Keirin became an Olympic cycling event at the 2000 Sydney Games.
Keirin originated in Japan in 1948 as a betting sport on specially built tracks. Riders initially follow a motorized pacer, traditionally called a derny, which controls the speed before leaving the track several laps from the finish. The cyclists then sprint for the line without the pacer.
The Olympic version developed from Japanese keirin but uses international track-cycling rules. It became part of the Olympic programme in Sydney in 2000 for men, and the women’s keirin was added at the 2012 London Games.
Keirin races require both sprint power and careful positioning. Riders must judge when to move around the slowing pacer, avoid contact, and time their final acceleration. It is different from the individual sprint, where riders race directly against opponents from the start.