Problem #11 is taken from a position in the game Nanarokov - Grigoriev played in Moscow in 1923. Good luck working through the solution which will be posted subsequently.

Black to move and win (Nanarokov - Grigoriev, Moscow 1923)

The Solution:

The stunning move 1 ... Bd6! caused Black to resign immediately. He obviously did not want to choose among the following moves:

2 Bxd6 interferes with the rook and allows 2 .. d1=Q, winning easily;

2 Rxd6 interferes with the bishop and allows 2 ... h2, queening a pawn as well (3 Rh6 d1=Q);

2 Kxd2 Bxc7 3 Rh8 h2 forces White to give up the rook for the pawn, leaving Black with the two bishops against a lone king, a fundamental mate.