Passed pawn

In chess, a passed pawn is a pawn with no opposing pawns to prevent it from advancing to the eighth rank; i.e. there are no opposing pawns in front of it on the same file nor on an adjacent file. A passed pawn is sometimes colloquially called a passer. Passed pawns can be an advantage because only the opponent's pieces can prevent them from promoting.

In the diagram at right, the white pawns on b5, c4, and e5 are passed pawns. Black's pawn on d4 is a passed pawn. If Black plays fxg4, then Black will also have a passed pawn on g4, and White will have a passed pawn on f4.

A passed pawn that is protected by its own pawns is called a protected passed pawn. In the first diagram in this article, the pawns on the b and e files are protected passed pawns. Two or more passed pawns on adjacent files are called connected passed pawns (see connected pawns), and they are very strong. In the diagram at the top, White's b and c pawns are connected passed pawns. A pair of connected passed pawns is sometimes called a steamroller. It is often strategically advantageous for the side with connected passed pawns to place them on the same rank and then advance them in tandem, because this makes them more difficult to blockade.

Sometimes, minor pieces are sacrificed so that a pawn can have a clear path to promotion on the eighth rank. In the example at the right (Botvinnik versus Capablanca, AVRO 1938), in order to capitalize on the passed pawn on e6 and break its blockade by Black's queen, White continued 30. Ba3! Qxa3 31. Nh5+! gxh5 32. Qg5+ Kf8 33. Qxf6+ guaranteeing the e-pawn's promotion. The passed pawn's value is well worth the sacrifice of both the knight and bishop because it clears the path of the black queen and knight. The only pieces preventing the e-pawn's promotion are the black queen and knight, and once they are gone, the e-pawn has a free path to promotion because Black's pawns are helpless to stop it. Had there been a black pawn on the seventh rank that challenges the advancement of the e-pawn, it could have stopped the progress of the white pawn.

An outside passed pawn is a passed pawn that is on or near the left or right edge of the board, and is separated by a number of files from the rest of the pawns. Such a pawn often constitutes a strong advantage for its owner because the opposing king does not have the range to cover both sides of the board.

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