PFF has a systemic issue. Football isn't baseball. You can't isolate one batter against one pitcher and get a pretty good idea of the skills of both players.



PFF would say you can. That you can focus on the LG vs the RDT, see who gets the better of the match-up, and then assign an "objective" grade to the outcome.



Coaches aren't stupid. They don't, generally, ask players to do things they can't do. So you may find that both LGs involved in a game blew four run blocks and two pass protections, so they get the same grade. The problem is that one of those LGs is an all-pro and was being asked to make difficult reach blocks all game, while the other is a stump who just slowed down the guy in front of him.



The same thing is true at other positions. Good RTs are going to be left to block alone more often than bad ones. Great quarterbacks will be asked to make more difficult throws. TEs who are abysmal at blocking won't do it very often.



By atomizing performance we're ignoring the way 11 players on a side function as a system that gets continually re-balanced to achieve some sort of equilibrium.



Another example: Playing defense gets easier and easier the better your teammates are. Take one MIKE who's playing behind two dominant DTs. That guy's going to look like an all-pro as he's running around clean knocking heads. Put that same MIKE on another team with a Swiss cheese line and now his job will be much harder. Same for CBs playing Ss and, really, the whole back seven playing with a good or bad pass rush.



None of this would matter as much if ...