In my recent article on Obstruction and Paralysis I set three examples for readers to solve. The first was a two-mover by Michael McDowell, which he sent as a counterexample of my statement that it is not possible to show the theme of obstruction in a two-mover. Let us first see the solution:
Michael accompanied this problem with a note: “An interference prevents a piece reaching a square beyond the interference square [in this case f3], so it seems to me that 1...Kf3 is an obstruction [of the bishop].” In other words, the king is occupying a square which the bishop could otherwise occupy to ward off the check from the rook.
This might turn out to be a tricky philosophical issue, but it seems to me
that, if the king is in check on f3 there is no question of interposing a piece
on f3; therefore, the king is not obstructing the bishop from interposing between
it and the rook. I do understand that Michael is drawing a parallel between
interference by the king, which can be shown in a two-mover,
and obstruction by the king. However, I think that parallel
is false. But I could be wrong and anyone wishing to enter the fray on this
discussion is welcome to do so!
This closes my brief survey of Obstruction and Paralysis. Next time we’ll start to look at one of the most fertile areas of problemdom: pins.
Any queries or constructive comments can be addressed to the author at david.friedgood@gmail.com.
Copyright in this article David Friedgood 2012/ChessBase
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British Chess Problem Society (BCPS), founded in 1918, is the world's
oldest chess problem society. It exists to promote the knowledge and enjoyment
of chess compositions, and membership is open to chess enthusiasts in all countries.
The Society produces two bi-monthly magazines, The Problemist and The Problemist Supplement (the latter catering for beginners), which are issued to all members. Composers from all over the world send their problems and studies to compete in the tourneys run by the society.
The BCPS also organises the annual British Chess Solving Championship, and selects the Great Britain squad for the World Chess Solving Championship. The Society holds an annual residential weekend, with a full programme of solving and composing tourneys and lectures; this event attracts an international participation. Members are also entitled to use the resources of the BCPS library, and the Society book service, which can provide new and second-hand publications.
