In a recent conversations with another football enthusiast, the topic of the passer rating became a subject of great disgust. Most of us, even the most ardent football fans among us, could not tell you how this extremely confusing, mysterious and well-muddled statistic is calculated or WHY a perfect passer rating is 158.3 and not 0 (the perfect ERA for a pitcher in baseball) or 1.000 (for hitters in baseball). So I researched it a little.  Here is what I found:

Calculations

The passer rating is calculated by the following formula (I’m not making this up):

[((completion/attemptions*100)-30)/20] + [(yards/attempts - 3)/4] + [# of touchdowns/attempted X 20] + [2.375 - ((interceptions/attempts)*25)]

 
 

then, the answer is divided by 6 and then multiplied by 100.  If an individual value – inside the square brackets – is less than 0, it is 0 for calculations.  If it is greater than 2.375, it is still 2.375. 

 

This may sound bogus and ridiculous, but I assure you this is the way they calculate it. 

Tom Brady, Week 1

I will use Brady’s week 1 game against the Jets as an example.

  • Completions = 22
  • Attempts = 28
  • Yards = 297
  • TD = 3
  • Interceptions = 0

So his passer rating was 146.6 because…

 
 

[((22/28*100)-30)/20] + [(297/28 - 3)/4] + [3/28 X 20] + [2.375 - ((0/28)*25)] / 6 * 100 

Ben Roethlisberger, Week 15

In order to illustrate how absurd this is, I will now pull out the numbers for Ben Roethlisberger’s “perfect game” a couple of weeks ago on Thursday night.  As we have been reminded…repeatedly…Roethlisberger got a perfect passer rating.  Here are his stats: 

  • Completions = 16
  • Attempts = 20
  • Yards = 261
  • TD = 3
  • Interceptions = 0

 [((16/20*100)-30)/20] + [(261/20 - 3)/4] + [3/20 X 20] + [2.375 - ((0/20)*25)] / 6 * 100

 
 

Although statistically, the two were pretty much equal (Brady had 36 more yards but Roethlisberger’s completion percentage was 1.4% higher), Roethlisberger gets a higher score.

Tom Brady’s Perfect Game

Now consider Brady’s “perfect” game from Week 7.

  • Completions = 21
  • Attempts = 25
  • Yards = 354
  • TD = 6
  • Interceptions = 0

Ahh, Grading on the Curve

Although Brady’s game was FAR superior to Roethlisberger’s in EVERY WAY, they both had “perfect” games.  WHY? Because the system is a great example of a sliding scale. 

When Don Smith devised the system in 1973, the idea was that the worse you did, your rating declined faster.  Of course, Smith assumed 66.667 as the average score and created a system around that score.  The problem is that the average rating in 2003 was 78.9, and in 2004 (thanks to Peyton Manning, Tom Brady, and a few others) it was 82.8. 

In short, the passer rating is entirely meaningless and has no value whatsoever.  If two quarterbacks can have games just a few weeks apart where one (Tom Brady) out throws the other (Roethlisberger) by nearly 100 yards and doubles the number of touchdowns, and the two have identical passer ratings…then the ratings system is flawed.