Blockade

The blockade is a positional technique for neutralising a dangerous pawn. A piece — usually a minor piece, ideally a knight — is placed directly in front of the pawn. The pawn cannot advance because the blocker is in the way; the blocker is supported by other pieces; the pawn becomes a permanent target rather than a permanent threat.

The blockade is most often used against passed pawns. A passed pawn is dangerous because it can promote. A blockaded passed pawn cannot move at all, and if the blocker is well-supported, the pawn is effectively neutralised. Nimzowitsch’s My System devotes an extended chapter to the blockade, arguing that the blockader’s job is not just to stop the pawn but to make its existence costly.

The blockade also applies to pawn chains and centres. A knight on d6 sitting in front of a White pawn on d5 blockades the entire chain — it cannot advance, the pieces behind it are restricted, and the position takes on a fixed character that favours the blockader. This is one of the central ideas in the French Defense’s pawn structure.

Knights are the best blockaders because they attack in directions a pawn cannot, making them harder to dislodge. Bishops can blockade but are vulnerable to enemy pawn moves on the same colour. The king sometimes blockades in the endgame; the queen rarely should, since blockading is too modest a job for the most powerful piece.