I get this on occasion and when I stop to analyze what I did wrong, this is what I usually find. I'm almost always fishing in streams with a good amount of current and, since I usually strip off the line that I think I'll need before I start casting, sometimes it ends up floating downstream; to the left, on me (another Line Control issue).
When this happens and with a lot of line in the air on the false casts to get set up for the cast that I want to make (I'm a righty and I'm almost always casting upstream; to the right, away from the direction of the floating line), I sometimes get the line wrapped around the butt of the rod. Frustrating, since it turns what you'd planned to be a nice cast into a shorter cast "puddle" of line.
As a "kicker", I sometimes get a nice strike while I'm trying to get the line mess off the back of the rod. I don't think I've ever been successful hooking and landing a fish when that happens, but I must put on a pretty comical show when I try.............