they may choose to hug the sprinter's line (a red line 85 cm up track) to force their opponent to come higher over the top of them. The sprinter's line defines the sprinter's lane; once the sprint is initiated riders may not drop into the sprinter's lane or cross out of the lane unless they have a clear lead over their opponent. Rules As defined by Union Cycliste Internationale (UCI) rules, the first round of competition used to qualify for the sprint competition is the flying 200 m time trial. In this round each rider completes two to three warm up laps and then completes the final 200 m, which is usually just under a lap. The number of riders that qualify for the sprint rounds depends on the competition; in World Cup competitions, 16 riders will advance and in a world championship, 24 riders will advance. The top riders are seeded in the following rounds, meaning the fastest qualifier will face the slowest qualifier and so on. Knock-out rounds then proceed, initially on a one race basis and then on a best-of three-race format from the quarter-final stage. Riders defeated in the earlier rounds may get a chance to continue in the competition through the repechage races. Great Britain and Germany currently hold two of the major titles in this event. Jason Kenny is Olympic men's sprint champion, and Kristina Vogel the Olympic women's sprint champion. Variants Keirin The Keirin is a variant of the sprint in which a higher number (usually 6–8, or 9 in Japan) of sprinters compete in a very different format. Riders are paced in the early laps by (and are required to stay behind) a Derny motorcycle, which slowly increases the speed of the race from 25 km/h to about 50 km/h. It then leaves the track with about 600–700 m remaining. The first rider across the finish line in the high-speed (sometimes 70 km/h) finish is the winner. Team sprint The men's team sprint (also known as the Olympic sprint) is a short distance three-man team pursuit held over three laps of a velodrome. Like the (much longer) team pursuit event, two teams race against each other, starting on opposite sides of the track, but at the end of the first lap, the leading rider in each team drops out of the race by riding up the banking leaving the second rider to