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.
[Illustration]