As a kid, I spent one summer trying to get the hang of this near-impossible, absurd, pointless, and extremely fatiguing stroke. Never could.
In the summertime, it is fun, though, to see the kids' swim teams do their best with it and, at high levels, it's more interesting to watch than any other stroke.
I found myself wondering who was to blame for this monstrosity, which seems to have been invented around 1933.
Here's the history of the "Fly."