Complex sentence: Many rook and pawn versus rook endgames reach either the Philidor Position or the Lucena Position if played accurately (the defending side tries to reach the Philidor Position; the other side tries to reach the winning Lucena Position).
Split into simpler sentences: Many rook and pawn versus rook endgames reach either the Philidor Position or the Lucena Position. If played accurately (the defending side tries to reach the Philidor Position; the other side tries to reach the winning Lucena Position).