Backward pawn
A backward pawn is a pawn that has fallen behind the pawns on neighboring files and cannot safely advance, because the square in front of it is controlled by an enemy pawn.
A pawn becomes backward when its neighbors have moved past it and no friendly pawn can ever come back to defend it. Pawns only go forward, so the gap is permanent. Worse, the square directly in front of the pawn is guarded by an enemy pawn, which means stepping forward simply loses the pawn.
The damage is twofold. The pawn itself is a target, because only pieces can defend it, and those pieces get tied to a dull job; on a half-open file, enemy rooks can press on it from the front. The square in front of it is also a hole, where an enemy knight or bishop can settle with no pawn able to chase it away.
If you own one, try to free it with a timely advance supported by other pawns or pieces, or exchange the enemy pawn that guards the stop square. If you face one, plant a piece on the hole, double rooks on the file, and keep the pressure on until the defender runs out of moves.
A common mistake is to call any slow pawn backward. The test is strict: the neighbors must be further ahead, and the stop square must be under enemy pawn control.
Also worth reading is Najdorf structure. The Sicilian Najdorf pawn setup after ...a6 and ...e5, with Black pawns on a6, d6 and e5 against White's e4, which gives Black a firm grip on d4 but leaves a hole on d5 and a backward d6 pawn.
It sits close to Minority attack. A minority attack is a plan in which two or three pawns advance against a bigger enemy pawn group on the same wing, aiming to leave a lasting weakness behind rather than to make a passed pawn.
It sits close to Protected passed pawn. A protected passed pawn is a pawn that no enemy pawn can block or capture on its way to promotion and that has a friendly pawn diagonally behind it, ready to recapture if it is taken.
Where "Backward pawn" fits your own play is easier to judge with a coach reading your games; the first lesson is a paid one-on-one review that ends in a written plan.
Related terms
A weak pawn is a pawn that is hard to defend with other pawns and so must be protected by pieces, making it a long-term target for the opponent.
An isolated pawn is a pawn with no friendly pawn on either neighboring file, so no other pawn can ever defend it and the square in front of it is a lasting weakness.
A weak square, also called a hole, is a square that a player's own pawns can no longer guard, so an enemy piece can settle there without being challenged by a pawn.
An outpost is an advanced square, usually in the opponent's half of the board, that is protected by one of your own pawns and cannot be attacked by an enemy pawn.
A half-open file is a file on which one side has no pawn while the opponent still does, giving the side without a pawn a line along which to attack the enemy pawn.
A blockade is the plan of stopping an enemy pawn by occupying the square it must move to next, most often a passed or isolated pawn, with a piece that stays safe and useful there.
Guides that go further
What to decide first, the questions to ask, what a first lesson should show and the red flags to avoid.
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