In 1970 most skiers worldwide were still wearing leather boots; by the end of the decade their feet were encased in plastic. Although Bob Lange worked from 1957 to 1966 to invent the plastic boot, his impact on the sport was only truly realized in the 1970s. His design—a lower shell containing the foot and an upper clamshell overlap or cuff connected to it by a hinge or rivet—remains the basis of the boot the world skis in today. He made a boot sole the width of the ski and pioneered the adjustable buckle. As pro racing reached more televisions worldwide in the early 1970s, his Lange Cup series rose to international prominence.