In this series of articles, we are examining chess endgame strategy for King and Pawn endgames, with an emphasis on those positions where the Pawns can defend themselves against the King.
The first position we examined was that where two Pawns stand on adjacent files, and one Pawn defends the other. We saw that the King can't capture either Pawn, thus making the Pawns invulnerable.
Two Passed Pawns with an Empty File Between Them
The second position we'll examine is where White has two passed Pawns, standing on the same rank (the ranks are the horizontal rows) and have an empty square between them. The position exists when White has a Pawn on b4 and d4, provided Black doesn't have any Pawns on the a- through e-files.
The procedure works like this: as soon as Black attacks one of the Pawns with his King, the other Pawn (the one not being attacked) advances one square. Now if the King captures, he'll be too far behind to catch the advanced Pawn to prevent it reaching the promotion square.
For example, in the position we mentioned earlier, if Black moves his King to d5 (attacking White's piece on d4), White immediately moves his other Pawn to b5. If the King ever captures on d4, he won't be able to prevent the button on b4 from advancing all the way to b8, where it will become a Queen.
A Practical Example
Get a chess board and set up a position as follows: White K on b1, Pawns on b4 and d4; Black K on b6, P on h7.
White has to prevent Black's guy on h7 from promoting, so his first move must be: 1.Kc2 (or Kc1). Now Black moves 1... Kb5 (attacking White's piece on b4). 2. d5! (indirectly protecting the piece on b4).
Now Black can't capture the Pawn on b4, else the Pawn on d5 goes on to promotion. And Black can't easily maneuver, because several squares in the immediate vicinity are being attacked. So the best King move for Black would be 2... Kb6, going right back where he came from. Now White can go over and capture the Pawn on the h-file at his leisure, and then come back to help one of his own Pawns reach the promotion square.
The big advantage of this position is that the self-defending Pawns act like a ball and chain around the ankles of the Black King. He can't leave the immediate vicinity in order to help his own position. The King is stuck watching the invulnerable White Pawns. It's a very useful tool to have in your endgame strategy arsenal.
