Passer rating

Before the development of the passer rating, the NFL struggled with how to crown a passing leader. In the mid-1930s, it was the quarterback with the most passing yardage. From 1938 to 1940, it was the quarterback with the highest completion percentage. In 1941, a system was created that ranked the league's quarterbacks relative to their peers' performance. Over the next thirty years the criteria used to crown a passing leader changed several times, but the ranking system made it impossible to determine a quarterback's rank until all the other quarterbacks were done playing that week, or to compare quarterback performances across multiple seasons. In 1971, NFL commissioner Pete Rozelle asked the league's statistical committee to develop a better system.[3] The committee was headed by Don Smith of the Pro Football Hall of Fame, Seymour Siwoff of the Elias Sports Bureau, and NFL executive Don Weiss. Smith and Siwoff established passing performance standards based on data from all qualified pro football passers between 1960 and 1970, and used those data to create the passer rating. The formula was adopted by the NFL in 1973.[2]

The NFL passer rating formula includes four variables: completion percentage, yards per attempt, touchdowns per attempt, and interceptions per attempt. Each of those variables is scaled to a value between 0 and 2.375, with 1.0 being statistically average (based on league data between 1960–1970). When the formula was first created, a 66.7 rating indicated an average performance, and a 100+ rating indicated an excellent performance.[3] However, passing performance has improved steadily since then and in 2017 the league average rating was 88.6.[4]

The four separate calculations can be expressed in the following equations:

${\displaystyle a=\left({{\text{COMP}} \over {\text{ATT}}}-.3\right)\times 5}$

${\displaystyle b=\left({{\text{YDS}} \over {\text{ATT}}}-3\right)\times .25}$

${\displaystyle c=\left({{\text{TD}} \over {\text{ATT}}}\right)\times 20}$

${\displaystyle d=2.375-\left({{\text{INT}} \over {\text{ATT}}}\times 25\right)}$

where

ATT = Number of passing attempts

COMP = Number of completions

YDS = Passing yards

TD = Touchdown passes

INT = Interceptions

If the result of any calculation is greater than 2.375, it is set to 2.375. If the result is a negative number, it is set to zero.

Then, the above calculations are used to complete the passer rating:

${\displaystyle {\text{Passer Rating}}=\left({a+b+c+d \over 6}\right)\times 100}$

The NCAA passing efficiency formula is similar to that of the NFL passer rating, but does not impose limits on the four components:[5]

${\displaystyle {\text{Passer Rating}}_{\text{NCAA}}={(8.4\times {\text{YDS}})+(330\times {\text{TD}})+(100\times {\text{COMP}})-(200\times {\text{INT}}) \over {\text{ATT}}}}$

where

ATT = Number of passing attempts

COMP = Number of completions

YDS = Passing yards

TD = Touchdown passes

INT = Interceptions

The NCAA passer rating has an upper limit of 1,261.6 (every attempt is a 99-yard completion for touchdown), and a lower limit of −731.6 (every attempt is completed, but results in a 99-yard loss). A passer who throws only interceptions will have a −200 rating, as would a passer who only throws completed passes losing an average of 35.714 yards.

In 2011, Sports Illustrated published an article by Kerry Byrne of Cold Hard Football Facts highlighting the importance of passer rating in determining a team's success.[6] "Put most simply," the article states, "you cannot be a smart football analyst and dismiss passer rating. In fact, it's impossible to look at the incredible correlation of victory to passer rating and then dismiss it. You might as well dismiss the score of a game when determining a winner. [...] Few, if any, are more indicative of wins and losses than passer rating. Teams that posted a higher passer rating went 203–53 (.793) in 2010 and an incredible 151–29 (.839) after Week 5." Byrne made an expanded defense of the passer rating and its importance for the Pro Football Researchers Association in 2012.[7] The study showed that all of the eight teams since 1940 that led the league in both offensive passer rating and defensive passer rating won championships.[8]

• List of NFL quarterbacks who have posted a perfect passer rating
• List of NFL quarterbacks who have posted a passer rating of zero
• NFL career passer rating leaders
• List of National Football League season passer rating leaders
• Total quarterback rating
• Blutarsky

• NFL.com QB Rating Page
• Online passer rating calculator for NFL/CFL, NCAA and AFL formulas
• A look at and breakdown of the NFL Passer Rating
• NFL Career Passer Rating Leaders
• QB Rating Calculator
• Adjustable NFL passer rating calculator and database. Stats from 1932 – present.
• New York Times – The N.F.L.'s Passer Rating, Arcane and Misunderstood – January 14, 2004