Before the war our own fighter squadrons, together with those of other countries, flew in compact formations built up from tight elements of three airplanes. Such formations were ideal for spectacular flypasts, and although every fighter pilot must be able to 'formate' closely on his leader to climb through a cloud, this close style was to be of little value in great air battles.
In Spain the German fighter pilots soon realized that the speed of thier 109s made close formation impractical for combat. The large turning circles of the curving fighters dictated that a loose pattern was the only method in which individual pilots could hold thier position in the turn and keep a sharp lookout at the same time. The high speeds, especially from the head-on position, made it essential to pick out and identify enemy aircraft as soon as possible, so that the leader could work his way into a good attacking position. The simple requrement was for a loose, open-type of combat formation with the various airplanes flying at seperate heights which would permit individual pilots to cover each other and search a greater area of sky than before.
Credit must be given to the Germans for devising the perfect fighter formation. It was based on what they called the Rotte, that is, the element of two fighters. Some two hundred yards seperated a pair of fighters and the main responsibility of the number two, or wingman, was to guard his leader from a quarter or an astern attack. Meanwhile the leader navigated his small force and covered his wingman. The Schwarme, four fighters, simply consisted of two pairs, and when we eventually copied the Luftwaffe and adopted this pattern we called it the 'finger-four' because the relative positions of the fighters are similiar to a plan view of one's fingertips.