Josh Weinstock over at The Hardball Times took a look at pitcher’s repertoires and found that pitchers who throw a lot of changeups tend to give up fewer hits on balls in play. It’s not an enormous difference, something like four or five hits over a full season for starting pitcher. But it looks like there is a real difference, and helps explain why changeup-happy Johan Santana consistently gives up 15-20 fewer hits than expected every season.