There was some talk earlier about Derek Jeter's insanely high batting average on balls in play (BABIP) since returning from the disabled list earlier today in the open thread. After reading it, I decided to take a deeper look into Jeter's return.
According to WWJD, as of two days ago, his BABIP since returning from the disabled list is .404, which is 0.071 points higher than his 2011 BABIP (.333) and 0.049 points higher than his career average BABIP (.355). So, what is driving this increase over the last two months in his BABIP? Could it be luck?
I don't think so. My answer? Line drives, and to a lesser extent, ground balls.
According to Dave Studeman of The Hardball Times, line drives fall for a hit about 74% of the time, and batters will get a hit on a ground ball about 28% of the time. Fly balls have the lowest BABIP at about 21%. With that in mind, we expect a BABIP to be a player's line drive percentage + .120.
In July, Jeter's line drive percentage was 19.7, and in August, his line drive percentage is currently a massive 34.9.
With those numbers, what should his BABIP be? Let's examine July and August. Remember that expected BABIP is line drive percentage +.120.
In July, Jeter had a .343 BABIP. With a 19.7 line drive percentage, his expected BABIP was .317. His actual BABIP could have been higher due to luck, but I think it may have more to do with the large amount of ground balls Jeter hits (64.8% grounders, 15.5% flyballs in July, 8.7 infield hit percentage).
In August, Jeter has a BABIP of .464. With a 34.9 line drive percentage, his expected BABIP is .469, right in line with his August BABIP.
No matter how we try to swing the numbers around, Jeter has been really good since returning from the DL. There is no way he will be able to continue hitting line drives at a 34.9% clip, as he will eventually regress, but watching Jeter hit right now is a lot of fun.
Numbers from fangraphs.