We know Dallas ranks 14th in (traditional) defensive pass rating. IOW, opposing QB have a 91.4 rating against our defense. Last year, we were 26th.
For every offensive stat, there's a corresponding defensive stat, so it's very strange that there's no such thing as defensive QBR. Not only would it be interesting to compare Dallas' defenses the last two seasons, but it would also allow us to see how the stat correlates to W-L. Right now, we just have one half of the equation. Two QB with identical QBR wouldn't necessarily have similar W-L records, because the QB their defenses face also have QBR of their own which (by definition) have to count just as much.
This has been posted before for those that cared to read it.
Q. Does QBR relate to winning?
A. How QBR "relates to winning" is a question that can be interpreted various ways. One way that we addressed this on TV was that the team winning the QBR battle within a game wins the game 86% of the time. Teams that win the turnover battle don't win this often. Teams that win the NFL Passer Rating battle don't win this often. This result is primarily emphasizing that QBR is capturing team results and that quarterbacks performance is quite important to that.
But QBR is not meant to be a perfect indicator. A quarterback affects the offense, so a quarterback with a good defense doesn't have to be as good. What illustrates this are the 2008 seasons of Ben Roethlisberger of the Pittsburgh Steelers and Dan Orlovsky of the defenseless Detroit Lions. Orlovsky had a Total QBR value of 51, whereas Roethlisberger posted just a 46 (but a 61 in the playoffs that people remember).
In that year, expected points allowed by team defense had the Steelers second in the NFL and the Lions dead last, with more than 300 points difference on the defensive side of the ball. With that kind of defensive difference, it was possible for Orlovsky to have a better rating than Roethlisberger and still lose a lot more. Orlovsky wasn't terrible either. In the 7 games that Orlovsky started for the Lions, the team offense was about average by expected points added; in the other 9 games, they were roughly 10 points per game worse. In the games started by Roethlisberger, the Pittsburgh team offense was about the same as the Orlovsky-led Lions offense.
So QBR is meant to correlate to offense, moving the ball downfield, turning good field position into points, avoiding giving it back to the defense. Good offensive performance is not the same as winning. To the degree that offense correlates to winning, QBR should be helpful.
