Before the Air Force 1, hightop basketball shoes featured a straight cut across the top. Made sense, a hightop was a hightop, and that was that. Worked for the Converse All Star. But Kilgore, inspired by the Approach hiker, slanted the cut from front to back, so it angled lower towards the Achilles. This made for a shoe that provided the same support, only with more flexibility. Genius.