View Full Version : NFL quarterback ratings don't add up

09-22-2006, 12:48 PM
The math isn't necessarily Bernoullian.

In fact, it is a simple formula, with no more complicated mathematical operations than addition, subtraction, multiplication and division.

Yet if the goal were to crinkle the brow of a quarterback or coach, just politely ask one to provide the passer efficiency rating formula.
"Hell no," Texans coach Gary Kubiak said when asked if he knew how the number is ascertained.

It is the hot dog of football statistics, but not only do few know what goes into calculating it, not many understand or like the finished product.
In the NFL — after you subtract 30 from a player's completion percentage and multiply that by 0.05, subtract three yards from his yards-per-attempt and multiply that by 0.25, multiply his touchdown percentage by 0.2, multiply his interception percentage by 0.25 and subtract that from 2.375, add the four results, divide that result by six and multiply it by 100 — a perfect passer rating is 158.3.

(Yes, you and Theo Huxtable, you should have paid more attention in Mrs. Westlake's class.)

"It's the dumbest scale known to mankind," said Aaron Schatz, the editor-in-chief of FootballOutsiders.com, a Wweb site dedicated to in-depth analysis of NFL statistics. "Nobody understands what it means. Why couldn't they have made it from zero to 100? Would that have been so hard?

"You don't want to look at a number and have to do the math; you want somebody else to do the math and you look at the number."

Matters not where the number comes from, Kubiak likes knowing that through two games this season his quarterback has the second-highest rating in the NFL. Statistically, David Carr could not be off to a much better start, having thrown four touchdowns and no interceptions, with an astounding completion percentage of 75.5. (He entered the season with a career average of 57.8 percent.)

He has an efficiency rating of 123.7, just behind the Chicago Bears' Rex Grossman (128.7).

"I've never been around a quarterback with that type of number, period," said Kubiak, whose career passer rating was 77.3 in eight seasons as a quarterback with the Denver Broncos. "It's a heck of a number."

Expect that number to work its way downward through the season. The NFL's season record for pass efficiency is 121.1, set by Peyton Manning in 2004. Manning has more perfect games in the regular season (three) than any quarterback since the league introduced the formula in 1973. Steve Young, who spent the majority of his career with the San Francisco 49ers, holds the highest career passer rating (96.8), and the Arizona Cardinals' Kurt Warner has the best mark among active players (94.2).

Interestingly, Kubiak was the offensive coordinator in San Francisco when Young set the then-NFL record for passing efficiency at 112.8 on his way to the MVP award in 1994. That mark remains No. 2 all time.