Expanded Four Factors: Austin Jackson’s BABIP by Jack Moore August 12, 2010 Expanded Four Factors links: Aaron Hill Ryan Howard Average Player Math/Reference Yesterday afternoon, I took a look at Aaron Hill and his abnormally low BABIP. Naturally, today we will be taking a look at Austin Jackson, who leads all qualified hitters with a .422 BABIP. That’s 29 points above the second highest BABIP, Josh Hamilton’s .393, and 123 points above the MLB average of .299. As with Hill, Jackson’s profile does suggest that he should have an above average BABIP. He has a line drive rate of 25.8% and a ground ball rate above 50%, and both serve his speed quite well. As such, an above average BABIP should be expected. But there are limits. First of all, Jackson’s high line drive rate is second in the league and ripe for some amount of regression to the mean. Second of all, Jackson’s BABIP on ground balls in particular is .333, and bound to come down. Jackson’s excellent 10.1% infield hit rate is about 4% above the league average, meaning that he accrues an extra 5.5 hits among his 148 ground balls, which only accounts for about 30 points of BABIP on grounders – that .333 GB BABIP is over 100 points above the league average rate, and can’t simply be explained by speed. His BABIP on fly balls is also above the league average, by just under 70 points, and I don’t think the abnormality on fly ball BABIP can be explained as simply as his speed. Simply put, Jackson’s BABIP is going to come down. He has a .342 wOBA this season, which, after taking out the SB/CS component (16 SB, 4 CS), comes closer to his Four Factors-projected .335 wOBA. Right now, Jackson is below average in the other three non-BABIP components, with a 6.2% BB%, a 26.1% K% (K/PA), and a .334 POWH (XB/H) to go along with that .422 BABIP. Let’s take a look at what happens when that BABIP starts moving down toward the mean. To account for the fact that Jackson is 23 and could easily improve, I have included a forecast for a 4% decrease in K% (in blue), along with a forecast for the same K% as this season (red). In the optimistic projection, a drop to a more realistic .350 BABIP (think Ichiro level) has Jackson as a .300 wOBA player – as well as Aaron Hill has hit with his .199 BABIP. In the pessimistic projection, that same drop would make Jackson a .287 wOBA player – think Carlos Gomez. In fact, given both players’ fantastic defensive abilities, they make decent comps. The depressing part here is that any BABIP below .380 – something I think is a mortal lock for the future – leaves Jackson as a below average hitter in either scenario, which isn’t necessarily a bad thing. Even if Jackson isn’t a terrific, or average, or even competent hitter, he has fantastic defense in center field to fall back on, which could easily make him a league average player. His minor league numbers don’t particularly suggest an incoming increase in contact skills, walk rates, or power, however, so Tigers fans will likely have to be content with a light hitting, slick fielding center fielder under team control for a long time. And really, that’s not so bad.