Yeah I don't know the answer but I agree with MJ. It's a problem with the small samples involved with relievers.

Put it this way. Parnell has 198IP or basically one starter season (a long one, granted). Now obviously, SPs have had flukishly high or low BABIPs over a single season. So in that sense, I can't be all that confident calling Parnell's BABIP his true talent level.

This is pretty much what I've been saying for awhile; the sample size isn't big enough to conclude anything. It just appears big because it's over multiple years since he's a reliever.