posted by gut
It's garbage. It's not scientific, at all, and you simply can't run those metrics without knowing the playcall, watching the All-22 footage, and adjusting for the opponent.
Football Outsiders is far superior. DVOA isn't perfect, and it's a little early in the season. Unfortunately, it's now a subscription. And, LOL, I see they just last week they had BUF back to #1 in DVOA. Like I said, it's a bit early for it to converge to reality.
They are far from perfect, but they are very good for specific positions. O-Line and Secondary, in particular. They do watch the All-22, and study each player individually on each play. They don't take into consideration the opponent, but they are grading players on their individual performance. Opponent doesn't really matter. Play call matters, but kinda impossible for anyone to get that data. But also goes to the point of why they are so good for O-Line and secondary. They can judge those guys off of Pass/Rush/Play-Action. The rest of the play has some influence, but thats a solid starting point.
My biggest problem with them may be how dumb a lot of them are as individuals. I dont think that really matters for their job performance, but I cant help but be a skeptic on it.