NFL Passer Ratings and Completion Percentages: What Do They Really Mean?

At some point in the 2000's, it must have been decided that passer rating and completion percentage are the end all be all statistics in football.  Particularly passer rating.  It's even the default category on several prominent sites including ESPN with regards to quarterback statistics.

Many people call it QUARTERBACK RATING so often to the point where one actually forgets that it's actually called passer rating.  Where one forgets that this is just an arbitrary formula made up 30 or so years ago and was only given so much emphasis 10 or so years ago.

Now, I would not have that much of a gripe if one at all about this formula if it served as an all-encompassing formula such as player efficiency rating serves in basketball.     When you look at the all-time list of player efficiency rating in NBA history virtually everyone near the top of the list is one of the greatest to play the game. Nothing but HOFers.

Passer rating?  Well let's just say this is what I've learned according to passer rating if it's the No. 1 way to evaluate quarterbacks.

Things I Learned From Passer Rating

Lesson No. 1
a)Aaron Rodgers is the Greatest Of All-Time
b)Tony Romo is a top four QB in NFL history
c)Both of these QBs are greater than Manning, Warner, and Brady

Lesson No. 2
a)Chad Pennington is an all-time great
b)So is Daunte Culpepper
c)So is Carson Palmer
d)So is Jeff Garcia
e)So is Matt Schaub
f) All these QBs are greater than Favre and McNabb

Lesson No. 3

a)David Garrard is better than Rich Gannon
b)Marc Bulger had a career on par with Jim Kelly
c)Jay Cutler was better than Steve McNair (RIP)

Lesson No. 4

a)Jason Campbell was better than Jake Delhomme and on par with Brad Johnson
b) Brian Griese better than all of those guys
c) All the guys listed in a & b over Randall Cunningham
d) All those guys listed in a & b over Warren Moon
e) They are better than Troy Aikman as well

Oh and let's not forget

Byron Leftwich over Eli Manning's sub 80 passer rating.  Speaking of sub 80 passer rating that brings us to our final lesson.

Final Lesson
Basically according to passer rating, Vick's career was on the same level
of Tim Couch and David Carr.

And in fact since both guys had decisively better career completion percentages (59.8 completion percentage for Carr & Couch to Vick's 53.7 completion percentage) then the final lesson we learn from passer rating and completion percentage is:

David Carr and Tim Couch both had better careers than Michael Vick.

Or at the very least just as good of careers on the football field.

And notice these comparisons don't include players who played primarily in the 1970's or 1960's to make a point.   Jim Kelly is the one guy who played a lot in the 1980's who I perhaps could have left out but the point still remains.   It doesn't even come close to successfully evaluating players who have played in the same era, let alone different eras.

What Should We Really Learn?

IN Reality

Passer rating should not be a formula that people take nearly as seriously as they do.    It's a random, intangible formula arbitrarily made up, recently given so much meaning. And to be quite frank analysis in terms of how it ranks players shows that it is almost meaningless. Yet we are convinced that it's the most meaningful arbitrary formula ever created. 

It's quoted on television far more than a much more credible and all encompassing formula such as player efficiency rating. In fact when was the last time you ever heard such a formula quoted on Sportscenter?  They sort players numbers by tangible stats that they have been using since day one. Not some made up formula with a well below 50 percent and barely 33 percent of HOFers on the all-time list.

Original Design

Even more telling is the individuals who were responsible for the invention of this formula in 1973 even advised people that it wasn't the end all be all of statistics.

It was a formula which took completion percentage, passing yardage, touchdowns, and interceptions as a way of measuring a QB against a specific standard.  Never intended to rank QBs against other specific QBs.

In an article in the NY times back in 2004, it was admitted that it didn't account for intangibles qualities such as ability to perform in the clutch or leadership.  It also didn't even account for tangible qualities such as rushing.  ''This is a forward-passing statistic. Rushing has nothing to do with it,'' were the words of Don Smith the PR man behind the Pro Football HOF who was influential in bringing this formula to life.

Yet since then this formula has taken a life of its own.  It's even listed as QUARTERBACK rating on the NFL.com website. Which subconsciously or consciously can convince someone that this is an all-concompassing formula.

There are no such disclaimers of the founders of this formula that you find anywhere.  They have become highly accepted particularly over the last five or six years where they have become even more prevalent statistics during television broadcast of games as well as graphics shown during shows with highlights.

Fatal Flaw- Completion Percentage

In addition to being now coined a QUARTERBACK rating without evaluating all the ways a quarterback can affect the game even from a tangible standpoint, let alone intangible, the biggest flaw perhaps of the passer rating system is how heavily it is attached to Completion Percentage.  

Which is kind of amusing when someone points to a quarterback who doesn't have a great passer rating and cites completion percentage as corroborative evidence of the lack of effectiveness of that particular QB, when those two statistics could not be any more correlated.

There is a reason why a guy like Chad Pennington who ranks so high on the all-time list of completion percentage is also high on the list of passer rating. It's many of the same names at the top of both lists.  Same for a Daunte Culpepper. Completion percentage is a misleading statistic that does not take into account routine spectacular catches/routine drops, dump off passes/throw aways, or first down scrambles. It also can be heavily skewed when the total number of pass attempts per game is not high.   One to two incomplete passes a game could make all the difference between what's considered respectable and poor.

For Instance:

Let's take a QB who only averages 24 pass attempts per game.

And let's say they complete 13 out of those 24 passes a game.

In today's game that would be an abysmal 54% completion percentage.

Now what if they were to complete just 1 more pass per game?

Let's say they traded a shot down the field for a dump off pass,
or let's say that one pass a game was a difference between, a spectacular
catch or a drop.   Or what if it was the difference between a smart throw away and a sack?

Let's just even say it was a bad pass.    Does 1 extra bad pass a game
really that disparaging to someone's overall performance, especially
when they can more than make up for that bad pass with their overall TD/yardage production?

Would you rather have that one extra pass completed a game with someone who is dinking and dunking and not producing points, not moving the chains, and/or even worse someone who has more turnovers than TDs?

Even if it was 2 extra bad passes a game, once per half, is that really that disparaging either?

Is that QB who throws those one to two extra head scratchers a game an indictment on that QB's overall performance?

Especially when they are producing touchdowns, yards, and wins at an above average clip out of all those offensive snaps. 

Is that enough to justify saying they belong in the same categories as players who rank well below average in all those other categories such as touchdowns, touchdown/turnover ratio, yardage, and wins?

That player who elevates their team put in the same category as the players who are colossal busts or that their teams win in spite of them in every facet.

Does that seem logical?   Certainly shoudln't when you truly break it down.

But these comparisons are always made.

Completion Percentage In Passer Rating Formula

Completion percentage plays perhaps the biggest factor in the entire passer rating formula to the point where someone who has a not so great touchdown to interception ratio can rank near the all-time greats while someone such as McNabb who has the second best TD/INT ratio of all-time is not even in the top 15 in that category that only uses those four statistics.   This is again why on the all-time passer rating list has those names that clearly don't belong above current/future HOFers.

The Michael Vick (Passer Rating) Experience

If that is not telling enough perhaps this is the most telling stat of how skewed it is in terms of completion percentage.

Michael Vick's career passer rating is 75.9.

Using the passer rating formula, a Quarterback who completes 74 percent of their passes is rewarded so much that if that quarterback threw for a net total of ZERO passing yards, they would have a better passer rating than Vick.

In fact even if their passing net total was in the negative.  It could be -50, -500, -5000, -500,000,000,000.   It doesn't matter as long as they don't throw a pick and maintain a certain completion percentage.

Forget the fact that passer rating tells us even David Carr and Tim Couch were as good as Vick.

According to the passer rating formula, a QB with negative infinity passing yards with a great completion percentage is a better player than Vick ever was.

Because if they complete 74 percent of their passes they would have a passer rating of 76.2

Need we say anymore about either one of those two formulas?

Or do we continue to go on under the assertion that these "lessons" we learned from this formula in terms of player rankings actually have validity?