Because they could not effectively dogfight the Zeroes, Henderson Field's defenders could not gain air superiority and completely drive off Japanese attacks. They realized that the best thing they could do was disrupt up each day's raid, whittle down the Japanese, and then break off to fight another day. With this in mind, their primary targets became the bombers rather than the fighters, and many of the tactics introduced were largely devised by Marine Major John L. Smith. The American pilots always sought to begin their attack at least above the Japanese formations, and they concentrated their attacks on trailing aircraft. This gave them good angles to shoot at the exposed fuel tanks of the Japanese bombers, and it also presented a difficult gunnery problem for the bombers, since the high overhead passes of the American fighters put them into the blindspots of the Japanese gunners. This tactic also caused the escorting Japanese fighters to climb and burn more of their fuel, thus reducing the already limited time they could spend over Guadalcanal itself.