If you’re new to swimming or if you’re just looking to broaden your skills beyond the dog paddle, here are some interesting things you should know about the four basic swimming strokes used in competition.

Front Crawl

Called the “freestyle” by competitive swimmers, the front crawl is the fastest stroke overall. Although a “freestyle” competition officially means that swimmers can use any stroke in the race, swimmers will almost always go with the front crawl for its speed and efficiency. Because lifting the head out completely of the water reduces speed, expert racers learn how to turn the head out of the water only high enough to take a breath.

Backstroke

Also known as the “back crawl,” this is the only competitive stroke done on the back—which makes for easier breathing, but it’s hard to see where you’re going. It’s also the only competitive style for which swimmers start in the water instead of diving in. Until the mid-20th century, backstroke swimmers held their arms straight in the underwater push, but Australian swimmers discovered using a slightly bent arm underwater improved speed. The bent-arm technique thus became the favored method worldwide.

Breaststroke

Generally considered the slowest of the competitive strokes, the breaststroke is difficult to learn and to master. Performing the breaststroke requires superb timing, and swimmers can be disqualified from a race if they miss even one stroke. A popular stroke with recreational swimmers because of its leisurely pace combined with its excellent aerobic benefits, the breaststroke is done by pulling the arms along the body while legs do a “frog kick.”

Butterfly

The newest stroke to competitive swimming, the butterfly was first swum as a separate Olympic event in the 1956 Summer Olympics in Melbourne. Called the “butterfly” because of its wing-like arm movements, the stroke is considered by many swimmers to be the most difficult stroke to perform well. The powerful pull-and-push movement with both arms makes the butterfly’s peak speed even faster than that of the front crawl, but the stroke’s recovery phase makes it slightly slower than the front crawl during a race.