Around the world, top athletes dream of proving themselves at the Olympics. But in order to keep the Games at a manageable size, not every sport can be included. The International Olympic Committee (IOC) has strict criteria for evaluating potential events, ranging from the history and tradition of the sport to its drug testing procedures. The five sports below all have a wide international following, and a few have even made a fleeting appearance in Olympic history. But none have become an Olympic event—at least not yet.