Mate in 2

White is poised to deliver battery mates if either black rook moves: 1...Rab2 (or any move of the a2-rook) allows 2.Rxa3#, while 1...Rbb2 (or any move of the b1-rook) is met by 2.R(x)c1#. So it seems all White needs to do is wait and create a block.

Let's analyse the options. 1.b8(=any)? is of course refuted by 1...Rxb8+!. A bishop move — say, 1.Bh8? — permits 1...d4!. 1.Kc8? looks promising, until you spot 1...Rc2!, pinning the wR and nullifying 2.Rxa3#. Any other king move invites checks that White cannot respond to with mate. So, by elimination, the key must be a knight move.

However, any move of the d3-knight unguards b2, conceding a flight to the bK. Therefore, we’re after something that provides a mate after 1...Kb2. That narrows the candidates to just two: 1.Nc1 and 1.Nc5 — the only choices that cover b3, enabling 1...Kb2 2.Rc4#, for example. But clearly, the latter must be the key: 1.Nc1? destroys the set mate on c1 and fails, say, to 1...Rbb2.

Now for the full play:

1.Nc5! zugzwang

1...Rab2, Ra~ 2.Rxa3#

1...Rbb2, Rb~ 2.R(x)c1#

1...Kb2 2.Rc4#

Simple — but with a tinge of wicked!