Of all places, I ran across this explanation in the local business journal this morning. Some stock guy actually used it in his article to describe something...
He claims that the origin of the phrase "balls out" is this:
"Old steam engines had a governor rod with ball shaped spinning weights on the ends. When the engine was running at maximum speed centrifugal force moved the balls all the way out."
Of course I'm sure that many of us thought this phrase described something else completely...
True?