Solution to Chess Problem Number 6
The theme of this problem, my first composed and published problem at the age of 15, is a simple example of an incomplete block problem. Here white must find a move which puts black into zugswang so that every subsequent move by black leads to mate. This is in contrast to a complete block problem in which white must keep black in zugswang.
The key move is 1. Rxf5 no threat.
1...Rxf5 2. Qe4 mate.
1...Bxf5 2. Nf3 mate.
1...R on king file 2. Bc5 mate.
1..Ng6 any 2. Bxe5 mate.
1...Nb6 any 2. Rc4 mate.
1...Rd5 2. Qe4 mate.
1...Bxe2 2. Nxe2 mate.
1...B else 2. Nf3 mate.
1...d1=Q 2. Qxd1 mate.
Of course in terms of construction it is easy to see this problem has a weakness. The R on f8 is well away from any sort of action so points the way to this being the piece which would make the key move. Bringing the rook into play leads to Rxf5 overloads blacks defences by eliminating a guard of e4.