Butterfly is the most exciting stroke for swim watchers. It appears to be difficult, an exhausting combination of coordination and strength. A little history might help to modify such thinking.

Butterfly was developed by breast-strokers for two purposes. It decreased resistance with an over-water recovery, and it increased propulsion with a longer application of arm-stroke force.

Breaststroke competition was allowed with either underwater or over-water recovery as long as a breaststroke kick was used. Then, in 1935, an Iowa swimmer initiated the up-and-down, two-legged “dolphin” kick that we see today.

But it was almost another 20 years before Butterfly was accepted as a separate Olympic stroke, and then a few years more until it became a separate event for high school competition.

It seems laughable today that it was deemed too strenuous for so long. Competitors much younger than high school age are now practicing long series of butterfly repeats.

The easiest way to understand that Butterfly can actually be comfortable, and even relaxing, is to forget its derivation from Breaststroke. The stroke is instead better considered as a double-arm crawl.

It is best learned by ignoring the lower body and focusing on just upper-body movements, as the whole body is brought past the hands.

Starting from a push-off with arms extended at shoulder width, the swimmer catches and holds water, pressing out (see illustration) with elbows high to bring the shoulders to the hands.

Then, with elbows still high, the grip gradually narrows as the hips are brought to the hands.

After full arm extension, the hands are swept out and over the water into the same extended glide from which the stroke began.

The key to being able to repeat this motion is to hold the glide until the hips rise up behind the swimmer before performing a second stroke. Learning is best accomplished by just a single stroke, repeating the motions above.

Eventually the swimmer will feel relaxed and comfortable enough to add a second stroke, and thus establish the Butterfly rhythm.

What about dolphin kicking? Practice it separately, loose from hips to ankles. Eventually it will naturally fit into the stroking rhythm and assist the hips in staying at the surface while providing additional propulsive force.

Try just this much. You’ll find Butterfly easier and more relaxing, and even fun.

Dr. Bob Colyer of Bluffton is an actively retired college professor, coach and author of “Swim Better: A Guide to Greater Efficiency for Swimmers & Instructors,” directed primarily to non-competitors. bobcolyer @yahoo.com