Named after the 18th-century master François-André Danican Philidor, this position demonstrates how to hold a draw when defending a rook endgame with a pawn down. The key defensive idea has two phases: first, keep the rook on the third rank (the sixth rank from the attacker's perspective) to prevent the enemy king from advancing, creating a barrier.
Once the attacking side pushes the pawn to the sixth rank (they must eventually commit), the defending rook switches to the first rank (behind the pawn) and delivers checks from a distance. Because the attacking king cannot hide from the checks (it must stay near the pawn), the defender achieves a perpetual check draw.
The critical requirement is that the defending king must be on the back rank in front of the pawn. If the defending king is cut off to the side, the position may be lost. Understanding the Philidor position and when it can be reached is essential for practical rook endgame play, as these endings are the most common type of endgame in tournament chess.