Last week we talked about luck statistics, which, you’ll recall, aren’t 100% luck. Batting average on balls in play (BABIP), home run to fly ball ratio (HR/FB), and strand rate (LOB%) are more like telltale signs: they’re influenced by so many little factors, including random chance, that they typically tend to even out over time. So when one of them is visibly out of whack, we can usually expect it to regress.
I’m not a statistician. I have a rudimentary notion of how to run a regression, but that doesn’t mean I could actually perform that bit of analysis in anything like a useful fashion. But that’s not really what we’re talking about here.
For most purposes, we’re not going to need to predict exactly how much better or worse a pitcher will be. It’s usually enough to say that we can expect his numbers to improve significantly/decline slightly/whatever as his luck statistics normalize. To this end, I’d like to call Ryan Vogelsong up to the front of the class.