re4-e2 f7-f6 50.Re2xb2 f6-f5) -0.37/16 6} Rb3 {(43.
... Rb6-b3 44.Rb8-d8 Rb3xb7 45.Rd8-d2 Rb7-b5 46.Rd2xb2 Rb5-h5 47.h2-h3
Kg7-f6 48.Kb1-c2 Kf6-g5 49.Rb2-b4 Rh5-h4 50.Rb4-b2 Kg5-f4 51.Rb2-a2 Rh4-h5
52.Kc2-c3 Kf4-g3 53.Kc3-c4 Rh5-e5 54.Kc4-d3 Re5-e7 55.Kd3-d4 Kg3-f4
56.Kd4-d5 h7-h5 57.Ra2-a4+ Kf4-g3 58.Ra4-a2 h5-h4) +0.10/26 47} 44. Re8
{(44.Rb8-e8 Rb3xb7 45.Re8-e2 f7-f5 46.Re2xb2 Rb7-e7 47.g2-g3 Kg7-f7
48.f3-f4 h7-h5 49.Kb1-c1 Re7-a7 50.Rb2-d2 Ra7-b7 51.Rd2-d8) -0.14/16 6}
Rxb7 {(44. ... Rb3xb7 45.Re8-e2 Rb7-b5 46.Re2xb2 Rb5-h5 47.g2-g3 Rh5-c5
48.Rb2-c2 Rc5-f5 49.f3-f4 Rf5-b5+ 50.Kb1-c1 Kg7-f6 51.Kc1-d2 Kf6-f5
52.Kd2-e3 Rb5-b3+ 53.Ke3-f2 h7-h5 54.Kf2-g2 Kf5-g4 55.h2-h3+ Kg4-f5
56.Rc2-a2 Rb3-c3 57.Ra2-a7 f7-f6) +0.09/24 1} 45. Re2 {(45.Re8-e2 Kg7-f6
46.Re2xb2 Rb7xb2+ 47.Kb1xb2 Kf6-e5 48.Kb2-c3 Ke5-f4 49.Kc3-d3 h7-h5
50.Kd3-e2 h5-h4 51.Ke2-f2 Kf4-e5 52.Kf2-e3 f7-f5) -0.19/15 6} Rb5 {(45. ...
Rb7-b5 46.Re2xb2 Rb5-h5 47.g2-g3 Rh5-c5 48.Rb2-c2 Rc5-f5 49.f3-f4 Rf5-b5+
50.Kb1-c1 Kg7-f6 51.Kc1-d2 Kf6-f5 52.Kd2-e3 Kf5-g4 53.Ke3-f2 Kg4-h3
54.Kf2-e3 Rb5-b4 55.Rc2-d2 h7-h5 56.Rd2-e2 Kh3-g4 57.Re2-d2 Rb4-b3+
58.Ke3-e4 f7-f6) +0.09/24 3} 46. Rxb2 {(46.Re2xb2 Rb5xb2+ 47.Kb1xb2 Kg7-f6
48.Kb2-c3 Kf6-e5 49.g2-g3 f7-f5 50.h2-h3 h7-h5 51.Kc3-d3 g6-g5 52.h3-h4
f5-f4 53.g3xf4+ g5xf4) -0.11/15 5} Rh5 {(46. ... Rb5-h5 47.g2-g3 Rh5-c5
48.Rb2-c2 Rc5-f5 49.f3-f4 Rf5-b5+ 50.Kb1-c1 Kg7-f6 51.Rc2-c7 h7-h5
52.Kc1-c2 h5-h4 53.Rc7-c6+ Kf6-f5 54.Rc6-c7 f7-f6 55.Rc7-c6 Rb5-a5
56.Kc2-b3 h4xg3 57.h2xg3 Ra5-a1 58.Rc6-d6 Ra1-g1 59.Rd6-d5+ Kf5-g4)
+0.09/24 13} 47. g3 {(47.g2-g3 h7-h6 48.f3-f4 g6-g5 49.Rb2-d2 g5xf4
50.g3xf4 Kg7-f6 51.Rd2-f2 Rh5-a5 52.Rf2-e2 Ra5-a4 53.h2-h3) -0.04/13 5} Rc5
{(47. ... Rh5-c5 48.Rb2-c2 Rc5-f5 49.Rc2-f2 Rf5-e5 50.Kb1-c2 Re5-e3
51.Kc2-d2 Re3-a3 52.Kd2-e1 Ra3-a1+ 53.Ke1-d2 h7-h6 54.Kd2-c3 Kg7-f6
55.f3-f4 Kf6-f5 56.Rf2-b2 Ra1-a3+ 57.Kc3-d4 Ra3-a4+ 58.Kd4-e3 Ra4-e4+
59.Ke3-f3) +0.09/23 13} 48. Rc2 {(48.Rb2-c2 Rc5-e5 49.Kb1-c1 Re5-e3
50.f3-f4 h7-h5 51.Kc1-d2 Re3-b3) -0.01/13 5} Rd5 {(48. ... Rc5-d5 49.Kb1-b2
Rd5-d3 50.Rc2-c3 Rd3-d1 51.Rc3-c1 Rd1-d6 52.Rc1-c3 Rd6-e6 53.f3-f4 Kg7-f6
54.h2-h3 Re6-e2+ 55.Rc3-c2 Re2-e1 56.Rc2-c6+ Kf6-f5 57.Rc6-c5+ Kf5-e6
58.Kb2-c2 Ke6-d6 59.Rc5-c8) +0.09/21 4} 49. Kc1 {(49.Kb1-c1 h7-h5 50.Rc2-c3
g6-g5 51.h2-h3 Kg7-g6 52.Kc1-c2 Rd5-a5 53.Kc2-d3 Ra5-a2 54.Rc3-c6+ f7-f6
55.Rc6-c2 Ra2xc2) -0.05/13 8} Rd3 {(49. ... Rd5-d3 50.Rc2-f2 Kg7-f6
51.Kc1-c2 Rd3-a3 52.Kc2-d2 Kf6-e5 53.Kd2-e2 Ra3-a2+ 54.Ke2-e3 Ra2xf2
55.Ke3xf2 Ke5-d4 56.Kf2-e2 g6-g5 57.Ke2-d2 f7-f5 58.h2-h3 f5-f4 59.g3xf4
g5xf4 60.h3-h4 h7-h6 61.h4-h5 Kd4-e5 62.Kd2-d3) +0.14/24 3} 50. f4
{(50.f3-f4 h7-h5 51.Rc2-d2 Rd3-f3 52.Kc1-d1 h5-h4 53.Kd1-e2 Rf3-c3
54.Rd2-d3 Rc3-c2+ 55.Rd3-d2 Rc2xd2+ 56.Ke2xd2 h4-h3 57.Kd2-e3) -0.06/14 5}
h5 {(50. ... h7-h5 51.Rc2-d2 Rd3-c3+ 52.Kc1-b2 Rc3-e3 53.Kb2-c2 Kg7-f6
54.Rd2-d6+ Re3-e6 55.Rd6-d2 Kf6-f5 56.Rd2-d7 f7-f6 57.Kc2-d3 Re6-a6
58.Rd7-b7 h5-h4 59.Kd3-e3 Kf5-g4 60.g3xh4 Ra6-e6+ 61.Ke3-f2 Kg4xf4
62.Rb7-b4+ Re6-e4 63.Rb4-b6 Kf4-f5 64.h4-h5 g6xh5) +0.23/25 7} 51. Rd2
{(51.Rc2-d2 Rd3-c3+ 52.Kc1-b2 Rc3-e3 53.Kb2-c2 Kg7-f6 54.Rd2-d6+ Kf6-f5
55.Rd6-d7 Kf5-e6 56.Rd7-d8 h5-h4 57.g3xh4 Re3-f3) -0.16/14 4} Ra3 {(51. ...
Rd3-a3 52.Kc1-d1 h5-h4 53.g3xh4 Ra3-h3 54.f4-f5 g6xf5 55.Kd1-e1 Rh3xh4
56.Ke1-f1 Rh4-a4 57.Kf1-g2 Kg7-g6 58.Kg2-f3 Kg6-g5 59.Rd2-g2+ Ra4-g4
60.Rg2-d2 Rg4-f4+ 61.Kf3-e3 Rf4-a4 62.Rd2-g2+ Kg5-f6 63.Rg2-c2 f5-f4+
64.Ke3-f3 Kf6-e5 65.Rc2-c3 Ra4-a2 66.Rc3-c5+ Ke5-d4) +0.26/24 4} 52. Kb2
{(52.Kc1-b2 Ra3-e3 53.Kb2-c2 Kg7-f6 54.Rd2-d6+ Kf6-f5 55.Rd6-d7 Kf5-e6
56.Rd7-d8 Re3-e2+ 57.Rd8-d2 Ke6-e7) -0.16/14 4} Re3 {(52. ... Ra3-e3
53.Rd2-f2 h5-h4 54.g3-g4 Kg7-f6 55.Kb2-c2 Re3-e1 56.Kc2-d2 Re1-g1 57.f4-f5
g6-g5 58.h2-h3 Rg1-g3 59.Rf2-h2 Rg3-a3 60.Rh2-h1 Kf6-e5 61.Kd2-c2 Ra3-g3
62.Kc2-b2 Ke5-f4 63.Rh1-h2 Rg3-e3 64.Kb2-c2 Kf4-e5 65.Kc2-d2 Re3-a3
66.Rh2-h1 Ke5-d4 67.Kd2-c2 Ra3-c3+ 68.Kc2-b2 Rc3-e3 69.Kb2-c2 Kd4-e5
70.Kc2-d2 Re3-a3 71.Kd2-c2) +0.29/23 4} 53. Kc2 {(53.Kb2-c2 Kg7-f6
54.Rd2-d6+ Kf6-f5 55.Rd6-d7 f7-f6 56.Kc2-d2 Re3-b3 57.Kd2-e1 h5-h4
58.Rd7-c7) -0.25/14 4} Kf6 {(53. ... Kg7-f6 54.Rd2-d6+ Kf6-f5 55.Kc2-d2
Re3-a3 56.Rd6-d7 Ra3-a2+ 57.Kd2-e3 Kf5-e6 58.Rd7-c7 Ra2xh2 59.Rc7-c6+
Ke6-f5 60.Rc6-c5+ Kf5-f6 61.Ke3-f3 Rh2-b2 62.Rc5-c6+ Kf6-g7 63.Rc6-c3
Rb2-b1 64.Kf3-e4 Rb1-a1 65.Rc3-d3 Ra1-a4+ 66.Ke4-f3 Ra4-a8 67.Rd3-b3 Ra8-a1
68.Kf3-e4 Ra1-a2 69.Rb3-c3 Ra2-b2 70.Ke4-f3 Rb2-b1) +0.36/24 3} 54. Rd6+
{(54.Rd2-d6+ Kf6-f5 55.Rd6-d7 Kf5-e6 56.Rd7-d2 h5-h4 57.Rd2-d3 Re3-e4
58.Rd3-d8 Re4-a4 59.Rd8-e8+ Ke6-d7 60.Re8-h8 Ra4-a2+ 61.Kc2-b3 Ra2-f2)
-0.26/13 4} Kf5 {(54. ... Kf6-f5 55.Kc2-d2 Re3-a3 56.Rd6-d7 Ra3-a2+
57.Kd2-e3 Kf5-e6 58.Rd7-c7 Ra2xh2 59.Rc7-c6+ Ke6-f5 60.Rc6-c5+ Kf5-f6
61.Ke3-f3 Rh2-b2 62.Rc5-c6+ Kf6-g7 63.Rc6-c3 Rb2-b1 64.Kf3-e4 Rb1-a1
65.Rc3-d3 Ra1-e1+ 66.Ke4-f3 Re1-b1 67.Rd3-a3 Kg7-f6 68.Kf3-f2 Rb1-b5)
+0.36/25 2} 55. Kd2 {(55.Kc2-d2 Re3-a3 56.Rd6-d7 f7-f6 57.Rd7-d5+ Kf5-g4
58.Rd5-d6 g6-g5) -0.65/14 6} Ra3 {(55. ... Re3-a3 56.Rd6-d7 Ra3-a2+
57.Kd2-e3 Kf5-e6 58.Rd7-c7 Ra2xh2 59.Rc7-c6+ Ke6-f5 60.Rc6-c5+ Kf5-f6
61.Ke3-f3 Rh2-b2 62.Rc5-c6+ Kf6-g7 63.Rc6-c3 Rb2-b1 64.Kf3-e4 Rb1-a1
65.Ke4-f3 Ra1-a7 66.Rc3-b3 f7-f6 67.Kf3-e3 Kg7-f7 68.Ke3-f3 Ra7-d7
69.Rb3-c3 Rd7-d2 70.Kf3-e4) +0.36/26 3} 56. Rd7 {(56.Rd6-d7 f7-f6
57.Rd7-d5+ Kf5-e6 58.Rd5-c5 Ra3-a2+ 59.Rc5-c2 Ra2-a4) -0.96/13 4} Ra2+
{(56. ... Ra3-a2+ 57.Kd2-e3 Kf5-e6 58.Rd7-c7 Ra2xh2 59.Rc7-c6+ Ke6-f5
60.Rc6-c5+ Kf5-f6 61.Ke3-f3 Rh2-b2 62.Rc5-c6+ Kf6-g7 63.Rc6-c3 Rb2-h2
64.Rc3-c5 Rh2-a2 65.Rc5-c6 Ra2-d2 66.Rc6-c3 Rd2-d1 67.Rc3-c7 Kg7-f6
68.Rc7-b7 Rd1-e1 69.Rb7-c7 Kf6-e6 70.Rc7-b7 Re1-f1+ 71.Kf3-g2 Rf1-c1
72.Rb7-b2 Rc1-d1 73.Rb2-b7 Rd1-d7 74.Rb7-b5 Rd7-d6 75.Rb5-b7 f7-f6
76.Kg2-h3 Ke6-f5 77.Rb7-b5+ Kf5-e4) +0.36/26 4} 57. Ke3 {(57.Kd2-e3 Kf5-e6
58.Rd7-d2 Ra2xd2 59.Ke3xd2 Ke6-f5 60.Kd2-e3 Kf5-g4 61.Ke3-f2 h5-h4
62.Kf2-g2 h4-h3+) -0.28/14 4} Ke6 {(57. ... Kf5-e6 58.Rd7-c7 Ra2xh2
59.Rc7-c6+ Ke6-f5 60.Rc6-c5+ Kf5-f6 61.Ke3-f3 Rh2-b2 62.Rc5-c6+ Kf6-g7
63.Rc6-c3 Rb2-h2 64.Rc3-c5 Rh2-a2 65.Rc5-c6 Ra2-d2 66.Rc6-c3 Rd2-d1
67.Rc3-c7 Kg7-f6 68.Rc7-b7 Rd1-e1 69.Rb7-c7 Re1-f1+ 70.Kf3-e3 Rf1-a1
71.Ke3-f3 Ra1-a3+ 72.Kf3-f2 Kf6-e6 73.Kf2-g2 f7-f6 74.Kg2-h3 Ra3-d3
75.Rc7-a7 Rd3-d4 76.Ra7-b7 Rd4-d3 77.Rb7-c7 g6-g5 78.f4xg5 f6xg5 79.Rc7-c5
Rd3-d5) +0.36/26 4} 58. Rb7 {(58.Rd7-b7 Ra2xh2 59.Rb7-b6+ Ke6-f5 60.Rb6-b5+
Kf5-f6 61.Rb5-b6+ Kf6-g7 62.Rb6-c6 h5-h4 63.g3xh4 Rh2xh4 64.Rc6-d6)
-0.92/15 16} Rxh2 {(58. ... Ra2xh2 59.Rb7-b6+ Ke6-f5 60.Rb6-b5+ Kf5-f6
61.Ke3-f3 Rh2-c2 62.Rb5-b6+ Kf6-g7 63.Rb6-b3 Rc2-h2 64.Rb3-b6 Rh2-d2
65.Rb6-b7 Rd2-a2 66.Rb7-c7 Ra2-b2 67.Rc7-c3 Rb2-h2 68.Rc3-c5 Rh2-d2
69.Rc5-c3 Rd2-d1 70.Rc3-c7 Kg7-f6 71.Rc7-b7 Kf6-e6 72.Rb7-b6+ Rd1-d6
73.Rb6-b3 f7-f6 74.Rb3-c3 Rd6-d1 75.Rc3-c6+ Ke6-e7 76.Kf3-e4 Rd1-a1
77.Rc6-c2 Ra1-a3) +0.36/26 5} 59. Rb6+ {(59.Rb7-b6+ Ke6-f5 60.Rb6-b5+
Kf5-f6 61.Rb5-b6+ Kf6-g7 62.Rb6-c6 h5-h4 63.g3xh4 Rh2-h3+ 64.Ke3-e4 Rh3xh4
65.Ke4-e5 Rh4-h3) -0.87/13 3} Kf5 {(59. ... Ke6-f5 60.Rb6-b5+ Kf5-f6
61.Ke3-f3 Rh2-c2 62.Rb5-b6+ Kf6-g7 63.Rb6-b3 Rc2-h2 64.Rb3-a3 Rh2-d2
65.Ra3-e3 Rd2-d1 66.Kf3-g2 Kg7-f6 67.Kg2-h3 Rd1-g1 68.Re3-a3 Rg1-h1+
69.Kh3-g2 Rh1-c1 70.Ra3-a6+ Kf6-e7 71.Ra6-a7+ Ke7-f6 72.Kg2-h3) +0.36/26 2}
60. Rb5+ {(60.Rb6-b5+ Kf5-f6 61.Rb5-b6+ Kf6-g7 62.Rb6-d6 Rh2-b2) -0.85/13
3} Kf6 {(60. ... Kf5-f6 61.Ke3-f3 Rh2-c2 62.Rb5-b6+ Kf6-g7 63.Rb6-b3 Rc2-h2
64.Rb3-a3 Rh2-d2 65.Ra3-e3 Rd2-d1 66.Kf3-g2 Kg7-f6 67.Re3-e5 Rd1-d7
68.Kg2-h3 Rd7-e7 69.Re5-a5 Re7-e3 70.Ra5-a7 Re3-b3 71.Ra7-a5 Rb3-d3
72.Ra5-b5 Kf6-e7 73.Rb5-b7+ Ke7-e6 74.Rb7-b6+ Ke6-f5 75.Rb6-b5+ Kf5-f6
76.Rb5-b7 Kf6-e6 77.Rb7-b6+) +0.36/27 4} 61. Rb6+ {(61.Rb5-b6+ Kf6-g7)
-0.88/13 3} Kg7 {(61. ... Kf6-g7 62.Rb6-b5 Rh2-a2 63.Ke3-f3 Ra2-a3+
64.Kf3-g2 Ra3-d3 65.Rb5-b7 Kg7-f6 66.Kg2-h3 Kf6-e6 67.Kh3-h4 Rd3-f3
68.Rb7-b6+ Ke6-e7 69.Rb6-b7+ Ke7-f6 70.Rb7-b6+ Kf6-g7 71.Rb6-a6 Rf3-f1
72.Kh4-h3 Rf1-h1+ 73.Kh3-g2 Rh1-e1 74.Ra6-a7 Re1-e3 75.Ra7-b7 Re3-d3
76.Rb7-c7 Rd3-a3 77.Kg2-h3 Kg7-f6 78.Rc7-b7 Ra3-d3 79.Rb7-b5 Kf6-e7
80.Rb5-e5+ Ke7-f8 81.Kh3-g2 Rd3-a3 82.Re5-c5 Kf8-e7 83.Rc5-c7+ Ke7-e6
84.Kg2-h3 Ra3-d3 85.Kh3-h4 Rd3-a3 86.g3-g4 h5xg4 87.Kh4xg4 f7-f5+ 88.Kg4-g5
Ra3-g3+ 89.Kg5-h6) +0.36/26 2} 62. Rd6 {(62.Rb6-d6 Rh2-c2 63.Ke3-f3 Rc2-c7
64.Kf3-e3 Rc7-e7+ 65.Ke3-d4 f7-f5 66.Kd4-d3 Kg7-f7 67.Rd6-d4 Kf7-e6
68.Rd4-d8) -0.95/13 3} Rc2 {(62. ... Rh2-c2 63.Rd6-b6 Rc2-g2 64.Ke3-f3
Rg2-a2 65.Rb6-b7 Ra2-h2 66.Rb7-d7 Kg7-f6 67.Rd7-d6+ Kf6-f5 68.Rd6-d5+
Kf5-e6 69.Rd5-e5+ Ke6-f6 70.Re5-e3 Rh2-h1 71.Kf3-g2 Rh1-d1 72.Re3-e5 Rd1-d7
73.Kg2-h3 Rd7-e7 74.Re5-a5 Re7-e3 75.Ra5-a7 Re3-d3 76.Ra7-b7 Kf6-e6
77.Kh3-h4 Rd3-f3 78.Rb7-b6+ Ke6-e7 79.Rb6-b7+ Ke7-f6 80.Rb7-b6+ Kf6-g7
81.Rb6-a6 Rf3-f1 82.Kh4-h3 Rf1-h1+ 83.Kh3-g2 Rh1-e1 84.Ra6-a7 Re1-e3
85.Ra7-b7 Re3-d3 86.Rb7-c7 Rd3-a3 87.Kg2-h3 Kg7-f6 88.Rc7-b7 Ra3-d3
89.Rb7-b5 Kf6-e7 90.Rb5-b7+ Ke7-e6 91.Kh3-h4) +0.36/25 2} 63. Kf3
{(63.Ke3-f3 Rc2-c7 64.Kf3-e3 Rc7-e7+ 65.Ke3-d4 f7-f5 66.Kd4-d3 Re7-e4
67.Rd6-d7+ Kg7-f6 68.Rd7-c7 h5-h4) -0.95/13 3} Rc8 {(63. ... Rc2-c8
64.Rd6-d7 Kg7-f6 65.Kf3-g2 Rc8-c2+ 66.Kg2-h3 Kf6-e6 67.Rd7-a7 Rc2-c4
68.Ra7-a6+ Ke6-f5 69.Ra6-a5+ Kf5-f6 70.Ra5-a7 Kf6-g7 71.Ra7-b7 Rc4-c3
72.Rb7-b6 Rc3-e3 73.Rb6-b7 Kg7-f6 74.Rb7-a7 Re3-e7 75.Ra7-a4 Re7-d7
76.g3-g4 h5xg4+ 77.Kh3xg4) +0.36/26 2} 64. Ke2 {(64.Kf3-e2 Rc8-e8+
65.Ke2-d3 f7-f5 66.Rd6-d4 Kg7-h6 67.Kd3-d2 Kh6-h7) -0.97/12 2} Re8+ {(64.
... Rc8-e8+ 65.Ke2-f3 f7-f5 66.Kf3-g2 Kg7-f7 67.Kg2-h3 Re8-e6 68.Rd6-d7+
Kf7-f6 69.Rd7-b7 Re6-e2 70.Rb7-b8 Re2-e7 71.Rb8-a8 Re7-e6 72.Ra8-f8+ Kf6-e7
73.Rf8-a8 Re6-d6 74.Kh3-h4 Ke7-f6 75.Ra8-f8+ Kf6-g7 76.Rf8-b8 Rd6-d3
77.Rb8-b7+ Kg7-f6 78.Rb7-a7 Rd3-b3 79.Ra7-a6+ Kf6-f7 80.Kh4-h3 Rb3-d3
81.Ra6-a7+ Kf7-f6 82.Ra7-a6+ Kf6-f7 83.Ra6-a7+) +0.36/24 2} 65. Kf3
{(65.Ke2-f3 f7-f6 66.Rd6-d7+ Kg7-f8 67.Kf3-f2 g6-g5 68.f4xg5 h5-h4)
-0.99/14 2} f5 {(65. ... f7-f5 66.Kf3-g2 Kg7-f7 67.Kg2-h3 Re8-e6 68.Rd6-d7+
Kf7-f6 69.Rd7-b7 Re6-e2 70.Rb7-b8 Re2-e7 71.Rb8-a8 Re7-e6 72.Ra8-f8+ Kf6-e7
73.Rf8-a8 Re6-d6 74.Kh3-h4 Rd6-d3 75.Ra8-a6 Ke7-f7 76.Ra6-a7+ Kf7-f6
77.Ra7-a6+ Kf6-g7 78.Ra6-b6 Rd3-c3 79.Rb6-a6 Rc3-b3 80.Ra6-a7+ Kg7-f6
81.Ra7-a6+ Kf6-f7 82.Kh4-h3 Rb3-d3 83.Ra6-a7+ Kf7-f6 84.Ra7-a6+ Kf6-f7
85.Ra6-a7+) +0.36/27 2} 66. Kf2 {(66.Kf3-f2 Kg7-f7 67.Kf2-f3 Re8-e7
68.Kf3-f2 Re7-e6 69.Rd6-d7+ Kf7-f6) -1.00/14 2} Kf7 {(66. ... Kg7-f7
67.Rd6-b6 Re8-e6 68.Rb6-b8 Re6-d6 69.Kf2-g2 Kf7-f6 70.Rb8-b7 Rd6-d2+
71.Kg2-h3 Rd2-d3 72.Rb7-b6+ Kf6-g7 73.Rb6-a6 Rd3-b3 74.Kh3-h4 Kg7-f7
75.Ra6-a7+ Kf7-f6 76.Ra7-a6+ Kf6-g7 77.Ra6-a5 Rb3-e3 78.Ra5-a7+ Kg7-f6
79.Ra7-a6+ Kf6-f7 80.Ra6-b6 Kf7-g7 81.Rb6-b5 Re3-c3 82.Rb5-b7+ Kg7-f6
83.Rb7-b6+ Kf6-f7 84.Rb6-b7+ Kf7-f6 85.Rb7-b6+) +0.36/28 2} 67. Rc6
{(67.Rd6-c6 Re8-e4 68.Kf2-f3 Re4-e7 69.Rc6-c8 Re7-e6 70.Rc8-c7+) -1.00/14
2} Re6 {(67. ... Re8-e6 68.Rc6-c8 Re6-a6 69.Rc8-b8 Kf7-f6 70.Kf2-f3 Ra6-e6
71.Kf3-f2 Re6-c6 72.Kf2-g2 Rc6-c2+ 73.Kg2-h3 Kf6-g7 74.Rb8-b7+ Kg7-h6
75.Rb7-b6 Rc2-c3 76.Kh3-h4 Rc3-a3 77.Rb6-c6 Ra3-b3 78.Rc6-a6 Kh6-g7
79.Ra6-a5 Rb3-e3 80.Ra5-a7+ Kg7-f6 81.Ra7-a6+ Kf6-f7 82.Ra6-b6 Kf7-g7
83.Rb6-b7+ Kg7-f6 84.Rb7-b6+ Kf6-f7 85.Rb6-a6 Re3-b3 86.Ra6-a7+ Kf7-f6
87.Ra7-a6+ Kf6-g7 88.Ra6-a5) +0.36/28 2} 68. Rc7+ {(68.Rc6-c7+ Kf7-f6
69.Kf2-f3 Re6-b6 70.Kf3-e3 g6-g5 71.f4xg5+ Kf6xg5 72.Rc7-g7+ Kg5-f6
73.Rg7-h7 Rb6-e6+ 74.Ke3-d3 Kf6-g5 75.Rh7-g7+ Kg5-h6 76.Rg7-f7 Re6-g6
77.Kd3-d4) -1.02/14 2} Kf6 {(68. ... Kf7-f6 69.Rc7-b7 Re6-e7 70.Rb7-b6+
Kf6-f7 71.Kf2-g2 Re7-d7 72.Kg2-f3 Rd7-d3+ 73.Kf3-g2 Rd3-d2+ 74.Kg2-h3
Rd2-e2 75.Rb6-b7+ Kf7-f6 76.Rb7-b8 Re2-e7 77.Rb8-a8 Re7-e6 78.Ra8-f8+
Kf6-e7 79.Rf8-a8 Re6-d6 80.Kh3-h4 Rd6-d3 81.Ra8-a6 Ke7-f7 82.Kh4-h3 Rd3-c3
83.Ra6-a7+ Kf7-f6 84.Ra7-a6+ Kf6-g7 85.Kh3-h4 Rc3-b3 86.Ra6-a5 Rb3-e3
87.Ra5-a7+ Kg7-f6 88.Ra7-a6+ Kf6-f7 89.Ra6-b6 Kf7-g7 90.Rb6-b7+ Kg7-f6
91.Rb7-b6+ Kf6-f7 92.Rb6-a6 Re3-b3 93.Ra6-a7+ Kf7-f6 94.Ra7-a6+ Kf6-g7
95.Ra6-a5) +0.36/30 2} 69. Kf3 {(69.Kf2-f3 Re6-b6 70.Kf3-e3 g6-g5 71.f4xg5+
Kf6xg5 72.Rc7-g7+ Kg5-f6 73.Rg7-g8 Rb6-b3+ 74.Ke3-f2 Rb3-d3 75.Rg8-f8+
Kf6-g5 76.Rf8-g8+ Kg5-h6 77.Rg8-f8 Kh6-g6 78.Rf8-e8) -1.05/14 2} Ra6 {(69.
... Re6-a6 70.Kf3-g2 Ra6-b6 71.Rc7-a7 Rb6-d6 72.Ra7-b7 Rd6-d2+ 73.Kg2-h3
Rd2-d3 74.Rb7-b6+ Kf6-g7 75.Rb6-a6 Rd3-b3 76.Kh3-h4 Kg7-f7 77.Ra6-a7+
Kf7-f6 78.Ra7-a6+ Kf6-g7 79.Ra6-a5 Rb3-e3 80.Ra5-a7+ Kg7-f6 81.Ra7-c7
Re3-a3 82.Rc7-c6+ Kf6-g7 83.Rc6-c7+ Kg7-h6 84.Kh4-h3 Ra3-f3 85.Rc7-c6
Kh6-g7 86.Rc6-c7+ Kg7-h6 87.Rc7-c6) +0.36/29 2} 70. Ke3 {(70.Kf3-e3 Kf6-e6
71.Rc7-g7 Ke6-d5 72.Rg7-d7+ Kd5-c4 73.Rd7-c7+ Kc4-b3 74.Rc7-d7 Ra6-e6+
75.Ke3-d3 Re6-e4 76.Rd7-d4 Re4xd4+ 77.Kd3xd4 Kb3-c2) -1.06/13 2} Rb6 {(70.
... Ra6-b6 71.Rc7-c8 Kf6-e6 72.Rc8-e8+ Ke6-d5 73.Re8-d8+ Kd5-c6 74.Rd8-c8+
Kc6-d7 75.Rc8-g8 Kd7-e7 76.Rg8-c8 Rb6-b3+ 77.Ke3-f2 Ke7-f6 78.Rc8-c6+
Kf6-g7 79.Kf2-g2 Kg7-f7 80.Rc6-c7+ Kf7-f6 81.Rc7-c6+ Kf6-g7 82.Rc6-c7+
Kg7-h6 83.Kg2-h3 Rb3-a3 84.Rc7-c6 Kh6-g7 85.Kh3-h4 Ra3-b3 86.Rc6-a6 Kg7-f7
87.Ra6-a7+ Kf7-f6 88.Ra7-a6+ Kf6-g7 89.Ra6-a5 Rb3-e3 90.Ra5-a7+ Kg7-f6
91.Ra7-c7 Re3-a3 92.Rc7-c6+ Kf6-f7 93.Rc6-c7+ Kf7-f6 94.Rc7-c6+) +0.36/27
2} 71. Rd7 {(71.Rc7-d7 Kf6-e6 72.Rd7-d8 Rb6-c6 73.Ke3-d3 Rc6-a6 74.Kd3-c2)
-1.04/13 2} Rb3+ {(71. ... Rb6-b3+ 72.Ke3-f2 Kf6-e6 73.Rd7-c7 Rb3-d3
74.Rc7-g7 Ke6-f6 75.Rg7-b7 Rd3-a3 76.Rb7-b6+ Kf6-g7 77.Rb6-c6 Ra3-b3
78.Kf2-g2 Kg7-f7 79.Rc6-c7+ Kf7-f6 80.Rc7-c6+ Kf6-g7 81.Rc6-c7+ Kg7-h6
82.Kg2-h3 Rb3-a3 83.Rc7-c6 Kh6-g7 84.Kh3-h4 Ra3-b3 85.Rc6-d6 Kg7-f7
86.Rd6-a6 Rb3-c3 87.Ra6-a7+ Kf7-e6 88.Ra7-a6+ Ke6-f7 89.Ra6-a7+) +0.36/27
2} 72. Kf2 {(72.Ke3-f2 Rb3-b4 73.Rd7-d6+ Kf6-f7 74.Kf2-e3 Rb4-e4+ 75.Ke3-f3
Re4-e1 76.Kf3-g2 Re1-e2+ 77.Kg2-f3 Re2-e6 78.Rd6-d7+ Re6-e7 79.Rd7-d8)
-1.00/14 2} Ke6 {(72. ... Kf6-e6 73.Rd7-c7 Rb3-d3 74.Rc7-g7 Ke6-f6
75.Rg7-b7 Rd3-a3 76.Rb7-b6+ Kf6-g7 77.Rb6-c6 Ra3-b3 78.Kf2-g2 Kg7-f7
79.Rc6-c7+ Kf7-f6 80.Rc7-c6+ Kf6-g7 81.Rc6-c7+ Kg7-h6 82.Kg2-h3 Rb3-a3
83.Rc7-c6 Kh6-g7 84.Kh3-h4 Ra3-b3 85.Rc6-d6 Kg7-f7 86.Rd6-a6 Rb3-c3
87.Ra6-a7+ Kf7-e6 88.Ra7-a6+ Ke6-f7 89.Ra6-a7+) +0.36/28 1} 73. Rg7
{(73.Rd7-g7 Rb3-b2+ 74.Kf2-f3 Ke6-f6 75.Rg7-d7 Rb2-b1 76.Rd7-d6+ Kf6-f7
77.Kf3-f2 Rb1-c1 78.Kf2-f3 Rc1-e1 79.Kf3-g2 Re1-e6 80.Rd6-d7+ Re6-e7)
-1.00/14 2} Rb2+ {(73. ... Rb3-b2+ 74.Kf2-e3 Ke6-f6 75.Rg7-c7 Rb2-b3+
76.Ke3-f2 Rb3-b6 77.Rc7-c8 Rb6-b2+ 78.Kf2-f3 Rb2-d2 79.Rc8-b8 Rd2-d7
80.Rb8-b6+ Kf6-f7 81.Kf3-g2 Rd7-d3 82.Kg2-f2 Rd3-d2+ 83.Kf2-f3 Rd2-d4
84.Kf3-f2 Rd4-d3 85.Kf2-g2 Rd3-a3 86.Rb6-c6 Ra3-e3 87.Rc6-b6 Re3-c3
88.Kg2-f2 Kf7-g7 89.Rb6-b7+ Kg7-h6 90.Rb7-b2 Rc3-d3 91.Rb2-b6 Kh6-g7
92.Kf2-g2 Rd3-c3 93.Rb6-a6 Rc3-e3 94.Kg2-h3 Re3-f3 95.Ra6-c6 Rf3-a3
96.Kh3-h4 Ra3-b3 97.Rc6-d6 Kg7-f7 98.Rd6-a6 Rb3-c3 99.Ra6-a7+ Kf7-e6
100.Ra7-a6+ Ke6-f7 101.Ra6-a7+) +0.36/29 2} 74. Kf3 {(74.Kf2-f3 Ke6-f6
75.Rg7-d7 Rb2-b1 76.Rd7-d6+ Kf6-f7 77.Kf3-e3 Rb1-c1 78.Ke3-f2 Rc1-c2+
79.Kf2-f3 Rc2-c4 80.Kf3-e3 Rc4-e4+ 81.Ke3-f3) -1.00/15 3} Kf6 {(74. ...
Ke6-f6 75.Rg7-d7 Rb2-b1 76.Rd7-c7 Rb1-b3+ 77.Kf3-g2 Rb3-d3 78.Rc7-c6+
Kf6-f7 79.Kg2-h3 Rd3-a3 80.Kh3-h4 Ra3-e3 81.Rc6-c7+ Kf7-f6 82.Rc7-c6+
Kf6-g7 83.Rc6-a6 Re3-b3 84.Ra6-a5 Kg7-h6 85.Ra5-a6 Rb3-c3 86.Kh4-h3 Rc3-e3
87.Ra6-b6 Kh6-g7 88.Rb6-b7+ Kg7-f6 89.Kh3-g2 Re3-e6 90.Kg2-h3 Re6-e2
91.Rb7-b8) +0.36/30 1} 75. Rd7 {(75.Rg7-d7 Rb2-b1 76.Rd7-d6+ Kf6-f7
77.Kf3-e3 Rb1-c1 78.Ke3-f2 Rc1-c2+) -1.00/14 2} Rb1 {(75. ... Rb2-b1
76.Rd7-c7 Rb1-b3+ 77.Kf3-g2 Rb3-d3 78.Rc7-c6+ Kf6-f7 79.Kg2-h3 Rd3-a3
80.Kh3-h4 Ra3-e3 81.Rc6-c7+ Kf7-f6 82.Rc7-c6+ Kf6-g7 83.Rc6-a6 Re3-b3
84.Ra6-a5 Kg7-h6 85.Ra5-a6 Rb3-c3 86.Kh4-h3 Rc3-e3 87.Ra6-b6 Kh6-g7
88.Rb6-b7+ Kg7-f6 89.Kh3-g2 Re3-a3 90.Rb7-b6+ Kf6-f7 91.Rb6-c6 Ra3-b3
92.Rc6-c7+ Kf7-f6 93.Rc7-c6+ Kf6-g7 94.Rc6-c7+ Kg7-h6 95.Kg2-h3 Rb3-a3
96.Rc7-c6 Kh6-g7 97.Kh3-h4 Ra3-b3 98.Rc6-c7+ Kg7-h6 99.Kh4-h3 Rb3-a3)
+0.36/30 2} 76. Rd6+ {(76.Rd7-d6+ Kf6-f7 77.Rd6-c6 Rb1-d1 78.Kf3-g2 Kf7-g7
79.Rc6-c7+ Kg7-h6 80.Rc7-h7+ Kh6xh7 81.Kg2-f3) -1.00/13 2} Kg7 {(76. ...
Kf6-g7 77.Rd6-c6 Rb1-b3+ 78.Kf3-g2 Kg7-f7 79.Rc6-c7+ Kf7-f6 80.Rc7-c6+
Kf6-g7 81.Rc6-c7+ Kg7-h6 82.Kg2-h3 Rb3-a3 83.Rc7-c6 Kh6-g7 84.Kh3-h4 Kg7-h6
85.Rc6-c8 Ra3-a1 86.Kh4-h3 Ra1-h1+ 87.Kh3-g2 Rh1-b1 88.Rc8-c6 Rb1-b3
89.Rc6-d6 Rb3-b2+ 90.Kg2-h3 Rb2-a2 91.Rd6-d3 Ra2-e2 92.Rd3-c3 Re2-e4
93.Rc3-c7 Re4-e6 94.Rc7-b7 Re6-e3 95.Rb7-c7) +0.36/30 1} 77. Rd7+
{(77.Rd6-d7+ Kg7-h6 78.Kf3-g2 Rb1-c1 79.Kg2-f2 Rc1-c2+ 80.Kf2-f3 Rc2-c3+
81.Kf3-g2 g6-g5) -1.00/13 1} Kh6 {(77. ... Kg7-h6 78.Rd7-d6 Rb1-b3+
79.Kf3-g2 Rb3-c3 80.Kg2-h3 Rc3-c2 81.Rd6-d3 Rc2-a2 82.Rd3-d7 Ra2-a3
83.Kh3-g2 Ra3-a1 84.Rd7-d6 Ra1-a2+ 85.Kg2-f3 Kh6-g7 86.Rd6-d7+ Kg7-g8
87.Rd7-c7 Ra2-b2 88.Rc7-c6 Rb2-b3+ 89.Kf3-g2 Kg8-h7 90.Rc6-c7+ Kh7-h6
91.Kg2-h3 Rb3-a3 92.Rc7-c6 Kh6-g7 93.Kh3-h4 Ra3-b3 94.Rc6-d6 Kg7-h6
95.Rd6-a6 Rb3-c3 96.Kh4-h3 Rc3-e3 97.Ra6-b6 Kh6-g7 98.Rb6-b7+ Kg7-f6
99.Kh3-g2 Re3-a3 100.Rb7-b6+ Kf6-f7 101.Rb6-c6 Ra3-e3 102.Rc6-b6 Re3-c3
103.Kg2-f2 Kf7-g7 104.Rb6-b7+ Kg7-h6) +0.36/31 2} 78. Rd8 {(78.Rd7-d8
Rb1-b3+ 79.Kf3-f2 Rb3-c3 80.Rd8-d4 Kh6-g7) -1.01/13 1} Rb7 {(78. ... Rb1-b7
79.Kf3-f2 Rb7-b3 80.Rd8-d6 Rb3-b4 81.Kf2-g2 Rb4-b2+ 82.Kg2-h3 Rb2-a2
83.Rd6-d3 Ra2-a6 84.Rd3-d7 Ra6-a3 85.Kh3-g2 Ra3-a1 86.Rd7-d6 Ra1-a2+
87.Kg2-f3 Kh6-g7 88.Rd6-d7+ Kg7-g8 89.Rd7-c7 Ra2-b2 90.Rc7-c6 Rb2-b3+
91.Kf3-g2 Kg8-h7 92.Rc6-c7+ Kh7-h6 93.Kg2-h3 Rb3-a3 94.Rc7-c6 Kh6-g7
95.Kh3-h4 Ra3-b3 96.Rc6-d6 Kg7-h6 97.Rd6-a6 Rb3-c3 98.Kh4-h3 Rc3-e3
99.Ra6-b6 Kh6-g7 100.Rb6-b7+ Kg7-f6 101.Kh3-g2 Re3-a3 102.Rb7-b6+ Kf6-f7
103.Rb6-c6 Ra3-e3 104.Rc6-b6 Re3-c3 105.Kg2-f2 Kf7-g7 106.Rb6-b7+ Kg7-h6)
+0.36/29 1} 79. Rc8 {(79.Rd8-c8 Rb7-b2 80.Rc8-h8+ Kh6-g7 81.Rh8-d8 Rb2-c2
82.Kf3-e3 Rc2-c4 83.Rd8-d7+ Kg7-h6 84.Rd7-d8 Rc4-c3+ 85.Ke3-f2 Rc3-c2+
86.Kf2-f3 Kh6-h7) -1.01/13 1} Rb3+ {(79. ... Rb7-b3+ 80.Kf3-g2 Rb3-b2+
81.Kg2-f3 Kh6-g7 82.Rc8-c6 Rb2-a2 83.Rc6-c7+ Kg7-h6 84.Rc7-c3 Ra2-d2
85.Rc3-e3 Rd2-b2 86.Re3-e6 Rb2-b3+ 87.Kf3-f2 Rb3-b1 88.Re6-c6 Rb1-b2+
89.Kf2-f3 Rb2-b3+ 90.Kf3-g2 Rb3-a3 91.Rc6-c7 Ra3-e3 92.Rc7-c6 Kh6-g7
93.Kg2-h3 Re3-b3 94.Kh3-h4 Kg7-h6 95.Rc6-a6 Rb3-c3 96.Kh4-h3 Rc3-e3
97.Ra6-b6 Kh6-g7 98.Rb6-b7+ Kg7-f6 99.Kh3-g2 Re3-a3 100.Rb7-b6+ Kf6-f7
101.Rb6-c6 Ra3-e3 102.Rc6-b6 Re3-c3 103.Kg2-f2 Kf7-g7 104.Rb6-b7+ Kg7-h6)
+0.36/30 2} 80. Kf2 {(80.Kf3-f2 Rb3-b2+ 81.Kf2-f3 Rb2-d2 82.Rc8-c7 Rd2-d3+
83.Kf3-f2 Rd3-d6 84.Rc7-e7 Rd6-a6) -1.01/14 1} Rb2+ {(80. ... Rb3-b2+
81.Kf2-f3 Kh6-g7 82.Rc8-c6 Rb2-a2 83.Rc6-c7+ Kg7-h6 84.Rc7-c3 Ra2-d2
85.Rc3-e3 Rd2-b2 86.Re3-e6 Rb2-b3+ 87.Kf3-f2 Rb3-b1 88.Re6-c6 Rb1-b2+
89.Kf2-f3 Rb2-b3+ 90.Kf3-g2 Rb3-a3 91.Rc6-c7 Ra3-e3 92.Rc7-c6 Kh6-g7
93.Kg2-h3 Re3-b3 94.Kh3-h4 Kg7-h6 95.Rc6-a6 Rb3-b2 96.Kh4-h3 Rb2-d2
97.Ra6-c6 Rd2-d3 98.Kh3-h4 Rd3-f3 99.Rc6-a6 Rf3-b3 100.Ra6-c6 Rb3-a3
101.Rc6-c8 Kh6-g7 102.Kh4-h3 Ra3-d3 103.Rc8-c7+ Kg7-f6 104.Rc7-c6+ Kf6-g7
105.Rc6-a6 Rd3-b3 106.Kh3-g2 Rb3-b2+ 107.Kg2-h3 Rb2-b1 108.Kh3-h4 Kg7-h6
109.Kh4-h3 Rb1-b3 110.Ra6-c6 Kh6-g7 111.Kh3-h4) +0.36/30 2} 81. Kf3
{(81.Kf2-f3 Rb2-d2 82.Rc8-g8 Rd2-d6) -1.01/14 1} Kg7 {(81. ... Kh6-g7
82.Rc8-c6 Rb2-a2 83.Rc6-c7+ Kg7-h6 84.Rc7-c3 Ra2-d2 85.Rc3-e3 Rd2-b2
86.Re3-e6 Rb2-b3+ 87.Kf3-f2 Rb3-b1 88.Re6-c6 Rb1-b2+ 89.Kf2-f3 Rb2-b3+
90.Kf3-g2 Rb3-a3 91.Rc6-c7 Ra3-e3 92.Rc7-c6 Kh6-g7 93.Kg2-h3 Re3-b3
94.Kh3-h4 Kg7-h6 95.Rc6-a6 Rb3-f3 96.Ra6-b6 Rf3-d3 97.Rb6-a6 Rd3-c3
98.Kh4-h3 Kh6-g7 99.Kh3-g2 Rc3-b3 100.Ra6-a7+ Kg7-h6 101.Ra7-a6 Rb3-b2+
102.Kg2-h3 Rb2-d2 103.Ra6-c6 Rd2-d3 104.Kh3-h4 Rd3-f3 105.Rc6-a6 Rf3-b3
106.Ra6-c6 Rb3-a3 107.Rc6-c8 Kh6-g7 108.Kh4-h3 Ra3-d3 109.Rc8-c7+ Kg7-f6
110.Rc7-c6+ Kf6-g7 111.Rc6-a6 Rd3-b3 112.Kh3-g2 Kg7-f7 113.Ra6-a7+ Kf7-f6
114.Kg2-h3 Rb3-b6 115.Kh3-h4 Rb6-c6 116.Kh4-h3 Rc6-c3 117.Ra7-a6+ Kf6-g7
118.Kh3-g2) +0.36/31 2} 82. Rc7+ {(82.Rc8-c7+ Kg7-f8 83.Rc7-c8+ Kf8-e7
84.Rc8-c7+ Ke7-e8 85.Rc7-c6 Rb2-b3+ 86.Kf3-g2 Ke8-f7 87.Rc6-c7+ Kf7-f6
88.Rc7-c6+ Kf6-g7) -0.83/14 1} Kg8 {(82. ... Kg7-g8 83.Rc7-c6 Rb2-b3+
84.Kf3-g2 Kg8-h7 85.Rc6-c7+ Kh7-h6 86.Kg2-h3 Rb3-a3 87.Rc7-c6 Kh6-g7
88.Kh3-h4 Ra3-d3 89.Rc6-c7+ Kg7-h6 90.Rc7-c6 Rd3-f3 91.Rc6-a6 Rf3-b3
92.Ra6-c6 Rb3-d3 93.Kh4-h3 Kh6-g7 94.Rc6-a6 Rd3-b3 95.Kh3-g2 Kg7-f7
96.Ra6-a7+ Kf7-f6 97.Ra7-a6+ Kf6-g7 98.Ra6-a7+ Kg7-h6 99.Ra7-a6 Rb3-b2+
100.Kg2-h3 Rb2-d2 101.Ra6-c6 Rd2-d3 102.Kh3-h4 Rd3-f3) +0.36/31 1} 83. Rc8+
{(83.Rc7-c8+ Kg8-f7 84.Rc8-c7+ Kf7-f8 85.Rc7-c8+) -0.83/14 1} Kf7 {(83. ...
Kg8-f7 84.Rc8-c7+ Kf7-e8 85.Rc7-c8+ Ke8-d7 86.Rc8-h8 Kd7-e7 87.Rh8-g8
Ke7-f7 88.Rg8-c8 Rb2-b3+ 89.Kf3-g2 Kf7-f6 90.Rc8-c6+ Kf6-g7 91.Rc6-c7+
Kg7-h6 92.Kg2-h3 Rb3-a3 93.Rc7-c6 Kh6-g7 94.Kh3-h4 Ra3-d3 95.Rc6-c7+ Kg7-h6
96.Rc7-c6 Rd3-b3 97.Rc6-a6 Kh6-h7 98.Kh4-h3 Kh7-g7 99.Kh3-g2 Kg7-f7
100.Ra6-a7+ Kf7-f6 101.Ra7-a6+ Kf6-g7 102.Ra6-a7+ Kg7-h6 103.Ra7-a6 Rb3-b2+
104.Kg2-h3 Rb2-d2 105.Ra6-c6 Rd2-d1 106.Rc6-c7 Rd1-h1+ 107.Kh3-g2 Rh1-b1
108.Rc7-c6 Rb1-b2+ 109.Kg2-f3 Rb2-b3+ 110.Kf3-g2 Rb3-a3 111.Rc6-c7 Ra3-e3
112.Rc7-c6 Kh6-g7 113.Kg2-h3 Re3-b3 114.Kh3-h4 Kg7-h6 115.Rc6-a6) +0.36/29
1} 84. Rc7+ {(84.Rc8-c7+ Kf7-f8 85.Rc7-c8+) -0.83/14 1} Ke8 {(84. ...
Kf7-e8 85.Rc7-c8+ Ke8-d7 86.Rc8-h8 Kd7-e7 87.Rh8-g8 Ke7-f7 88.Rg8-c8
Rb2-b3+ 89.Kf3-g2 Kf7-f6 90.Rc8-c6+ Kf6-g7 91.Rc6-c7+ Kg7-h6 92.Kg2-h3
Rb3-a3 93.Rc7-c6 Kh6-g7 94.Kh3-h4 Ra3-d3 95.Rc6-c7+ Kg7-h6 96.Rc7-c6 Rd3-f3
97.Rc6-a6 Rf3-b3 98.Ra6-c6 Rb3-d3 99.Kh4-h3 Kh6-g7 100.Rc6-a6 Rd3-b3
101.Kh3-g2 Kg7-f7 102.Ra6-a7+ Kf7-f6 103.Ra7-a6+ Kf6-g7 104.Ra6-a7+ Kg7-h6
105.Ra7-a6 Rb3-b2+ 106.Kg2-h3 Rb2-d2 107.Ra6-c6 Rd2-d1 108.Rc6-c7 Rd1-h1+
109.Kh3-g2 Rh1-b1 110.Rc7-c6 Rb1-b2+ 111.Kg2-f3 Rb2-b3+ 112.Kf3-g2 Rb3-a3
113.Rc6-c7 Ra3-e3 114.Rc7-c6 Kh6-g7 115.Kg2-h3 Re3-b3 116.Kh3-h4 Kg7-h6
117.Rc6-a6 Kh6-h7 118.Kh4-h3 Kh7-g7 119.Kh3-g2) +0.36/29 1} 85. Rc6
{(85.Rc7-c6 Rb2-b3+ 86.Kf3-g2 Ke8-f7 87.Rc6-c7+ Kf7-f6 88.Rc7-c6+ Kf6-g7
89.Rc6-c7+ Kg7-f8 90.Rc7-c6 Rb3-b2+ 91.Kg2-f3 Rb2-d2 92.Kf3-e3 Rd2-d1
93.Rc6xg6 Kf8-e7) -0.07/14 1} Rb3+ {(85. ... Rb2-b3+ 86.Kf3-g2 Ke8-f7
87.Rc6-c7+ Kf7-f6 88.Rc7-c6+ Kf6-g7 89.Rc6-c7+ Kg7-h6 90.Kg2-h3 Rb3-a3
91.Rc7-c6 Kh6-g7 92.Kh3-h4 Ra3-d3 93.Rc6-c7+ Kg7-h6 94.Rc7-c6 Rd3-f3
95.Rc6-a6 Rf3-b3 96.Ra6-c6 Rb3-d3 97.Kh4-h3 Kh6-g7 98.Rc6-a6 Rd3-f3
99.Kh3-h4 Kg7-f7 100.Ra6-a7+ Kf7-f6 101.Ra7-a6+ Kf6-g7 102.Ra6-c6 Rf3-b3
103.Rc6-c4 Rb3-d3) +0.36/30 2} 86. Kf2 {(86.Kf3-f2 h5-h4 87.g3xh4 Ke8-f7
88.Rc6-c7+ Kf7-f6 89.Rc7-c6+ Kf6-g7 90.Kf2-g2 Rb3-e3 91.Rc6-d6 Kg7-h6
92.Kg2-h2 Kh6-h5) -0.13/15 4} Kf7 {(86. ... Ke8-f7 87.Rc6-a6 Kf7-g7
88.Kf2-g2 Rb3-b2+ 89.Kg2-h3 Kg7-f7 90.Kh3-h4 Rb2-b3 91.Ra6-a7+ Kf7-f6
92.Kh4-h3 Rb3-b6 93.Kh3-h4 Rb6-e6 94.Ra7-c7 Re6-a6 95.Kh4-h3 Ra6-d6
96.Kh3-h4 Rd6-d3 97.Rc7-c6+ Kf6-g7 98.Rc6-c7+ Kg7-h6 99.Rc7-c6 Rd3-f3
100.Rc6-a6 Rf3-b3 101.Ra6-c6 Rb3-d3 102.Kh4-h3 Kh6-g7 103.Rc6-a6 Rd3-f3
104.Kh3-h4 Kg7-f7 105.Ra6-a7+ Kf7-f6 106.Ra7-a6+ Kf6-g7 107.Ra6-c6 Kg7-h6
108.Rc6-a6) +0.36/29 1} 87. Rc7+ {(87.Rc6-c7+ Kf7-e6 88.Rc7-c6+ Ke6-f7)
0.00/14 1} Kf8 {(87. ... Kf7-f8 88.Rc7-d7 Rb3-b2+ 89.Kf2-f3 Rb2-a2
90.Rd7-d6 Kf8-f7 91.Rd6-c6 Ra2-a3+ 92.Kf3-f2 Kf7-g7 93.Kf2-g2 Ra3-e3
94.Kg2-h3 Re3-b3 95.Kh3-h4 Kg7-h6 96.Rc6-a6 Rb3-f3 97.Ra6-c6 Rf3-d3
98.Kh4-h3 Kh6-g7 99.Rc6-a6 Rd3-b3 100.Kh3-g2 Rb3-b2+ 101.Kg2-h3 Rb2-b1
102.Ra6-a7+ Kg7-h6 103.Ra7-a6 Rb1-b2 104.Ra6-c6 Rb2-d2 105.Rc6-c7 Rd2-e2
106.Rc7-c6 Re2-a2 107.Rc6-f6 Ra2-a3 108.Rf6-c6 Kh6-g7 109.Kh3-h4 Ra3-d3
110.Rc6-c7+ Kg7-h6 111.Rc7-c6 Rd3-f3 112.Rc6-a6 Rf3-b3 113.Ra6-c6 Rb3-d3
114.Kh4-h3) +0.36/29 1} 88. Rc8+ {(88.Rc7-c8+ Kf8-e7 89.Rc8-c7+ Ke7-e6
90.Rc7-g7) 0.00/15 1} Kg7 {(88. ... Kf8-g7 89.Rc8-c7+ Kg7-g8 90.Rc7-c8+
Kg8-h7 91.Rc8-c7+ Kh7-h6 92.Rc7-c8) -0.02/27 1} 89. Rc7+ {(89.Rc8-c7+
Kg7-f6 90.Rc7-c6+ Kf6-f7) 0.00/15 1} Kf6 {(89. ... Kg7-f6 90.Rc7-d7 Kf6-e6
91.Rd7-c7) -0.02/38 1} 90. Rc6+ {(90.Rc7-c6+ Kf6-f7) 0.00/15 2} Kg7 {(90.
... Kf6-g7 91.Rc6-c7+ Kg7-g8 92.Rc7-c8+ Kg8-h7 93.Rc8-c7+ Kh7-h6 94.Rc7-c8)
-0.02/31 1} 91. Rc7+ {(91.Rc6-c7+) 0.00/16 2} Kh8 {(91. ... Kg7-h8
92.Rc7-c8+ Kh8-h7 93.Rc8-c7+ Kh7-h8 94.Rc7-c8+) -0.02/37 1} 92. Rc8+
{(92.Rc7-c8+ Kh8-g7) 0.00/16 1} Kh7 {(92. ... Kh8-h7 93.Rc8-c7+ Kh7-h8
94.Rc7-c8+ Kh8-h7) -0.02/36 1} 93. Rc7+ {(93.Rc8-c7+ Kh7-h6 94.Rc7-c8)
0.00/16 1} Kh8 {(93. ... Kh7-h8 94.Rc7-c8+ Kh8-h7 95.Rc8-c7+ Kh7-h8)
-0.02/70 1} 94. Rc8+ {(94.Rc7-c8+) 0.00/17 2} Kh7 {(94. ... Kh8-h7
95.Rc8-c7+ Kh7-h8 96.Rc7-c8+ Kh8-h7) -0.02/99 0} 95. Rc7+ {(95.Rc8-c7+)
0.00/17 1} Kh8 {(95. ... Kh7-h8 96.Rc7-c8+ Kh8-h7 97.Rc8-c7+ Kh7-h8)
-0.02/68 12 3-fold repetition} 1/2-1/2

BB+ wrote:From Division 2 of an on-going GM tournament:

Same game is being discussed at Talkchess http://www.talkchess.com/forum/viewtopic.php?t=37640,
but starting move 41.
Uri Blass argues this is won for Black, but computers are not convinced...
1R6/1P3pkp/1r4p1/8/1p6/5P2/4K1PP/8 w - - 0 41

The game was played out using much weaker 32-bit single core vs Houdini on quad core.

The main problem with comp-comp "roll-outs" is that the whole issue is "knowledge-based" (Black needs to find a plan), and so the extra depth might not be that useful. OTOH, as the endgame manuals will point out, simply having a plan and actually executing it are two different things. This one has a number of tricks, and White has multiple ways of achieving a draw when down 2 (or even 3) pawns. The main theoretical "fact" to know is that Rook+f+h versus Rook is a book draw in many cases (certainly if the White King gets to g1). Navara gave a 40-minute "master-class" impromptu presentation about it, though the analysts will still pick apart where theory and practise diverged.
http://www.chessvibes.com/reports/rook- ... -wojtaszek

For a Wijk aan Zee example from 3 years back, see Kramnik-Aronian (Black blundered on move 103): http://www.chessgames.com/perl/chessgame?gid=1482242

BB+ wrote:

The game was played out using much weaker 32-bit single core vs Houdini on quad core.

The main problem with comp-comp "roll-outs" is that the whole issue is "knowledge-based" (Black needs to find a plan), and so the extra depth might not be that useful. OTOH, as the endgame manuals will point out, simply having a plan and actually executing it are two different things. This one has a number of tricks, and White has multiple ways of achieving a draw when down 2 (or even 3) pawns. The main theoretical "fact" to know is that Rook+f+h versus Rook is a book draw in many cases (certainly if the White King gets to g1). Navara gave a 40-minute "master-class" impromptu presentation about it, though the analysts will still pick apart where theory and practise diverged.
http://www.chessvibes.com/reports/rook- ... -wojtaszek

For a Wijk aan Zee example from 3 years back, see Kramnik-Aronian (Black blundered on move 103): http://www.chessgames.com/perl/chessgame?gid=1482242

I saw that article on Chessvibe but didn't really pay much attention, so now I will schedule some time and watch the lecture. Looking at the position from your 1st post, Black has a slight advantage, but to me not enough for a win.

Incidentally, while looking at a side-line from HIARCS-Rybka, the main variation led to Black being up two pawns, but a drawn Rook + a-pawn + c-pawn versus Rook position resulted. Not that TCEC uses 6 piece tablebases though...

Incidentally, while looking at a side-line from HIARCS-Rybka

As the game progressed, more and more lines were descending into such a "draw well" (of R+ac versus R). But I don't think either had "special knowledge" of this endgame, so if a draw had occurred in this manner, it would likely have been an accident.

Well, now it's transformed into something where White could get a fortress draw, I think:
[White "HIARCS"][Black "Rybka"][FEN "8/k7/2p1N3/p6p/P7/1R3rP1/2p1K2P/8 w - - 0 52"] 52. Rxf3 c1=Q 53. Nd4 Qc4+ 54. Rd3 Qxa4 55. Kd2 c5 56. Nc2 Qe4 57. Ra3 a4 58. Kc3 *The starting position is that of the game, the line is my PV. Is it obvious how Black can make progress? No targets for the Queen (attacking h2 just leads to Ph4, with the g3 pawn protected by the Rook), both passers blockaded, if the King supports the pawn, both the Rook/Knight guard a3, and the c-pawn remains blocked... Though again, it's not like engines know these things.