Vancura position

The Vancura position is a specialized defense in rook and pawn versus rook. The extra pawn is a rook pawn, meaning it is on the a- or h-file, the two edge files. It has normally advanced no farther than its sixth rank, counted from its starting side, and the attacking rook stands in front of it, limiting the attacking king's lateral shelter.

Required defensive features

• The defending rook attacks the pawn from the side and keeps enough distance to check the attacking king.
• The defending king stays on the side opposite its rook so that it does not block the lateral attacks.
• The defending king remains near the far corner, where the attacking rook cannot force a reply with check and use that move to support promotion.
• If the pawn advances to the seventh rank, the defending rook moves behind it and continues to stop promotion.

The attacker tries to bring the king closer, block the checks, or free the rook from in front of the pawn. The defense alternates lateral checks with attacks on the pawn. Its essence is not one fixed square, but preserved checking distance and the option to switch behind the pawn.

Vancura does not make every rook-pawn ending a draw. A misplaced king, a rook that is too close, or a wasted move can destroy the setup. It differs from the Philidor position, which uses a third-rank barrier and is not limited to rook pawns.