I love pop flies. That’s not a normal thing, even for a huge baseball fan to say. I know that. But I love watching good pitching, and inducing popups is good pitching.
Popups are nearly as good as strikeouts. They strand runners, and even the worst infield can turn them into outs. They have an average BABIP of .020.
So who is really good at inducing popups? Here are the leaders in pop-up rate over the past five years (2005-2010) for those pitchers who have faced more than 1,000 batters.
Bartolo Colon: 13.80%
That’s a lot of good relievers, DIPS defying Young, and … huh … Colon. But do these guys actually induce a lot of popups? Or do they just induce a lot of fly balls? Presumably a pitcher who generates a lot of fly balls can generate a lot of pop flies as a natural consequence of keeping the ball in the air all the time. Young, in particular, has the highest fly ball rate for that same group of pitchers. He is probably not so good at inducing popups as he is at inducing fly balls, a totally normal percentage of which stay over the infield.
I’m more impressed when a pitcher can manage to turn an abnormal amount of his fly balls into popups. Who are the leaders for the last half of the decade in popups per fly ball (IFFB/FB)?
Meredith might be on this list due to luck. He generates so few fly balls (less than 20 percent of all balls in play) that it wouldn’t take many extra popups to thrust him into the league leaders. Rivera is not, though. Even though he only has a few hundred fly balls in this sample, extending it back to 2002 shows the same thing: about half of Rivera’s fly balls are infield flies. No one else is really in the same neighborhood, except for Meredith's fluky looking rate. Halladay has induced more popups than anyone else on this list. So, that’s something else that Halladay is amazing at. Above average strikeouts, groundballs, impeccable control and a little less than half of his flies stay over the dirt.
If you do the math, IFFB/FB looks something like a skill -- certainly more skillish than HR/FB, but considerably less of a skill than strikeout percentage. But the career averages for IFFB/FB are spread far enough apart that you have to think that there is some control that certain pitchers have over it. I don't have pitch selection in this particular data set, but this particular group of names makes me immediately think that having a good cutter is the best way to turn fly balls into popups.
Otis Anderson writes for Bay City Ball, which is part of the SweetSpot blog network.