Greg Maddux faced 20,421 batters in his career. Just 310 of them saw a 3-0 count. That's roughly one every three starts. Thanks to MLB Trade Rumors for the research.
So in other words, 1.5% of the batters Maddux faced over his career saw him go to a 3-0 count (meaning that he had very little control). Such performance does not happen by accident and is a testimony to the tremendous work ethic he brought to the game daily. How much better off would be as a nation if each one of us put that kind of dedication into our jobs? One can only wonder.