Entertaining chess puzzles sweeten life. Today's puzzle: White to move, checkmate in two. The position dates back to Erich Brunner in 1926 – and it's interesting precisely because it doesn't look like a typical two-mover at all. You try direct checks, examine rook moves, look for queen captures, and after a few minutes realize: the obvious ideas aren't the answer.
The solution is:
1. Te1!The rook moves to e1, positioning itself preventively on the back rank, protecting the king against Qh1, and thus unleashing the knight. And with that, Black's position is frozen in a very unpleasant way. The rook was superfluous on the fourth rank anyway (the rook on a4 alone covers b4 and c4). Black is in zugzwang: he has to move, but every move will damage something. A few variations from Black's perspective.:
1. ... Dd4 2. Dxe8#
1. ... c4 2. Dxc4#
1. ... Kxa4 2. Da6#
1. ... Lc6 2. Da6#
1. ... L~ 2. Dd7#
1. ... Dh1 2. Sxc3#If the black queen moves differently, the protection of e8 or c3 is lost, depending on the square. The interesting thing is that many obvious moves fail by a narrow margin. For example, a rook move to d4 looks very tempting, but then the black queen has resources on the diagonal. Direct checks seem intuitive at first, but more likely lead to checkmate in three. A silent move that forces nothing – except that every subsequent move by Black loses.