ESPN's Peter Keating penned a piece this week assailing the old measure of QBs, passer rating, while touting his company's new metric, QBR. The example he uses is Michael Vick vs Kerry Collins and it's pretty compelling. Here was the passer rating of the two in week one.
Michael Vick: 83.7
Kerry Collins: 82.3
So essentially, the passer rating is telling you that the difference between the games they played was negligible. Only, we know that's not true. Michael Vick was a huge influence in the Eagles win, while Kerry Collins was terrible. Keating took a look at three key differences in the way they played in week one, none of which are factored in passer rating.
1. Rushing yards: Passer rating doesn't include them. And it turns out Vick added 5.8 expected points to the Eagles on running plays, by far the most of any QB in Week 1.
2. Ball-discipline skills: Passer rating doesn't include them, either. And Collins was awful at handling the football.
3. Leverage: Passer rating lumps all passing yardage together, without asking which gains actually make a difference in a game. And Vick had many more attempts when the score was tight, compared to Collins, whose game became virtually hopeless very early on.
When you apply the QBR metric Vick scored an above-average 68.4, while Kerry Collins managed just a 2.3, which was the worst in the NFL in Week 1. You could not have a more dramatic difference and frankly, it's pretty clear that in this instance, QBR was a much better reflection of the reality of how these two played.