19 December 2013

An Active King

Tarrasch -- Schlechter, Monte Carlo 1902 has occupied my study time this past week (view at chessgames.com). It begins as a mainline closed Spanish. It appears that Schlechter made a series of small errors that led to a clearly worse position, but Tarrasch still needed to demonstrate some fine endgame technique to secure the win.

White to move
After 49...Ke7
50.Ra4 appears to give White a decisive advantage.

50...Rxa4 51.Bxa4 Kd8 52.Kc2 Kc7 53.Kb2

Black to move

White has a clear plan to penetrate with his king and start picking off vulnerable pawns. However, this process might take many moves and Black is not without resources to snatch a draw from the position.

Schlechter's 53...Nc5 seems to me to render White's job easier. In the game, Tarrasch demonstrated how the resulting passed pawn could be pushed and sacrificed to force an exchange into a pawn ending.


Practicing Technique

Starting from the position in the first diagram above, I played out the game against Fritz 11. Although not my strongest engine, it is adequate to the task. My first few efforts demonstrated a want of proper technique in my set of skills. I had to concede a draw on several occasions. After several efforts over three days, I was able to win against the engine.

My tests suggest that 53...Nc5 was not the critical error, but that Black is already lost at this point.

Stripes -- Fritz 11

50.Ra4 Rxa4 51.Bxa4 Bb7 52.Kc2 Kd8 53.Kb2 Kc8 54.Ka3 Nb8 55.Kb4 Na6+ 56.Ka5 Nc7

White to move

57.Kb6? would stumble into a tactic. 57...Bxd5 58.exd5 Nxd5+ and White will be happy with a draw.

57.Bf2 stepping out of the fork.

57...Nxd5!?

I was stunned when the computer played this move, but it took several efforts for me to hone the skills necessary to win with the extra piece.

58.exd5 Bxd5 59.Bd1 Kc7 60.Kb5 Kd7

White to move

Wednesday Evening I played this position to a successful conclusion.

61.Bb6 Ke8 62.Be3 Kd7 63.f4 gxf4 64.gxf4 Ke7 65.Be2 Be4 66.Bxc4 exf4 67.Bxf4 Bg2 68.Be2 Kd7

White to move

69.Kc4

I did not find the plan immediately.

69...Bc6 70.Bd3 Ke7 71.Kd4 Bb7 72.Be4 Ba6

White to move

73.Bf5

I tried 73.c4 and that game ended with insufficient material on move 105. So, I backed up and tried 73.Bf5 with success.

73...Bb7 74.Kc4 Bc6 75.Kb4 Bd5 76.Kb5

Now, my king knows his role.

76...Bf3 77.Kb6 Bd5 78.Kc7 Bc4

White to move

79.Bxd6+

After winning this pawn, my king then maneuvered its way to g7 to win the other pawn, which I was able to capture on move 99.

In the morning, feeling a sense of success after several false starts, I set out to win the game more efficiently from move 61. Fritz varied its defense and I needed a new winning plan.

Thursday Morning

61.Be3 Ke6 62.Be2

Threatening to force the exchange of bishops.

62...Ke7 63.f4 gxf4 64.gxf4 exf4 65.Bxf4 Kd7 66.Bxc4 Bf3

White to move

67.g5

Stockfish 4 suggested during postgame analysis that I could exchange the g-pawn for White's d-pawn. 67.Kb6 Bxg4 68.Bb5+ Ke6 69.Kc7 Kf5 70.Bxd6 Bd1 71.Bd7+ Ke4 72.c4! and the c-pawn starts to roll.

67...fxg5 Bxg5 68.Bxg5 Be4 69.Be2 Kc7 70.Be3 Bg2 71.Bb6+

I suspect that I was pursuing another phantom at this stage.

71...Kb7 72.Bc4 Bf3 73.Be6 Bc6+ 74.Ka5 Be4 75.Be3 Kc6 76.Kb4 d5

White to move

Not very many years ago, I would give up in such positions and concede a draw. But there is a simple winning plan: the White king with the assistance of his bishops can force his way behind the Black pawn.

77.Bd4 Kd6 78.Bf7 Bf3 79.Kb5 Be2+ 80.Kb6 Bf3 81.Bc5+ Ke5 82.Bg6 Kf6

White to move

I thought to myself that Fritz was cooperating a bit. Even so, I had plans of Kc7 to prevent Kd6, then Bd4 to blockade the pawn, and after Kc6, I would threaten Bg8+. So, perhaps, chasing the bishop makes sense for Black.

83.Bh7 Kg7 84.Bc2 Kf7 85.Bb3 Ke6 86.Kc6 Bg2 87.Bd4 Be4

White to move

88.Bd1 Bh1 89.Bg4+ Ke7 90.Bf5 Bf3 91.Bh7 Kf7 92.Kd6

Now that my king occupies the critical square, the rest should be easy.

92...Bg4 93.Bc2 Ke8 94.Bb3 Kf7 95.Bxd5+

Black to move

95...Kg6 96.c4

This time I accepted the machine's resignation, satisfied that I had no more to learn from the position.




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