Boo! Don't Be Scared Of The Passer Rating Formula
MANY COMPLEX PARTS TO FORMULA
By Joe Platania
(NOTE: Each year at this time, we run the following column about the NFL's passer rating formula, slightly altered to reflect current trends. Because it's almost Halloween, we ask you not to be scared of the complicated process that goes into it. But because we get plenty of questions about it year-round, we haul it out annually. -- JP)
Let's face it. It's a scary time of year.
It's not just because Halloween is coming Wednesday, although that certainly doesn't help.
Decorations, candy, costumes and other ancillary items are making this annual fall observance more expensive than ever.
(What, you thought we meant ghosts, goblins and blood? That's mere child's play, the stuff of healthy, youthful role-playing fantasy, no matter what the overzealous, politically correct crowd says.)
No, what makes this portion of the calendar most perilous are the dangling playoff fortunes of the many NFL teams that may think they are contenders, but truly aren't.
What leads to such uncertainty? The league-wide passing game explosion, that's what.
Just as baseball observers have endlessly complained that expansion has diluted the amount of quality pitching throughout the sport, the same could be said of the depth of NFL defenses falling victim to the gaudy passing numbers being posted.
In 2008, there was but one quarterback -- the San Diego Chargers' Philip Rivers -- who notched a season-long passer rating higher than 100. Four years later, there are currently three quarterbacks that can claim that figure, as well as nine additional signal-callers that have broken the 90 barrier through seven regular-season weeks.
With 158.3 denoting a perfect passer rating, that means that more so than ever, more quarterbacks are closer to perfect than they have ever been.
We could be heading for a return to the days when teams would be facing future Hall of Fame quarterbacks every week, 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.
None of the above, or any of their contemporaries, truly cared much for statistics such as the modern-day implementation of the passer rating (1973).
But today, the oft-maligned statistic -- which is not called a "quarterback" rating because it doesn't measure leadership and other intangibles unique to the position -- means just about everything for those fans, coaches and general managers who evaluate talent and need an all-encompassing number to see where someone stands.
For years, many have asked how a passer rating is compiled. It is a convoluted process requiring an analytical mind, strong batteries in the calculator and a lot of patience.
If you're ready to take a trip into this shadowy, haunted world, here we go ... and try not to scream:
1. First, it's important to know that the passer rating is compiled of four main stats: percentage of completions, touchdown passes, interceptions per attempt and average gain per attempt.
The highest number a passer can achieve in these four categories -- through the formula you will see in a few moments -- is 2.375.
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 this section is zero. If the result is more than 2.375, then that is the number assigned.
The league likes to use Peyton Manning's 2004 season as an example in these matters. Manning completed 67.6 percent of his passes that year. When the above formula is applied, the result is 1.880. Keep that number handy, for it will be needed later.
3. Subtract 3 yards from the average yards per pass and multiply that 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. Again, that number will become more important in a few minutes.
4. Multiply the touchdown percentage 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, whose biggest year ever featured 49 touchdown passes in 497 throws. The touchdown percentage was 9.86 percent, which turns into 1.972.
5. Multiply the interception percentage by 0.25 and 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 10 interceptions in his 497 throws for a 2.01 percent reading. Applying Step 5, the result is 1.872.
6. Take the resulting numbers from Steps 2 through 5 and add them together. You will get 7.267.
7. Then -- if your brain hasn't exploded by now -- divide the Step 6 result by six and multiply that result by 100. You should have come up with Manning's passer rating for 2004, 121.1.
We hope you've now learned not to be afraid of the passer rating. But if you're still fearful of quarterbacks like Manning, we can't help you there.
After all, it's a scary time of year.
Posted Oct. 26, 2012