Norbert Geissler
With its combination of beauty and simplicity this helpmate is the sort
of problem which sticks in the memory long after more complicated works
have been forgotten.
1.Rxa6 Qe6+ 2.Kc5 Sxa6 and 1.Rxb4 Qe7+ 2.Kc6 Sxb4.
Two harmonious solutions, with each rook capturing to free a flight square before being captured in turn.
Both mates are models. The white king is no idle bystander, but prevents cooks such as 1.Rb7 Qf2 2.Rd7 Qf6 and
1.Re4 Qa2 2.Re7 Qd5, while a black knight is used instead of a pawn to prevent cooks ending 2.Kc8 Qc7 or
2.Re6 Qc7.
Jacob Hoover: The knights swap roles between captured unit and mating unit, so we have the Zilahi theme.