The Consistency of NFL Quarterbacks

By
Updated: January 24, 2013

Introduction

Football announcers are fond of saying that an outstanding quarterback is “consistently excellent” — or conversely bashing an underachieving quarterback by saying he “needs to improve his consistency.”

Based on comments like this, there seems to be a prevailing theory out there that the elite quarterbacks in the NFL are separated from the pack by their consistency.  Do the statistics back this assertion up?  Let’s dive in and take a look.

"Let me tell you something: this guy is so good because he's consistent." But is that a true statement?

“Let me tell you smething: this guy is so good because he’s consistent.” But is that true?

Because we here at the WCSN are born iconoclasts, I just had to dig into this and see if there was any truth to the conventional wisdom. This is the first installment of a two-part series in which we examine the consistency of NFL quarterbacks. This installment will explore league-wide trends, while the second part will focus on the four NFC North quarterbacks.

To the statsmobile!

Numbers and tables

To find the simplest method possible of measuring quarterback consistency, I looked at the standard deviation of game-by-game passer ratings for quarterbacks in the last two years. Ignoring playoff games, I included only quarterbacks who made at least 20 regular-season starts for the same team between 2011 and 2012. A total of 24 players qualified for this study. These numbers were chosen to find the best middle ground between getting a large enough pool to do a meaningful study and having a large enough sample size for each individual to get meaningful results.

The table below shows the 24 quarterbacks examined, along with their passer rating over the last two years and the standard deviation of their single-game passer ratings. A lower standard deviation means there is less variability — or in other words, that a quarterback is more consistent. NFC North quarterbacks are labeled in bold.

Quarterback Team RTG STD
Sam Bradford St. Louis Rams 77.8 18.0
Tom Brady New England Patriots 102.0 20.5
Aaron Rodgers Green Bay Packers 114.9 20.5
Matt Hasselbeck Tennessee Titans 82.0 20.8
Blaine Gabbert Jacksonville Jaguars 70.2 21.4
Michael Vick Philadelphia Eagles 81.8 22.6
Ben Roethlisberger Pittsburgh Steelers 93.3 22.8
Carson Palmer Oakland Raiders 83.5 22.8
Ryan Fitzpatrick Buffalo Bills 81.0 23.4
Matthew Stafford Detroit Lions 88.1 23.5
Andy Dalton Cincinnati Bengals 83.9 23.6
Joe Flacco Baltimore Ravens 84.3 24.6
Eli Manning New York Giants 90.2 25.8
Josh Freeman Tampa Bay Buccaneers 78.1 26.0
Drew Brees New Orleans Saints 103.4 26.1
Mark Sanchez New York Jets 73.0 27.1
Christian Ponder Minnesota Vikings 77.1 27.2
Philip Rivers San Diego Chargers 88.7 27.3
Cam Newton Carolina Panthers 85.3 27.3
Tony Romo Dallas Cowboys 95.8 28.0
Matt Ryan Atlanta Falcons 95.8 28.6
Matt Schaub Houston Texans 92.8 29.0
Alex Smith San Francisco 49ers 95.1 29.8
Jay Cutler Chicago Bears 83.1 30.0

Looking at the spread of this data, we can see that it shows what statisticians call a “normal distribution,” which is a fancy way of saying that the frequency of the numbers peaks around the mean (average) and tapers off toward either end of the range. In this case, the range is roughly 20 to 30.

Lessons

A quick glance also tells us that more consistent does not necessarily equal to better: five of the six least consistent quarterbacks rank in the top ten for passer rating over the last two years. Indeed, there is almost no correlation between a quarterback’s average passer rating and his standard deviation(r2=0.002). In other words, there is no indication that consistency is necessarily a marker of excellence, for a quarterback can just as easily be consistently bad as consistently good.

Sam Bradford is living proof that being consistent doesn't mean you're good.

St. Louis Rams quarterback Sam Bradford is living proof that being consistent doesn’t mean you’re good.

This makes intuitive sense. St. Louis Rams quarterback Sam Bradford has put up the most consistent passer rating in the NFL the last two years — but no one would accuse him of being an excellent quarterback. There is no value found in being consistently mediocre.

The next two most consistent quarterbacks, however, have been two of the best in recent years. Ask the average NFL fan to name the best two quarterbacks of 2011 and 2012, and the most common answers would likely be Aaron Rodgers and Tom Brady (Drew Brees would be in the mix as well), and indeed, they rank as two of the top three in passer rating. Interestingly, though, seven of the top ten highest-rated quarterbacks rank in the bottom half for consistency.

This suggests that, among the top quarterbacks, what separates the truly elite players from the rest is their ability to avoid bad games and be consistently excellent. The numbers suggest that may be possible, as the correlation between passer rating and standard deviation rises to 0.38 if the sample size is limited to the top ten highest passer ratings It should be noted, however, that 0.38 still represents a relatively low correlation.

Now I want to look briefly at one interesting case for a quarterback who did not qualify for this study because he missed the 2011 season: Peyton Manning. I am looking at quarterbacks playing for the same team, so rather than combine his 2010 and 2012 numbers (which featured him plying his trade in two different cities), I decided to look at his numbers from 2009 and 2010. In those years, Manning posted a passer rating of 95.6 with a standard deviation of 22.2. His passer rating would rank only sixth in this study — likely because he missed out on the passing bonanza that was 2011, when defenses suffered tremendously from the lockout and shortened training camp — while his standard deviation would score him as the fifth most consistent quarterback.

These numbers actually muddy the waters a little bit: Manning falls short of the elite benchmark in passer rating but is still relatively consistent (similar to Ben Roethlisberger).

Tom Brady is among the best and most consistent quarterbacks in the NFL.

New England Patriots quarterback Tom Brady is among the best and most consistent quarterbacks in the NFL.

Conclusion

Those of you who don’t like wading through a whole long article full of numbers — in other words, all of you — can skip straight to this point and read what I learned in easy-to-digest bullet points!

  • There is no statistical relationship between consistency and effectiveness for NFL quarterbacks.
  • It looks possible, but is not proven, that the truly elite quarterbacks are separated from the merely good ones by being consistently good.
  • Second-tier quarterbacks are some of the most inconsistent in the NFL, probably because they fluctuate so often between good and mediocre.

Stay tuned for an upcoming look at the NFC North quarterbacks!

About the author

Jon Vander Woude enjoys writing in-depth analytical articles that examine statistical trends in the NFL offseason. He also covers the Chicago Bears beat for Water Cooler Sports. Despite growing up in Michigan, California, and Miami, he had the good fortune to be reared by a father who grew up in Chicago raised him to root for the Bears, Bulls, and Cubs. Feel free to write him at with any questions, comments, or suggestions for future columns. Connect with

577 comments
jwoude23 Bear Down
jwoude23 Bear Down moderator like.author.displayName like.author.displayName 2 Like

natradamus
natradamus moderator like.author.displayName 1 Like

there should be another sliver in April for football in honor of the draft-  the off season optimism of fanbases- and the sudden loss of memory for the talent of your favorite team

Green And Gold
Green And Gold moderator like.author.displayName like.author.displayName like.author.displayName 3 Like

natradamus
natradamus moderator like.author.displayName 1 Like

those are some fugly kids

natradamus
natradamus moderator

her surgeon needs a copy of this pic

natradamus
natradamus moderator

   exactly.   "you wanna see my work,  Mendhal has nothing on my abilities"

___bp___
___bp___ like.author.displayName 1 Like

  Right, for marketing purposes.

Green And Gold
Green And Gold moderator

Sad:

Donald Driver appears to be leaning strongly toward retiring this offseason, according to a report in USA Today.

The report, which cites a source who's familiar with Driver's thinking, said Driver isn't 100 percent sure but could announce his retirement as early as next week.

Driver, who turns 38 next week, has played his entire 14-year career with the Packers. He caught only eight passes this season was inactive for three of the team's last five games this season, playoffs included. He was a healthy scratch in two of those three games.

___bp___
___bp___

 It is sad, but he didn't seem to have it anymore.  NOt that he couldn't still get open and catch a ball or two, but the ability to separate was diminished, and I saw him fail to get to balls that a pro WR should get to.


He's been a good Packer.  I wish he had not been injured in teh SB so he could feel a little more complete about that ring.

Green And Gold
Green And Gold moderator

 We are gonna miss him...

natradamus
natradamus moderator

  I like Driver- the guy seemed to be classy both on and off the field.  You should have know when he went on DWTS that it was over.  this year was just a farewell tour for the guy, but he got paid.

___bp___
___bp___ like.author.displayName 1 Like

  Already do.  I mean, miss the guy he used to be.  

Preparation_A
Preparation_A like.author.displayName like.author.displayName like.author.displayName like.author.displayName like.author.displayName 5 Like

OK, I am gonna brave the anserine horde attempting to lay siege to my office.

Have fun storming the castle.

Preparation_A
Preparation_A

JESUS SHIT THAT'S A LOT OF GEESE

Um...
Um... moderator like.author.displayName 1 Like

 I had about 300 of them flying over me the other day while I was walking. I was convinced one would shit on me.

Maized and Confused
Maized and Confused like.author.displayName 1 Like

 GOOSEPACOLYPSE!!!

Preparation_A
Preparation_A

   

Seriously. I want to leave but these fucks have taken over the parking lot. Probably close to 500 of them..

Preparation_A
Preparation_A

   

No!

A: It's winter and they have none right now.

B: Geese with children are the LAST thing I'm going to attack...those fuckers mean business!

Maized and Confused
Maized and Confused like.author.displayName like.author.displayName 2 Like

  

Find one with children and attack it.

That oughtta help you out.

___bp___
___bp___ like.author.displayName like.author.displayName like.author.displayName like.author.displayName 4 Like

andylet445
andylet445

I want her name and how i can find her.

Green And Gold
Green And Gold moderator

  Looks like she is from Spain

___bp___
___bp___

   Think?  Her blond looks too natural for me.

Preparation_A
Preparation_A

  

DAAAAAAAAAAAAAAAAAAMMMMM

___bp___
___bp___ like.author.displayName 1 Like

  Yeah, one of the hotter women I have seen for a while.

jwoude23 Bear Down
jwoude23 Bear Down moderator like.author.displayName like.author.displayName like.author.displayName 3 Like

Maized and Confused
Maized and Confused like.author.displayName 1 Like

 Lol, as an analyst whose boss asks for just about everything in log scale for no reason, I approve of this.

Preparation_A
Preparation_A

  

And for cockheads that can't accept curvilinear relationships.

andylet445
andylet445 like.author.displayName 1 Like

FUCK!! How did i not see this?


Um...
Um... moderator

 Who's the chick on the left?