In short: Placing a piece on the square in front of an enemy pawn, often a passed pawn, so that the pawn can't advance.
A pawn only moves straight ahead. If a piece stands on the square in front of it, it can go no further. Putting a piece there is called a blockade, and the square is called the blockading square. Most often you blockade a passed pawn, which could otherwise go all the way.
Who should blockade?
Any piece can blockade, but the knight is the most common. A minor piece gets a stable post on the blockading square, an outpost where no pawn can chase it away. A rook or a queen is too valuable for the job, and can be chased away by the opponent's minor pieces. The goal is then to win the blockaded pawn. The pawn's owner wants instead to drive the blockader away and get the pawn rolling again.
When the blockade breaks
At the AVRO tournament in 1938, Mikhail Botvinnik had a passed pawn on e6 against José Raúl Capablanca. Black's queen stood in front of it and held it back.
The bishop sacrifice 30. Ba3 lured the queen away from the blockade, and after that it went fast. See the whole game: Botvinnik–Capablanca 1938.
Nimzowitsch's word
It was Aron Nimzowitsch who in the 1920s made the blockade one of his key ideas, together with prophylaxis and overprotection. His ideas about stopping pawns with pieces live on, for example in the play against the isolated queen's pawn, where a knight on the square in front of the pawn is the classic answer.
Frequently asked questions
Why do you usually blockade with a knight?
A minor piece gets a stable post on the square in front of the pawn. A rook or a queen is too valuable for the job, and can be chased away by the opponent's minor pieces.
Who made the blockade famous?
Aron Nimzowitsch, who in the 1920s made the blockade one of his key ideas, together with prophylaxis and overprotection.
Updated November 14, 2026