I just saw this interesting article written by Football Outsiders after week 14 of the season (so while the data is not complete, its pretty close), discussing QB interceptions.  The premise is to come up with a total (or rate) of interceptions a QB "should" have thrown.  Added to the QB's total is "dropped INTs", basically passes that should've reasonably been caught by the defense.  Subtracted from the QB's total is hail-mary INTs and tipped passes INTs that should have been caught by the receivers. 

http://www.footballoutsiders.com/extra-points/2010/fo-mailbag-dropped-interceptions

Eli is credited with three tipped INTs (while cutoff routes are not tallied... i'm looking at you Nicks), and only 2 dropped INTs... as compared to Sanchez's 13 dropped INTs.

It doesn't mean a lot except put some of it in perspective with a little more context.  Its possible you could use data like this to predict that Sanchez will have a reasonable decline next year, since he halved his INT rate from his rookie campaign, but got really lucky with the dropped INTs.  Similarly I'd expect a bounceback season for Eli next year, and in context his year wasn't quite as bad as we initially thought.  Not that being 5th on this list is good, at all... but he is behind greats like his brother and Brees.