The NFL's Passer Rating statistic has always been controversial. Its critics claim it doesn't account for the true efficiency of a team's passing game because it ignores sacks (and yards lost from sacks). It also has curiosities. For example, a 77.5 completion rate is as good as a 100% completion rate. At The Data Jocks, writer jdashbrock noted, "Two players with vastly different stats – one could even be noticeably better than the other! – can be labelled as both having perfect games by passer rating."
Nevertheless, Passer Rating has historically been shown to correlate with team success. In 2011 Kerry Byrne reported that Passer Rating differential (a team's offensive passer rating minus its defensive passer rating) is almost as reliable as scoring differential in identifying winners.
I kept track of passer ratings during most of the 2021 season, discovering that the team with the higher passer rating in the game won 79.6 of the time. Teams that won the turnover battle won 79.2% of the time during the same span. I speculated (with the confidence of common sense) that interceptions were the key factor in both stats.
I've wondered how to compare passers from different eras who operated under different league rules and playbook schemes. For instance, the league average passer rating in 1974 was 64.2; in 2024 it's 91.9. The best of the best from decades ago had far worse passer ratings than they do now simply because it was more difficult to throw the ball. Is there a way to compare them?
There is. Last week I discovered the Passer Rating Index. In short, in any era, the average passer rating is adjusted to 100, and one standard deviation above average is 115. A Passer Rating Index of 115 in a given year typically meant that the passer was among the top five or six in Passer Rating in that season. Above 100 might be slightly above average, good, or very good; above 115 is elite.
Using Stathead, I looked at all players that had at least one season with a Passer Rating Index (PRI) of 115 since the NFL's inception. 26 players had a PRI of 115+ in five seasons or more. They are listed in descending order with the number of seasons beside the name. Where the number of seasons is the same, the players are listed alphabetically.
GREATEST PASSERS OF ALL TIME
Drew Brees 12
Peyton Manning 12
Fran Tarkenton 10
Tom Brady 9
Joe Montana 9
Aaron Rodgers 9
Len Dawson 8
Brett Favre 8
Johnny Unitas 8
Russell Wilson 8
Steve Young 8
Dan Fouts 7
Otto Graham 7
Bob Griese 7
Dan Marino 7
Y.A. Tittle 7
Ken Anderson 6
Sonny Jurgensen 6
Philip Rivers 6
Ben Roethlisberger 6
Bart Starr 6
Roger Staubach 6
Warren Moon 5
Craig Morton 5
Carson Palmer 5
Tony Romo 5
Several quarterbacks have had a PRI of 115+ four times, from Ken Stabler to Boomer Esiason to Kirk Cousins. Earl Morrall reached the mark for four different teams. Patrick Mahomes has reached 115 four times so far but won't in the 2024 season. That even Mahomes has reached it in "only" half the seasons he's played so far speaks to how difficult it is to attain a PRI of 115.
This "Greatest Passers" list isn't a "Greatest Quarterbacks" list. Other factors, including Pro Bowl selections and playoff success, would contribute to a greatest quarterbacks list.
For instance, John Elway had a PRI of 115 or more "only" three times in his career, as did Terry Bradshaw and Troy Aikman. They have a combined eighteen Pro Bowl selections and nine Super Bowl wins, so being great in Passer Rating throughout one's career isn't necessary to be considered a great quarterback.
That said, almost all of the greatest quarterbacks are on the above list of greatest passers.
James Leroy Wilson writes The MVP Chase (subscribe). Thank you for your subscriptions and support! You may contact James for writing, editing, research, and other work: jamesleroywilson-at-gmail.com.