Competitors in freestyle swimming can use any of the unregulated strokes such as front crawl, dog paddle, or sidestroke. Standalone freestyle events can also be swum using one of the officially regulated strokes (breaststroke, butterfly, and backstroke). For the freestyle part of medley competitions, however, one cannot use breaststroke, butterfly, or backstroke. Most competitive swimmers choose the front crawl during freestyle competitions, as this style provides the greatest speed. Freestyle competitions have also been swum completely and partially in other styles, especially at lower ranking competitions as some swimmers find their backstroke quicker than their front crawl. During the Olympic Games, front crawl is swum almost exclusively during freestyle.