A three-mover illustrating a sharp idea. It was an achievement to
improve the construction of a problem by as fine a composer as Friedrich
Chlubna.
An excellent key 1.Be4 threatens short mates 2.S any, but allows two captures with check. The knight
responds each time with a carefully chosen cross-check. 1...Qxe4+ 2.Sd5+ Kxd5 3.Rd6 and 1...Bxe4+
2.Sc6+ Kd5 3.Se7. Not 1.Bg8? Bf7!