30 September 2015

Child's Play

A two pawn advantage in a rook ending should be decisive. Indeed, I won easily with such an advantage last night in a three minute blitz game. The win seemed child's play.

A few minutes of postgame analysis this morning revealed another story. I made a fatal blunder and won because my opponent missed a critical opportunity.

Black to move
After 46.Ke2
46...g5 47.Kf3 gxf4

47...Kg6 is better. 48.Rxg2 Rxg2 49.Kxg2 g4 and the pawn ending is an elementary win for Black.

48.exf4 e5 49.fxe5+ Kxe5 50.Re1

Black to move


It was necessary to move the king to the d-file. 50...Kd4 was best.


51.Kf2 Rg5 (51...f4 52.Rg1=) 52.Rb1 Rg8 and the computer thinks that Black has a slight edge. Accurate play by White should hold the draw.

White to move
Analysis Diagram after 52...Rg8

The Drawing Method

From the analysis diagram, I played out the position against Stockfish. Perhaps the drawing method is not as simple as the win became in the game, but it requires only application of some elementary techniques.

Stripes,James -- Stockfish 6 64

53.Ra1 Ke5 54.Ra5+

Side checks are the key drawing method until White's king gets too close to the rook, then either restraining the advance of the f-pawn or rear-checks become necessary. Although not a textbook Philidor position, the drawing method follows the same idea.

54...Kd6 55.Ra1 Rg7 56.Ra6+ Kc5 57.Ra5+ Kb4 58.Ra1 Kc3

White to move


59.Ra3+ fails to Kb2.
59.Rg1 fails to Kd2.
59.Rd1 fails to f4.

59...f4 60.Ra4 Rg4 

60...f3 is met by 61.Rf4

61.Ra3+ Kd4 62.Ra4+ Kc5 63.Ra5+ Kb4

White to move


White now prevents f3.

64...Ka3 65.Rf8 Kb3 66.Rf7 Kc2 67.Rf8 Kd3 

White to move


With the White king able to support f3, he must be harassed endlessly with checks from the rear.

68...Ke2 69.Re8+ Kd1 70.Rd8+ Ke1 71.Re8+ Kd2 72.Rd8+ Ke3 73.Re8+ Kf3

White to move


Preparing to resume checks from the side.

74...Ke4 75.Ra4+ Kf5 76.Ra5+ Ke6 77.Ra6+ Kd5 78.Ra5+ Kc6 79.Rf5

Again restraining the f-pawn.

79...Kd6 80.Rf8 Ke6 81.Re8+ Kf6 82.Rf8+ Kg7 

White to move

83.Rf5 Kg6 84.Rf8 f3 

The computer gives up.

85.Rxf3 Kh6 86.Rf2 Rg5 87.Rxg2 Rc5 88.Rf2 Ra5 ½–½

The Actual Game

After 51.Rg1?? in the game, we reached this position.

Black to move


This was Black's only winning move, but is was simple to find and I played it automatically.

52.Kf2 f4 53.Kf3 Rg3+ 54.Kf2 Kg4 55.Re1

Black to move

Now, it is time to convert the rook ending into an elementary pawn ending.

55...g1Q+ 56.Rxg1 Rxg1 57.Kxg1 Kg3 58.Kf1 Kf3 59.Ke1 Kg2 and White resigned.

No comments:

Post a Comment