Chess: Solving problems about problems

MOST problems pit a white army against a hugely outnumbered black force. Indeed the obvious unfairness of it is a common excuse for players who refuse to become entangled with problems. Here is an offering to overcome those objections. Composed by Walter Speckman, it is a witty exception to the general rule. White, with only a bishop against bishop knight and three pawns, is to play and mate in seven moves.

The idea is clear: Black must be induced to advance his pawn to a2, after which the white bishop will be able to mate. First, however, White has to kill off the knight and capture or immobilise the d-pawn.

White must start with a bishop move and 1. Bf3 is the obvious candidate. It prevents Nb7 or Nc6, and also ensures that Ne6 or Nf7 lose the kight to Be4+ followed by Bd5+.

So Black's best is 1 . . . Ka2 when White must play 2. Bd5+ (to prevent the b-pawn promoting) Kb1 and now White must contrive to lose a move. So the solution continues 3. Kd1] when Black must move his knight and lose it. So play goes on 3 . . . Nb7 (or anywhere else) 4. Bxb7 Ka2 5. Bd5+ Kb1 6. Kd2] and finally Black has no choice but self-interment with 6 . . . a2, allowing mate with 7. Be4. A simple task, but a pleasing triumph for minimal force against assorted junk.