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.

» Continue reading “Alphabet Soup: Making An Example Of Ryan Vogelsong”

Last week on Alphabet Soup, we talked about peripherals that can help characterize a pitcher’s style: ground ball, fly ball, high strikeouts or contact. This week, we’ll look at factors outside a pitcher’s direct influence that can skew his results.

Once the ball leaves a pitcher’s hand, he has very little control over where it ends up. “Luck” stats – a combination of pure chance and factors that tend to even out over time – can be excellent indicators of whether a pitcher’s ERA is artificially inflated or depressed.

BABIP you should recognize from the posts on offensive statistics. Along with LOB% and HR/FB, it can serve as an indicator that a pitcher’s numbers are probably due to regress toward the mean.

BABIP. Batting average on balls in play should sound familiar. It means exactly the same thing as it does for hitters: the ratio of balls put in play that actually fall in for hits. Batters necessarily have more control over this than pitchers do, since they’re the ones putting the balls in play.

» Continue reading “Alphabet Soup: Luck, Be A Lady”