Why convoy fighters cannot be judged only by kills

Layered convoy defence began with fighters breaking attacking squadrons into smaller groups, followed by heavy anti-aircraft fire splitting those groups further before individual ships engaged the remaining aircraft. A fighter that chased an attacker away from the convoy could abandon its screening position and force shipboard gunners to distinguish friend from foe. The enemy still benefited from destroying scarce carrier fighters because every lost airframe reduced the patrols the carrier could generate, but kills were not the defender's primary measure of success. Missile-era engagements changed the calculation because a fighter could launch at range without the same prolonged pursuit, so Second World War kill ratios have to be read against the mission actually assigned.