Fosbury later recalled, "I knew I had to change my body position and that's what started first the revolution, and over the next two years, the evolution." At first, he tried to use a technique known as the upright scissors method. In this method, a jumper runs upright towards the bar, facing forward, and during his jump lifts his straight legs one at a time over the bar. High jump rules stipulate only that competitors must jump off one foot at takeoff; there is no rule governing how a competitor crosses the bar, so long as he or she goes over it.