AN AMAZING DILEMMA.
(
The Guarded Chessboard)
In a game of chess between Mr. Black and Mr. White, Black was in
difficulties, and as usual was obliged to catch a train. So he proposed
that White should complete the game in his absence on condition that no
moves whatever should be made for Black, but only with the White pieces.
Mr. White accepted, but to his dismay found it utterly impossible to win
the game under such conditions. Try as he would, he could not checkmate
his opponent. On which square did Mr. Black leave his king? The other
pieces are in their proper positions in the diagram. White may leave
Black in check as often as he likes, for it makes no difference, as he
can never arrive at a checkmate position.
Answer:
Mr Black left his king on his queen's knight's 7th, and no matter what
piece White chooses for his pawn, Black cannot be checkmated. As we
said, the Black king takes no notice of checks and never moves. White
may queen his pawn, capture the Black rook, and bring his three pieces
up to the attack, but mate is quite impossible. The Black king cannot be
left on any other square without a checkmate being possible.
The late Sam Loyd first pointed out the peculiarity on which this puzzle
is based.
