The Grumman F-4 Wildcat was an carrier based fighter first used by the Royal Navy (called the Martlet) and the United States Navy in 1940.
The Wildcat was the only effective fighter in the Pacific Theater used by USN and USMC (United Marine Corp) in 1941 and 1942. It replaced the Brewster Buffalo which was considered obsolete.
Although the F-4F was outperformed by the Mitsubishi A6M Zero, in speed (318 F-4F vs 331 kts – Zero) and maneuverability , the Wildcat pilots developed superior tactics such as the “Thatch Weave”.
The F-4F had a kill ratio of 5.9 to 1 in the early stage of the war (1941-42) and an overall kill ratio of 6.9 to 1 for the remainder of the war.