A neat miniature by probably the most famous collaborators in chess problem
history, who composed together for over fifty years.
Solution: 1.Bd5 threat 2.Bc6 mate. 1...Sf6 only delays the mate by a
move, but after 1...Sxf8 the surprising continuation is 2.Bf3!
placing Black in zugzwang and giving the variations 2...Sd7 3.Bh5,
2...S else 3.Bc6 and 2...Kd7 3.exf8Q.