Wednesday, March 16, 2011

Indecisions, indecisions . . .

Back in January I wrote a post about getting into time-trouble, and afterwards I decided to manage my clock more circumspectly. The result? Less time-trouble, but terrible results: my average grade for the season before the decision was 207, afterwards 188. For our international readers, that's about the same as a loss of 150 Elo points in form.

Brilliant! Now, yes, it's only been half a dozen or so games since The Decision, and since 207 represents an over-performance maybe there's just some averaging going on; on the other hand, when I look over my games I start scratching my head, wondering what was I thinking. Or rather, what wasn't I thinking, and how did I miss that.

But judge for yourself. Here are three examples given in the form of puzzles, all taken from a recent game (the one game which I actually managed to win, incidentally!) Solutions follow after the jump. I had the black pieces.

Position 1:


A who's-move-ordering-who open Sicilian, and I've just played 9... b5-b4. The position is known to theory and my opponent played 10.Nc2, one of two normal moves. But the other I had not remotely considered. Can you see it?


Position 2: 


White's sacrificed a pawn for a bit of pressure on the h1 to a8 diagonal, and the position is quite complicated too. Now, I was pretty convinced that after the forced sequence 19...Nxd4 20. Bxa8 Nf5 21.Rxf5 exf5 22.Bd5+ the position would be close to equal, with white's better pieces compensating for his pawn minus. But I decided I wanted more and played 19...Qd7 instead. Had I analyzed the position correctly?

Position 3: 



Black's extra pawn is looking better and better, and I've just played 22...Nf3+ to simplify matters. 23.Qxf3 loses, 23.gxf3 is ugly, and I wasn't sure which of the other two captures to worry about most. What should have I worried about most?

Solutions after the jump!

Solutions



Position 1. The tricksy 10.Qa4 is the other theoretical possibility here. If black is prepared for it he should be OK. Black was not prepared for it.

Position 2. After 19...Qd7, the simple and thematic Sicilian move 20.Nxe6! is close to crushing. The knight is immune because after 20...Qxe6 21.Bd5 white has won the black Queen. My analysis of 19...Nxd4 was not too bad; the computer thinks black is better by about half a pawn after the forced sequence.

Position 3. The computer is pretty convinced the amusing 23.Kh1 is white's best attempt to stay in the game here. Not even a blip on my radar.

1 comment:

Anonymous said...

The first two are, as you say, fairly normal Sicilian ideas. If you wish to save time on the clock, you have to be able to see the tricks almost as part of the positional assessment. Obviously you can find these moves by analysis or tree searching but at G/90 you need the time for more difficult stuff. I don't know that it matters that you missed Kh1, as Black is now well on top presumably and does a grovel like Kh1 really change much? Still you are more likely to spot it with more time.

RdC