How did doubling an enemy line concentrate naval firepower?

In the context of naval warfare during the age of fighting sail, "doubling" was a tactical maneuver used to concentrate firepower against an enemy fleet.1

By positioning ships on both sides of an enemy's line of battle, a commander could effectively surround individual enemy vessels. This allowed the attacking fleet to bring a significantly superior amount of force to bear on specific targets, overwhelming them with broadside fire from multiple directions simultaneously.1

This tactic was one of several maneuvers, including "breaking the line" and "raking," designed to disrupt the enemy's tactical cohesion and overcome the limitations of the rigid, single-column formations that dominated the era. By placing the enemy between two lines of friendly ships, the attacker could maximize the destructive potential of their guns, forcing the trapped ships to defend themselves from both sides at once.1