Anyway OPs title is relevant and I'd like to know the answer. I don't want to mock QBR metric, I would like to know how it works. If often doesn't match eyetest or raw statistics, and this 49ers game seems like a prime example. It seems really hard to do more than JA did. Is it so low because of that Moss fumble? Or because Allen's "fumble" recovered by Dawkins which wasn't?
Josh had better QBR 5 games this season and 13 games in his career.
So anybody has a clue how they count it and what is the reason for it to be so low this time?