The Knight Circuit

Knight vs. pawn: who wins? Well, if it’s just a king and knight on one side, they won’t be winning (outside of a spectacular circumstance!). The knight’s goal is to stop the pawn from promoting, or at least capture it the instant it does. That requires attacking a square in front of the pawn.

Black, to move, must obviously play 1. …Nd7 so that White does not promote. Then if 2. Kc6, Black plays 2. …Nb8+, occupying the square in front of the pawn. It is not simply about giving a check: 2. …Ne5+?? 3. Kc7 (D) wins for White, as the knight has no way back in front of the pawn!

Returning to 2. …Nb8+, White will try to chase the knight away with 3. Kc7, but Black will take a position on the other side of the pawn with 3. …Na6+, laughing like a mischievous child at a grumpy old man.

The knight can travel anywhere on the highlighted circuit of four squares and hold a draw. Even if it were currently on c5, 4. b8=Q Na6+ would fork and draw, which matters when the knight starts further away.

White to move, how do you draw? By attacking a square in front of the passed pawn. That would be 1. Nf4 c2 2. Ne2, reaching a ‘circuit square’ and stopping the pawn. 2. …Kd3 3. Nc1+ (D) is equivalent to the position above. The knight can never be chased away, and the game will be a draw, eg. 3. …Kd2 4. Nb3+ Kc3 5. Nc1 Kb2 6. Ne2 c1=Q 7. Nxc1.

In summary: a knight must attack a square in front of a passed pawn, and can often cycle through a ‘square’ of squares to hold its position. You can find fascinating examples where the side with the knight must be much more inventive, or explore the dynamics of knight vs. multiple pawns, as in Lei-Goryachkina, 2024.