The Dirty Dozen is an annual bicycle competition held in Pittsburgh, Pennsylvania. The event features thirteen of the steepest hills in the Pittsburgh city area, including Canton Avenue, which may be the steepest street in the world. The competition occurs annually on the Saturday following the Thanksgiving holiday each November. The event began with 5 riders, among them co-founder Danny Chew, in 1983 and grew to over 300 riders in 2011. The riders travel between hills at a neutral pace. A whistle signals the rolling start of each hill. The top male and female riders on each hill score 1 to 10 points, with the first place rider scoring 10 points and the tenth place receiving 1 point. The final standings are established by cumulative points throughout the event. In order to qualify as a fin