British Chess Magazine, 1952
Mate in 8
Don’t be put off by the length of the problem, as it is probably easier to solve than the majority of three-movers. Black is basically reduced to shuffling his rook between a4 and a5, but White needs a plan.
Most black moves are met by immediate mates, and the only realistic key move, given the queen’s need to guard the bishop, is 1.Qg6, covering b1 should the pawn promote. 1...a5 allows mate in 2 by the switchback 2.Qc6, so Black must play 1...Ra5. Now the queen and bishop waltz down the board in tandem, until the queen can attack d2. 2.Bg5 Ra4 3.Qf5 Ra5 4.Bf4 Ra4 5.Qe4 Ra5 6.Be3 Ra4 7.Qd3, and mate next move cannot be prevented. Strictly speaking, the play consists of one long threat.
Jacob Hoover: One set mate is 1 ...Qxh6 2.Qxh6 mate. Because of this White must keep the h6-bishop guarded; if he doesn’t, Black escapes. This would mean unpinning the c2-pawn, but a random unpin of this pawn allows ...cxb1(Q/B) mate. The only move that guards both bishops is 1 Qg6!. The white queen and bishop then alternate moves as they inch ever closer to the black king.