Rook endgame: Wojtaszek-Navara

[Albert Silver]

It is rather interesting to see the difficulty that some endgame evaluations still pose, even without requiring special shots to be seen. In today's game between Wojtaszek-Navara, the endgame that ensued was only understood to be lost much much later than strong human players.

At this point:

[D]1R6/1P3pkp/1r4p1/8/1p6/5P2/4K1PP/8 w - - 0 41

It was quite clear white was dead lost, but the engines really needed to calculate it to death.

[Kurt Utzinger]

It is rather interesting to see the difficulty that some endgame evaluations still pose, even without requiring special shots to be seen. In today's game between Wojtaszek-Navara, the endgame that ensued was only understood to be lost much much later than strong human players.

At this point:

[D]1R6/1P3pkp/1r4p1/8/1p6/5P2/4K1PP/8 w - - 0 41

It was quite clear white was dead lost, but the engines really needed to calculate it to death.

Hi Albert
This is a very tricky endgame for engines since in some lines Black cannot win in spite of two plus pawns. Therefore I fully understand that engines have no chance for a correct evaluation in this position. Below the game in PGN.
Regards
Kurt


[Event "73rd Tata Steel GMB"]
[Site "Wijk aan Zee NED"]
[Date "2011.01.15"]
[Round "1"]
[White "Wojtaszek, R."]
[Black "Navara, D."]
[WhiteElo "2726"]
[BlackElo "2708"]
[ECO "D90"]
[Result "0-1"]

1. d4 Nf6 2. c4 g6 3. Nc3 d5 4. Nf3 Bg7 5. Qa4+ Nc6 6. Bg5
Ne4 7. cxd5 Nxc3 8. bxc3 Qxd5 9. e3 O-O 10. Qb5 Be6 11. Be2
Qxb5 12. Bxb5 Rfe8 13. Nd2 a6 14. Bd3 Na5 15. Ke2 c5 16. a4
cxd4 17. cxd4 Bd5 18. f3 e5 19. dxe5 Bxe5 20. Rac1 Bc6
21. Nc4 Nb3 22. Rb1 Nc5 23. Nb6 Rab8 24. Bc2 Bc7 25. a5
Bb5+ 26. Kf2 Bxb6 27. axb6 Rbc8 28. Bf4 Bd3 29. Bxd3 Nxd3+
30. Kg3 Nxf4 31. Kxf4 Rc6 32. Rhd1 Rf6+ 33. Kg3 Rxe3
34. Rd7 Re5 35. Rxb7 Rb5 36. Rxb5 axb5 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 (51. Re2 Rb3 52. Rxb2
Rxg3 53. Kc2 Rg4 54. Rb4 Rxh4 55. Kd3 Kg7 56. Ke3 Rg4
57. Rb8 h4 58. Kf3 Rg3+ (58... g5 59. fxg5 h3 60. Rb1 Kg6
61. Rh1 Rh4 62. Kg3 Kxg5 63. Kh2 {draw}) 59. Kf2 Ra3
60. Kg2 Ra4 61. Kf3 Ra3+ 62. Kg2 h3+ 63. Kh2 Rf3 64. Rb4
Kh6 65. Ra4 Kh5 66. Ra8 Rxf4 67. Kxh3) 51... Ke6 52. Rd3
Ke7 53. Ra3 Kd7 54. Ra7+ Ke6 55. Ra3 Kd5 56. Rc3 Kd4
57. Ra3 Kc4 58. Ra4+ Kd3 0-1

[Kurt Utzinger]

It is rather interesting to see the difficulty that some endgame evaluations still pose, even without requiring special shots to be seen. In today's game between Wojtaszek-Navara, the endgame that ensued was only understood to be lost much much later than strong human players.

At this point:

[D]1R6/1P3pkp/1r4p1/8/1p6/5P2/4K1PP/8 w - - 0 41

It was quite clear white was dead lost, but the engines really needed to calculate it to death.

Hi Albert
This is a very tricky endgame for engines since in some lines Black cannot win in spite of two plus pawns. Therefore I fully understand that engines have no chance for a correct evaluation in this position. Below the game in PGN.
Regards
Kurt


[Event "73rd Tata Steel GMB"]
[Site "Wijk aan Zee NED"]
[Date "2011.01.15"]
[Round "1"]
[White "Wojtaszek, R."]
[Black "Navara, D."]
[WhiteElo "2726"]
[BlackElo "2708"]
[ECO "D90"]
[Result "0-1"]

1. d4 Nf6 2. c4 g6 3. Nc3 d5 4. Nf3 Bg7 5. Qa4+ Nc6 6. Bg5
Ne4 7. cxd5 Nxc3 8. bxc3 Qxd5 9. e3 O-O 10. Qb5 Be6 11. Be2
Qxb5 12. Bxb5 Rfe8 13. Nd2 a6 14. Bd3 Na5 15. Ke2 c5 16. a4
cxd4 17. cxd4 Bd5 18. f3 e5 19. dxe5 Bxe5 20. Rac1 Bc6
21. Nc4 Nb3 22. Rb1 Nc5 23. Nb6 Rab8 24. Bc2 Bc7 25. a5
Bb5+ 26. Kf2 Bxb6 27. axb6 Rbc8 28. Bf4 Bd3 29. Bxd3 Nxd3+
30. Kg3 Nxf4 31. Kxf4 Rc6 32. Rhd1 Rf6+ 33. Kg3 Rxe3
34. Rd7 Re5 35. Rxb7 Rb5 36. Rxb5 axb5 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 (51. Re2 Rb3 52. Rxb2
Rxg3 53. Kc2 Rg4 54. Rb4 Rxh4 55. Kd3 Kg7 56. Ke3 Rg4
57. Rb8 h4 58. Kf3 Rg3+ (58... g5 59. fxg5 h3 60. Rb1 Kg6
61. Rh1 Rh4 62. Kg3 Kxg5 63. Kh2 {draw}) 59. Kf2 Ra3
60. Kg2 Ra4 61. Kf3 Ra3+ 62. Kg2 h3+ 63. Kh2 Rf3 64. Rb4
Kh6 65. Ra4 Kh5 66. Ra8 Rxf4 67. Kxh3) 51... Ke6 52. Rd3
Ke7 53. Ra3 Kd7 54. Ra7+ Ke6 55. Ra3 Kd5 56. Rc3 Kd4
57. Ra3 Kc4 58. Ra4+ Kd3 0-1

[Karlo Bala]

It is rather interesting to see the difficulty that some endgame evaluations still pose, even without requiring special shots to be seen. In today's game between Wojtaszek-Navara, the endgame that ensued was only understood to be lost much much later than strong human players.

At this point:

[D]1R6/1P3pkp/1r4p1/8/1p6/5P2/4K1PP/8 w - - 0 41

It was quite clear white was dead lost, but the engines really needed to calculate it to death.

I'm not sure that white was a dead lost. Can you post some moves or plan for black?

[Uri Blass]

I did not do a lot of analysis but
the plan for black seems simple for me.
1)put the black pawn at b2 and force the white king to go to b1
2)make waiting move until white has no pawn moves and has to move the rook so black won a pawn.
3)win the rook endgame with pawn up that should be easy when you have a rook behind the pawn because you progress with your king and support the pawns and the opponent king cannot defend because if the opponent is going to capture the pawn you trade rooks and win the pawn endgame and if the and if the opponent try to move the king and block with the rook you sacrifice the pawn by promoting it and again trade rooks and win the pawn endgame.

White may try to defend by sacrificing the pawn and blocking the black pawn with the rook but I believe that it also wins for black.

[Albert Silver]

I did not do a lot of analysis but
the plan for black seems simple for me.
1)put the black pawn at b2 and force the white king to go to b1
2)make waiting move until white has no pawn moves and has to move the rook so black won a pawn.
3)win the rook endgame with pawn up that should be easy when you have a rook behind the pawn because you progress with your king and support the pawns and the opponent king cannot defend because if the opponent is going to capture the pawn you trade rooks and win the pawn endgame and if the and if the opponent try to move the king and block with the rook you sacrifice the pawn by promoting it and again trade rooks and win the pawn endgame.

White may try to defend by sacrificing the pawn and blocking the black pawn with the rook but I believe that it also wins for black.

That pretty much sums it up.

[ernest]

That pretty much sums it up.

Well, computers don't have much of a clue...

Analysis by Houdini 1.5a w32 gtb:
1.Kd2 b3 2.Kc1 b2+ 3.Kb1 h5 4.Rc8 Rxb7 5.Rc2 Rb4 6.Rxb2 Rc4 7.Rc2 Rh4 8.h3 Rd4 9.Kc1 Kf6 10.Rc5 Ra4 11.Kb2 h4 12.Rb5 Ra8 13.Rb4 Re8 14.Rf4+ Kg7 15.Rg4 Re2+ 16.Kc3 f5 17.Rxh4 Rxg2 18.Rb4
= (-0.09) Depth: 30/53 00:13:29 1606mN, tb=1184

Zappa Mexico II is a little more optimistic, but not much
Analysis by Zappa Mexico II:
1.Kd2 b3 2.Kc1 b2+ 3.Kb1 Kh6 4.f4 Kg7 5.g3 Kf6 6.g4 Rb4 7.h3 Rb6 8.h4 Rb3 9.Kc2
-/+ (-1.06) Depth: 18/51 00:00:29 32611kN, tb=1
..............
1.Kd2 b3 2.Kc1 b2+ 3.Kb1 Kh6 4.h4 f5 5.g4 fxg4 6.fxg4 Rb3 7.Rc8 Rxb7 8.Rc4 Kg7 9.Rc8 Kf6 10.Rc5 Ke6 11.h5 Kf6 12.Rd5 Kg7 13.Re5
-/+ (-1.21) Depth: 26/71 02:08:47 8160mN, tb=20972

[Graham Banks]

I did not do a lot of analysis but
the plan for black seems simple for me.
1)put the black pawn at b2 and force the white king to go to b1
2)make waiting move until white has no pawn moves and has to move the rook so black won a pawn.
3)win the rook endgame with pawn up that should be easy when you have a rook behind the pawn because you progress with your king and support the pawns and the opponent king cannot defend because if the opponent is going to capture the pawn you trade rooks and win the pawn endgame and if the and if the opponent try to move the king and block with the rook you sacrifice the pawn by promoting it and again trade rooks and win the pawn endgame.

White may try to defend by sacrificing the pawn and blocking the black pawn with the rook but I believe that it also wins for black.

Very nice explanation Uri.

[ernest]

I did not do a lot of analysis but
the plan for black seems simple for me.
1)put the black pawn at b2 and force the white king to go to b1
2)make waiting move until white has no pawn moves and has to move the rook so black won a pawn.
3)win the rook endgame with pawn up that should be easy when you have a rook behind the pawn because you progress with your king and support the pawns and the opponent king cannot defend because if the opponent is going to capture the pawn you trade rooks and win the pawn endgame and if the and if the opponent try to move the king and block with the rook you sacrifice the pawn by promoting it and again trade rooks and win the pawn endgame.

White may try to defend by sacrificing the pawn and blocking the black pawn with the rook but I believe that it also wins for black.

Well now, after
1. Kd2 b3 2. Kc1 b2+ 3. Kb1 Kh6 4. h4 f5 5. g4 fxg4 6. fxg4 Rb3 7. Rc8 Rxb7 8.Rc4 Kg7 9. g5 h5
we have attained stage 3
[D]8/1r4k1/6p1/6Pp/2R4P/8/1p6/1K6 w - h6 0 10
Is this so straightforward to win for Black?
Computers don't think so...

[Karlo Bala]

That pretty much sums it up.

Well, computers don't have much of a clue...

Analysis by Houdini 1.5a w32 gtb:
1.Kd2 b3 2.Kc1 b2+ 3.Kb1 h5 4.Rc8 Rxb7 5.Rc2 Rb4 6.Rxb2 Rc4 7.Rc2 Rh4 8.h3 Rd4 9.Kc1 Kf6 10.Rc5 Ra4 11.Kb2 h4 12.Rb5 Ra8 13.Rb4 Re8 14.Rf4+ Kg7 15.Rg4 Re2+ 16.Kc3 f5 17.Rxh4 Rxg2 18.Rb4
= (-0.09) Depth: 30/53 00:13:29 1606mN, tb=1184

After 6. Rxb2 it is a draw.

Zappa Mexico II is a little more optimistic, but not much
Analysis by Zappa Mexico II:
1.Kd2 b3 2.Kc1 b2+ 3.Kb1 Kh6 4.f4 Kg7 5.g3 Kf6 6.g4 Rb4 7.h3 Rb6 8.h4 Rb3 9.Kc2
-/+ (-1.06) Depth: 18/51 00:00:29 32611kN, tb=1

After 6. Rh8 looks like white is holding position