Sunday, October 14, 2007

Interference



The first diagram shows a position from the game Janowski-Schallop, Nuremburg 1896. White has active pieces but seems to be losing the initiative because of the counterattack on his rook. He solves that problem with a surprise move:

1.Bd5!
An interference sacrifice, closing off the defence of c6 by the Black queen. If Black plays 1...Qh3 then White can simply win a rook with 2.Bxc6+.
1...exd5 2.Qxc6+ Kd8 3.Qxa8+ Kd7 4.Qb7+ Ke6
Other moves are obviously no better. Black is continuing out of pure inertia.
5.Qc6+ Bd6 6.Bf4!
Black resigned. He is mated after 6...Qxh1+ 7.Kd2 Qxa1 8.Qxd6+ Kf5 9.Qe5+ Kg6 10.Qg5.

The second diagram shows a position from the game Scoones-Gregg, Portland 1976. My opponent has sacrificed a piece for some counterplay against my king, which is more annoying than it looks because of my passive bishop on g3. After studying the position for a short time I saw an opportunity to break Black's resistance by sacrificing the bishop in unusual fashion:

1.Be5! dxe5
If 1...Bxe5 then 2.Qf8+ Kd7 3.Bf5 mate. The strongest line of resistance is 1...Qa3+ 2.Kd1 dxe5 3.Qxg7 (not 3.Qg8+? Qf8) 3...Bxf3 4.gxf3 Qd6 but after 5.Ke2 the win is not in any doubt.
2.Qg8+ Kd7 3.Qxg7+ Kd6 4.Qxh6+ Kc5 5.Qxg5
Black's position is hopeless and he resigned after a few more moves.

Janowski's combination must be valued more highly than my mundane effort, for two main reasons:

1. In Janowski's game, the sacrifice is the only way to win or even avoid serious disadvantage;
2. In my game, the sacrifice is effective but not strictly necessary. White is already a piece ahead and has an alternative winning line that starts with 1.Qg8+ Kd7 2.Bf5+.

I do not believe I had seen the Janowski combination when my game was played. But I know I had seen something like it. One must study the classics!

1 comment:

Ryan Emmett said...

Interesting combinations!

Interference sacrifices are difficult to spot, but having seen Janowsky's great move and your own inventive continuation, that might help me notice such opportunities in my own games.

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Port Coquitlam, British Columbia, Canada
National master (Canada) since 1984. B.C. Champion 1977 and 1984. Runner-up 1991 and 2002. B.C. Open Champion 1972 and 1982. B.C. U/14 Champion 1964-65-66. Mikhail Botvinnik once wrote that publishing your analytical work forces you to be accurate because it exposes you to criticism. Hence this blog.