An early 20th Century pitcher.
While using a feed chopper on his farm, Brown slipped, inadvertently shoving his hand into the blades. His index finger was pretty much chopped clean off, and the rest weren’t much better. Fortunately, a competent doctor managed to repair and save every finger but the index. Unfortunately, during the healing process, Brown accidentally fell and broke the bones in his hand some more. Even worse, he didn’t tell anyone about it, either because he was embarrassed by his clumsiness, or because the pain hardly seemed notable when compared with the feed chopper incident. Regardless, the bones didn’t set correctly.
As a boy, Brown had spent the part of his childhood that didn’t involve horrific mind blanking pain throwing stones at holes in his barn. Over time, he got pretty good at it. With his hand beyond destroyed, he took up the hobby again, this time probably out of anger at the entire institution of farming, and found that he was no longer good at it. He was amazing.
By an insane stroke of luck or possibly—because he was a Jedi and this had been the plan all along—when he threw a baseball with his mangled hand it came off with a bizarre spin, which, if you’re not a baseball fan, is kind of useful. His curve ball, for example, was rated “most devastating” by Ty Cobb, a man who still holds the record for highest career batting average and who just might be the greatest baseball player to have ever lived.