Today I bring to you a fun little puzzle. Now if you’ve ever tried to checkmate with two knights against a lone king you know it can’t be forced. Unless the enemy king is feeling a little reckless and drives itself into the corner it is safely a draw despite your being six points of material up. The option to stalemate provides an easy defense for the inferior side.
In the situation below white has a win. Be wary when solving that’s it not as easy as it looks. If the black king is allowed to escape to b7 it’ll be difficult to round back up. Proper play is to stalemate the enemy king on the edge of the board while blockading his pawn. Don’t capture it whatever you do. The tempi that it uses as it rushes headlong to the queening square can be used to maneuver your knights into position. There is no stalemate as long as the pawn has moves left. In this particular puzzle I’ve graciously provided you absolutely no extra moves to work with. Good luck! See one possible solution below.
1. Nc5 a5 2. Kd5 a4 3. Kd6 a3 4. Kc7 a2 5. Nd7 a1=Q 6. Nb6# 1-0
The situation is a win because the pawn is behind the Troitsky Line. The ‘line’ is a set of discrete points a4, b6, c5, d4, e4, f5, g6, and h4 (reverse it if you’re black). These endgames are very rare but beautiful; they take a remarkable amount of precision and are one of the most difficult to win. In many cases they cannot be won under tournament conditions since the game is drawn after 50 moves and they can take more than double this amount. Remember the technique of stalemating the king, where having to move leads to deterioration of the position. This theme, known as zugzwang, will come up again and again in endgames.