Good question in the comments section from Los Angeles Rams of St. Louis regarding dropped passes: What constitutes one, exactly?
2011 Drops Through Week 3
Hank Gargiulo of ESPN Stats & Information passed along the written standard our game charters rely upon to reduce subjectivity.
This standard says drops are "incomplete passes where the receiver SHOULD have caught the pass with ORDINARY effort."
Basically, we're talking about blatant drops, not the ones where your old man leans over and says anything that grazed the receiver anywhere was a drop in his day.
"Only use this if the receiver is 100 percent at fault and no one else can be blamed for the incompletion," ESPN tells its game charters. "Pass interference that wasn't called/passes thrown just outside the receiver's reach, etc., are NOT drops."