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Rollins’ Horrid BABIP

Jimmy Rollins is having a pretty bad year at the plate, with a wOBA of .316. Before this year, going back to 2004, he has had a wOBA of at least .341, and had four years above .350. That was very good offensive performance for a shortstop. Not a big walker, the offensive value came from contact skills, a good BABIP and solid power. Well, this year the second of those three fell out from under him. His BABIP dropped to 0.253 taking his batting average and on-base percentage (under .300) with it.

For a speedy switch hitter, often batting from the first base-side batting box, a BABIP of 0.253 is surprisingly low. In fact, it is the third lowest in the game, down with guys like Carlos Pena, Aubrey Huff, David Ortiz and Bengie Molina. His IFFB% is 13.7%, thirteen in the league, and that probably plays some role, but there has to be more to it. To look deeper I went to Baseball Reference which breaks up BABIP by hit type. Here they are for Rollins’ career, for Rollins in 2009 and the NL 2009 average.

|              |  Career |    2009 | Average |
| Ground Balls |   0.225 |   0.213 |   0.235 |
| Fly Balls    |   0.095 |   0.094 |   0.142 |
| Line Drives  |   0.725 |   0.629 |   0.718 | 

It looks like the big issue is with his line drives. They are falling for hits way less often than in his career or league average. He has 118 line drives this year. If he had his career average BABIP on those he would pick up about 10 extra hits, which would bring his BA up to .263 and his OBP .304. Better, but still off his career numbers.

To look at this a little closer I plotted the heavily smoothed frequency distributions of the angles in play of his line drives for 2009 versus 2005 to 2008 (the years the data are available from GameDay).


It does look quite different. He is hitting many more to right field; in addition, these are turning into outs much more frequently.

BABIP on Line Drives
|          |  Career |    2009 |
| Angle < 0|   0.707 |   0.650 |
| Angle > 0|   0.784 |   0.620 |

Usually the line drives he hits to right field fall in for hits at a very high rate. This year he is actually hitting more to right field, but they have a much lower BABIP.

Even breaking the data down this far it is still hard to say how much of this is bad luck and how much of it is something wrong with Rollins. As Jack talked about earlier today, this is a place where the HITf/x data would really come in handy.