CHESS SOLUTION:

Black is lost, eg

A: 1...Bb3; 2 e8 = Q , b1 = Q; 3 Qe4 + , Kc1; 4 Qxb1 + , Kxb1; 5 Rxb3 + B: Spassky tried 1...b1 = Q , but had to resign after 2 Rxb1, Kxb1; 3 Kd4, Kc2; 4 Kc5 White wins the bishop for his e - pawn, captures Black's f pawn, and then queens his own