Passer Rating vs QBR, Week 1

Learning how they relate to victory.

I've been looking at the NFL age-old Passer Rating stat and ESPN's quarterbacking stat called QBR, which was instituted a decade ago to address alleged shortcomings in the Passer Rating. 

I can sympathize with the desire for something like QBR. Passer rating can shortchange some quarterbacks. For instance, in the 1990s Brett Favre was throwing one-yard touchdown passes while Troy Aikman was handing off to Emmett Smith for one-yard touchdown runs. Favre's TD% may have been inflated, while Aikman may have thrown for more TDs if his team's running game hadn't been so strong. QBR, which evaluates quarterbacks play by play, wouldn't punish Aikman for handing off.

On the other hand, leaders in Passer Rating not only tend to be the winningest quarterbacks, but also the ones we can tell are the best with our own eyes. Some Hall of Famers like Aikman, Joe Namath, Terry Bradshaw, and John Elway may have had average (for their eras) career passer ratings, but their best seasons in passer ratings were also their most successful in terms of winning games and championships.

The correlation of passer rating differential to winning goes back to the early years of the NFL. As Kerry Byrne wrote in 2011,

67 of 69 champions (97 percent) since 1940 finished the year ranked in the top 10 in Passer Rating Differential.

For a little perspective, consider that 68 of 69 champions finished in the top 10 in scoring differential. That's right. Passer rating is nearly as effective at identifying winners as points.

I may get to it someday, but right now I won't go back over the past ten seasons to see if anything's changed. I can't help, however, but think some things changed recently, because:

• Deshaun Watson was 2nd in Passer Rating last year, but his Texans went 4-12.

• Kirk Cousins was 8th (i.e., top 25% of the league), but the Vikings went 7-9.

I dug deeper into Watson's case.

• Although Watson's 112.4 rating is 15th best all-time, in seven games the opposing quarterback had a higher rating. The Texans lost all of them.

• In games where Watson had the edge in passer rating, the Texans were 4-5. The widest passer rating margin he had in defeat was against the Titans, +16.2 as the Texans lost by six. The five losses were all one-possession games, averaging 5 points per loss.

It could be that the Texans' woeful defense was the reason for the anomaly, but I want to examine trends in passer rating each week. In 2021's Week 1:

• The team (combining starters and substitutes, if any) with the higher passer rating went 12-4.

• Teams with a passer rating differential of 50+ (on a scale with 158.3 the perfect score) went 4-0 and won each game by at least two possessions.

• Teams with a passer rating differential of 25-50 went 5-0 with three wins of two possessions or more, and all winning by at least 4 points (i.e., more than a field goal).

• Teams with a passer rating differential of 0-25 went 3-4. All seven were one-possession games, including two overtimes (1-1). The largest margin was the Patriots' 23 over the Dolphins, a game the Pats lost by a point. The next-largest was the Bengals' 22, and their victory over the Vikings was in overtime.

Passer rating differentials of 22-23 seem significant. If these games are tossups, perhaps passer rating isn't quite as reliable a predictor of victory as it used to be. 

Now let's see the QBR results of Week 1.

As with passer rating, the teams with the higher QBR went 12-4. 

• Tom Brady, Derek Carr, and Tua Tagovailoala all had both lower passer ratings and lower QBRs than their counterparts but still won.

• Ben Roethlisberger had a higher passer rating but lower QBR than his counterpart and won. In contrast, Justin Herbert had a worse passer rating but higher QBR than his counterpart in a victory.  

• The QBR differentials in the 4 losses (on a 100-point scale) are 28.3, 11.9 5.8, and 4.5; all games were close.

I'm looking forward to collecting more data throughout the season to see if passer rating or QBR is a clearly superior statistic.  

James Leroy Wilson writes from Nebraska. Follow him on Facebook and Twitter. If you find value in his articles, subscribe and exchange value for value. Your support through Paypal helps keep him going. You may contact him for your writing, editing, and research needs: jamesleroywilson-at-gmail.com.

For Wilson's insights into the news, society, and spirituality, subscribe to JLCells.