The protected passed pawn — the fetter

White wins White to move · Pawn endgames · Difficulty about Elo 1500

The plan

White's passed pawn is defended by a pawn of its own, and that changes everything. The black king stands right next to it and still may not touch it — he is a guard with no hope of ever taking the prize. That ties him down for the rest of the game: if he leaves the passed pawn, it queens. The white king, meanwhile, has no task left at all and goes for a walk, right across the whole board, to catch the single black pawn; every move counts here, because the pawn is running too. If the black king later changes his mind and goes for the DEFENDING pawn instead, it is too late — then the passed pawn runs through by itself. That is the difference from the distant passed pawn: that one is sacrificed and only buys time, this one is never sacrificed and works for free. Only one thing must never be done: dissolving the protection by pushing the rear pawn up.

Rule of thumb: a protected passed pawn costs the opponent a king — leave it standing where it stands, and go eat elsewhere with your own king.

Why this level: A protected passed pawn ties down a king for good

The solution, move by move

1. 1. Ke4 The ONLY winning move. The black pawn needs three moves to promotion, the white king is just barely four squares from the corner — only this one square gets him into the square. Of the eight other moves, one is still a draw (advancing the passed pawn), the remaining seven LOSE. Notice what the king does here: it walks AWAY from its own pawns. It is allowed to, because the two of them look after each other.
   Sideline 1. b6 The reflex to just let the passed pawn run. That gives up exactly what makes White strong: one rank further on it is no longer defended. 1… Kxb6 And it is captured at once. A lone pawn on the rook-file side against the king in front of it is a draw — the win has become half a point. 2. Kd6 Kb7 3. Kd7 Kb8
2. 1… h3
3. 2. Kf3 Again the only move — from here it is pure counting of the square. One detour, and the pawn is through.
4. 2… h2
5. 3. Kg2 And again. The king places itself in front of the queening square; that settles the pawn, because promoting would only cost him the fresh queen.
6. 3… Kb6 Black gives up the watch and tries to get at the pawns. The protected passed pawn itself is untouchable, so the king aims at the DEFENDING pawn.
7. 4. Kxh2 Now the pawn can be gathered in. The excursion has cost the white king six moves — and not one of them was missed by his own pawn structure, because it defends itself.
   Sideline 4. c5+ The mistake this lesson is meant to show above all: White pushes the defending pawn up and so gives up the protection. The move even offers check and so looks active. 4… Kxc5 The king that had to watch the whole game strikes. Now both pawns are just pawns. 5. Kxh2 Kxb5 The second one falls too. Bare kings, a draw — a single pawn move has cost the whole point.
8. 4… Kc5
9. 5. Kg3
10. 5… Kxc4 The defending pawn falls, but the price is the last connection to the passed pawn.
    Sideline 5… Kb6 Instead of capturing, Black stays on guard. That holds up the passed pawn — but costs the last chance, because now the white king simply comes back. 6. Kg4 Kc5 The black king shuttles between two tasks: guarding the passed pawn and attacking the defending pawn. Both at once is impossible — the passed pawn is defended and cannot be captured. 7. Kf5 Kb6 8. Ke6 Kc7 9. Kd5 The white king is back, now it is three against one. So both black attempts lose: the greedy one and the patient one.
11. 6. b6 The ONLY winning move, and from here on only the square counts again: three moves to promotion, the black king needs four. Any waiting move would throw everything away.
12. 6… Kd5
13. 7. b7 This too is the only move. The pawn that has just stood there the whole game holding the enemy king in place runs through by itself in the end.
14. 7… Kc6
15. 8. b8=Q

More in Pawn endgames

• The distant passed pawn — the decoy White wins
• The pawn breakthrough — a sacrifice tears the path open White wins
• The active king outweighs a pawn Draw
• Wing majority 3 against 2 — the candidate first White wins
• Corresponding squares (Lasker-Reichhelm 1901) White wins
• One pawn holds two — the saving trade Draw