Doubled rook pawn — the corner holds two as well

Draw White to move · Pawn endgames · Difficulty about Elo 1100

The plan

Two whole pawns up — and still only a draw. Against the rook pawn, material doesn't count, a single square does: the corner. The white king can never drive the black one out of it without stalemating him, and the second pawn changes nothing about that — it only supplies waiting moves, and waiting moves help against zugzwang, not against geometry. Measured: in the starting position ALL five white moves hold the draw; White can do nothing wrong here, and just as little can he win anything. How much everything depends on the file and not on the pawn count is shown by the counter-test: put either of the two pawns on any of the seven other files, and White wins in all nine measured cases. And there is a subtlety to go with it: a single b-pawn on the fourth rank also holds only a draw here, the same pawn one rank further back — where it keeps a reserve tempo — wins. So a tempo very much does decide games, just not on the edge, where the corner swallows every tempo. Black can make exactly one mistake in this endgame, namely leaving the corner; at the decisive moment only one of two moves still holds.

Rule of thumb: with the rook pawn you don't count pawns, you count squares.

Why this level: Even two rook pawns don't win any more

The solution, move by move

1. 1. a5 White pushes whatever there is to push. It is completely irrelevant: all five moves in the starting position lead, measured, to the same draw.
2. 1… Kb8 Black shuttles stubbornly between a8 and b8 — nothing more is needed.
3. 2. Kb6 The king comes in as close as it possibly can. On any other file this would be the winning position; on the edge it lacks the outflanking square on the far side of the pawn.
4. 2… Ka8 Back into the corner. Here the step to c8 still holds too — both moves are a measured draw. It only gets tight for Black once the pawn has reached the seventh rank.
5. 3. a6
6. 3… Kb8 Forced and yet safe: Black has only this one move here at all, and it is enough.
7. 4. a7+ White tries everything: the pawn advances with check —
8. 4… Ka8 The ONLY holding move of two. A step to c8 instead of into the corner, and the game would be lost (sideline). That is the whole mistake Black can make in this endgame.
   Sideline 4… Kc8 The only mistake Black can make in this endgame at all: leaving the corner. 5. Kc6 At once the white king cuts off his way back. Without the corner, the rook pawn is suddenly as strong as any other pawn. 5… Kd8 6. Kb7 Ke7 7. a8=Q The queen stands. It was not the material that decided, but that one square a8.
9. 5. a4 — and the last 'waiting tempo' delivers STALEMATE. Even the second rook pawn could not break the curse of the corner: a draw.
   Sideline 5. Kc6 Instead of the stalemating move, the attempt to avoid stalemate: the king steps aside and gives the opponent room. 5… Kxa7 Then the pawn simply falls — and with the second rook pawn the same game begins all over again. Even so it stays a draw: the rook pawn doesn't win, whether there is one of it or two. 6. Kb5 Kb7

More in Pawn endgames

• Shouldering — leading with the shoulder White wins
• The doubled pawn as a tempo reserve White wins
• The queen skewer — curse of the long diagonal White wins
• Connected passed pawns — advancing under cover White wins
• The race — promoting with check White wins
• The stalemate trap — pawn on the sixth White wins