It’s complicated, I know. Here’s how you calculate the NFL Passer Rating statistic.
Each year. I write a column at this time of the season about the NFL’s Passer Rating Formula–altering it slightly to reflect current trends.
There’s a good reason to understand how this formula is calculated, too. Just as baseball observers have complained that expansion has diluted the amount of quality pitching, the same could be said about the NFL and NFL quarterbacks. Here’s proof.
In 2008, there was but one quarterback—the Chargers’ Philip Rivers—who notched a season-long passer rating higher than 100. Eight years later, there were five quarterbacks with appreciable playing time who surpassed that figure. Twelve additional signal-callers broke the 90-barrier. Through Week 7 this year, five quarterbacks have a rating of 100 or higher, and five more are at 90 or better.
With 158.3 denoting a perfect passer rating, it means that quarterbacks are closer to perfect than they’ve ever been. Two quarterbacks have posted single-game perfect ratings this year: Baltimore’s Lamar Jackson in Week 1 and Green Bay’s Aaron Rodgers in Week 7.
In recent years, ESPN has unveiled the QBR, a system that’s weighted so that 100 is the number for a perfect rating. But since the league does not recognize ESPN’s scale, we’ll go with the NFL system.
The great Bart Starr (photo, Ernest Anheuser)
As I was writing this piece, it dawned on me that we could be heading for a return to the days when teams face future Hall of Fame quarterbacks every week. If that happens, then teams would be concerned—if not downright fearful—that they would be victimized by the tenacity of a Roger Staubach or John Unitas … the arm of a Sammy Baugh or Bart Starr … or the accuracy of a Len Dawson or Otto Graham.
But none of those quarterbacks–or any of their contemporaries–had to worry about ‘passer ratings.’ That’s because the formula didn’t exist until 1973.
But I’m not sure the oft-maligned statistic should be called a “quarterback” rating, either. Why? It doesn’t measure leadership and all the other intangibles unique to that position. That said, it’s the only ‘official’ composite indicator we have to measure/compare quarterbacks. And that makes it meaningful for fans, coaches, and general managers as they evaluate NFL QB’s.
But it’s a convoluted way to get there, requiring a sharp mind, a penchant for numbers, and a lot of patience. So here we go!
1. The Passer Rating is compiled of four primary stats: % completions, touchdown passes, interceptions per attempt, and average gain per attempt. The highest number a QB can achieve in any of those four categories is 2.375.
Manning in 2004 (photo, Blue Stampede)
2. Subtract 30 from the Completion Percentage and multiply that number by .05. If you get a number less than zero, then the number for that part of the formula is zero. If the result is more than 2.375, then that is the assigned number. Note: The league likes to use Peyton Manning’s 2004 season as an example. IN 2004, Manning completed 67.6% of his passes. When the above formula is applied, the result is 1.880.
3. Subtract 3 yards from the Average Yards per Pass and multiply that number by .25. In 2004, Manning threw for 4,557 yards on 497 attempts. That’s 9.17 yards per attempt, which, when Step 3 is applied, turns into 1.543.
4. Multiply the Touchdown % by 0.2. As in Step 2, if the result is greater than 2.375, then that is the number assigned. But that wasn’t the case with Manning. His most productive year featured 49 touchdown passes out of 497 throws. The touchdown percentage is 9.86 percent, which turns into 1.972.
5. Multiply the Interception % by 0.25 and, then, subtract the resulting number from 2.375. If the result is less than zero, then zero is the resulting number for this step. Manning threw ten interceptions out of 497 throws, which calculates into a 2.01 percent reading. Applying Step 5, the result is 1.872.
6. Take the resulting numbers from Steps 2-5 and add them together. You will get 7.267.
7. Divide the Step 6 result by 6 and, then, multiply the result by 100. Using our Manning-based data, that means Manning’s Passer Rating in 2004 was a gaudy 121.1.
Yes, it’s complicated, I know, and not for the faint of heart. It’s downright scary. That’s why I ask TSC to publish my updated version each year at Haloween time.
Joe and Aaron
“No, Aaron, it’s not about me. The only thing I did was explain it. YOU ACTUALLY DID IT!”
(158.3 Passer Rating, 2019 Week 7)
