Most of the time, Joe Kelly doesn't have to peek at the radar gun. No, the burn of a baseball's stitches against the tips of his fingers -- "That tug out of your hand when everything is going right," Kelly says -- usually tells him whatever he needs to know about how hard he's throwing.
When it doesn't? When the ball doesn't speak to the Boston Red Sox reliever?
"Oh, you can hear the crowd," Kelly says, prompting eavesdropping closer Craig Kimbrel to utter an "ooooooh!" from a neighboring locker. "That kind of lets you know too.