BABIP and Level

First off all, BABIP is different for pitchers and hitters. 99.5% of MLB pitchers will, over their careers, post a BABIP very close to .300. Even the rare exceptions – Zambrano is one, for example – still keep it relatively close (.284 in his case). Any BABIP significantly (say, 10 points or more) higher or lower than .300 should be assumed to be a complete fluke, unless the pitcher has truly proven that he can keep it that low – or high – over a really long time (and I mean really long – 3-4 seasons at the very east).

With hitters, it is slightly more complicated. Most do stay around .300 for their career, but some can go as high as ~.355, and as low as ~.270. The vast majority still stay somewhere in the .290-.330 zone (for their careers), though.

BABIP can fluctuate tremendously from year to year (let alone month to month), and the fluctuations very rarely mean anything. If a player has one year with a .350 BABIP, and then another with a .290 BABIP, he’s a .320 BABIP hitter as far as you’re concerned. There are some very rare exceptions (usually with players nearing the end of their careers, losing power and speed), but they can be hard to identify. A good why to find underrated players is to pick up players who had low BABIPs for one season – this is what the Diamondbacks did with Kelly Johnson this year, or what the Yankees did with Nick Swisher in 2009.

As for the skills that are likely to lead to a high BABIP – it is fairly intuitive. Fast players will beat out more infield hits. Ground balls go for hits more often than fly balls, and line drives go for hits far more often than either. Power, patience, and an opposite field approach help, too.

The ultimate BABIPer would therefore be a very fast ground ball hitter with a patient, opposite field approach, who hits line drives and has power. Modern science has yet to develop such a creature, but it has gotten very close; we call it “Ichiro”. His career .358 BABIP is the highest among active players, and is one of the many reasons that he is better than you. The anti-Ichiros are guys like Pedro Feliz (.267) and Bengie Molina (.276).

BABIPs are a bit higher in the minors, especially the low minors (because the defense is terrible). Good hitting prospects will usually post high BABIPs in the minors, but they regress to somewhere around league average in the majors. Except when they don’t. But usually they do. As for Joseph’s BABIP – I’d avoid trying to learn anything from the month to month fluctuations. They are almost certainly the result of sheer luck.

Any questions?