Shaquille O'Neal announced his retirement today after 19 years in the NBA. I've loved Shaq ever since I was a massive 5'9" sixth grader who the Lilliputian other kids called Baby Shaq.
But one thing I could never understand is why his free throw shooting never really improved. Take a look at this graph plotting his free throw shooting against his age. He was all over the map during his career.
I created this graph using Matt Stiles' visualizer, which lets you play with O'Neal career stats to your heart's content.