NFL Quarterback Research: 1978-2013, Nick Foles in Proper Context

Rob Pitzer

foles

Editor’s Note: On occasion we highlight an article or two that would normally be featured on our Premium Content page. This is the second part in a series of articles from Rob Pitzer who put in a tremendous amount of research on quarterback production. We’ve also unlocked the first installment in the series for all to enjoy. If you’re one of the few remaining who have yet to sign up for our Premium Content package, just click here.

This off-season I started wondering what I might be able to learn about Nick Foles’ future career prospects by looking at historical quarterback seasons.  The first step of that project is described here and yielded some pretty interesting information about how defense-adjusted net completion, touchdown, interception and sack percentages could be used to determine just how valuable a quarterback’s season was to his team.  I don’t want to get hung up repeating everything, so what follows below assumes familiarity with that article.

As mentioned already, the inspiration for looking at quarterback data was Foles’ 2013 season, but more specifically I wanted to see find out how his year looked if you dissected it.  Going into the analysis I knew four things:
  1. His TD rate was off the charts high
  2. His INT rate was off the charts low
  3. He took a lot of sacks
  4. The defensive SOS he threw against was extremely weak
Did that particular combination of components suggest anything about his future?
It turns out it does and I got a better answer than I could have hoped for in terms of clarity — though not necessarily the one I’d have liked to find as an owner of Nick Foles in ten leagues. It’s a mixed bag.
First, let’s recognize Foles’ season was, in fact, historic.  Even after adjusting for his defensive SOS, the Eagles’ passing game was responsible for +4.33 wins in 2013.  In the 938 seasons I have data for, that ranks as the 15th best total since 1978.
Making it even more extraordinary is only one quarterback in the last 35 years put up similar numbers under the age of 27 — Dan Marino, with +4.41 wins in 1983 (age 22) and +5.51 wins in 1984 (age 23).

Interestingly, Foles’ performance came against what appears to be the weakest collection of defenses any quarterback has had the good fortune of facing in NFL history.  Though the data only goes back to 1978, it’s virtually impossible (and ‘virtually’ here is a just weasel word to cover all bases) that any defensive SOS prior to 1978 was weaker given the rule changes since that time.

His weak schedule is accounted for in my wins estimate by the fact we’re using net numbers (i.e. actual performance vs expected performance given the defenses faced), but to the degree that the relationship between defenses faced and quarterback performance isn’t linear at the extremes, my take on Foles’ season might be somewhat too favorable.

More importantly and more interestingly, I looked at whether some of the individual components of a quarterback’s season might matter more than others looking forward.  Specifically I wanted to see how Net Completion Rate and Net Sack Rate compared to Net TD Rate and Net INT Rate in terms of predictive power.

A quick glance at the four data points that make up Foles’ 2013 will explain why:

  1. Net Comp Rate, + .86%
  2. Net TD Rate, + 3.36%
  3. Net INT Rate, +2.04%
  4. Net Sack Rate, (-2.08%)

Again, those net numbers are just Foles’ actual rates less what you’d expect an average quarterback to do vs the exact same set of defenses.

Given the volatility of TDs and INTs and the research I’ve done on quarterback prospects that suggests collegiate sack rates are very important, I was expecting there might be a difference in the predictive value of those components, but had no idea of the scale and wouldn’t have been shocked if my hypothesis had been wrong.

It was not wrong.

What follows is the list of quarterbacks under 26 years old with an estimated Win Total of +2.0 or greater (per the formula in the earlier article).  There are 243 total seasons in my data set where the quarterback was under 26, and 30 of those met the +2.0 total cutoff.

In order to highlight the lede, I’ve ordered those thirty qualifying seasons on the basis of Net Completion % + Net Sack % (ignoring TD % and INT %), and cut out the middle half of the data for clarity:

Carson Palmer, 2005, +11.2%
Joe Montana, 1980, +11.0%
Dan Marino, 1987, +10.9%
Bernie Kosar, 1987, +9.9%
Peyton Manning, 1999, +9.5%
Troy Aikman, 1992, +9.3%
Dan Marino, 1985, +8.7%
Dan Marino, 1986,  +8.3%

[snip]

Ken O’Brien, 1985, +3.0%
Scott Mitchell, 1993, +2.0%
Ben Roethlisberger, 2005, +0.7%
Dave Krieg, 1984, +0.6
Dave Krieg, 1983, +0.5%
Neil Lomax, 1983, +0.1%
Ben Roethlisberger, 2007,  -0.2%
Nick Foles, 2013, -1.2%

Again, these are the top eight and bottom eight totals (Net Comp % + Net Sack%), with the middle fourteen cut out.  As you might expect what you find in-between those two groups are some players who, with the benefit of hindsight, belong in the bottom group and some who’d be better placed in the top set.

The top group is comprised of four Hall of Famers, a quarterback who had his career wrecked by injuries and a disastrous organization immediately after posting his best year (Palmer) and another who never came close to matching the season here (Kosar).

The bottom group is made up of solid-to-good NFL quarterbacks — and more about them in a minute.

If that seems anecdotal, what we see above is repeated for quarterbacks older than 26 as well.  Below are ALL of the quarterback seasons where the sum of the net completion and net sack rates are greater than 8.0%.

Dan Marino, 1984, 14.2%
Joe Montana, 1987, 13.0%
Drew Brees, 2009, 12.5%
Drew Brees, 2011, 12.3%
Joe Montana, 1989, 12.0%
Joe Montana, 1981, 11.8%
Warren Moon, 1992, 11.7%
Peyton Manning, 2003, 11.6%
Steve Young, 1997, 11.5%
Tom Brady, 2007, 11.5%
Troy Aikman, 1993, 11.3%
Carson Palmer, 2005, 11.2%
Peyton Manning, 2009, 11.1%
Joe Montana, 1980, 11.0%
Dan Marino, 1987, 10.9%
Steve DeBerg, 1979, 10.8%
Peyton Manning, 2005, 10.6%
Dan Marino, 1988, 10.4%
Steve Young199310.4%
Kurt Warner, 2001, 10.4%
Steve Young, 1991, 10.2%
Peyton Manning, 2004, 10.2%
Troy Aikman, 1995, 10.1%
Bernie Kosar, 1987, 9.9%
Peyton Manning, 2013, 9.9%
Peyton Manning, 2002, 9.8%
Steve Young, 1994, 9.8%
Chad Pennington, 2002, 9.6%
Tom Brady, 2009, 9.6%
Joe Montana, 1983, 9.6%
Peyton Manning, 1999, 9.5%
Troy Aikman, 1994, 9.5%
Kurt Warner, 2008, 9.4%
Chad Pennington, 2004, 9.4%
Peyton Manning, 2012, 9.4%
Troy Aikman, 1992, 9.3%
Joe Montana, 1986, 9.2%
Joe Montana1985 9.2%
Drew Brees, 2007, 9.2%
Joe Montana, 1984, 9.1%
Steve Young, 1992, 9.1%
Drew Brees, 2013, 9.0%
Brian Griese, 2004, 8.9%
Philip Rivers, 2013, 8.9%
Troy Aikman, 1996, 8.9%
Steve Young, 1995, 8.8%
Kurt Warner, 2000, 8.7%
Carson Palmer, 2007, 8.7%
Dan Marino, 1985, 8.7%
Drew Brees, 2010, 8.7%
Peyton Manning, 2008, 8.6%
Peyton Manning, 2006, 8.6%
Brett Favre, 2007, 8.5%
Tim Couch, 2000, 8.4%
Matt Ryan, 2013, 8.4%
Matt Schaub, 2009, 8.3%
Dan Marino, 1986, 8.3%
Steve Young, 1996, 8.3%
Tony Romo, 2010, 8.2%
Dan Marino, 1995, 8.2%
Drew Brees, 2006, 8.1%
Peyton Manning, 2010, 8.1%

There have been some EUREKA! moments like this one in my NFL prospect research where something suddenly shows up in 10-story Times Square neon, but the central finding here is as big an AHA! as I’ve had:

While TD and INT rates ebb and flow, consistently completing more passes and taking fewer sacks than expected based on the defenses played is the hallmark of a great quarterback.  It’s what defines them.

In other words, touchdowns and interceptions are more useful for describing what already happened than they are for looking forward.  Conversely, completion rates and sack rates are less tied to seasonal success (you can look at the coefficients from the formula in the previous article to see the relative values), but have far more predictive power about a QB’s ultimate quality than do TDs and INTs.  

I have some thoughts on why that might be, but for now let’s get back to our original purpose… based on that finding, what can we say about Foles and his historic 2013 season?

For starters, the heavy reliance on high TDs and low INTs in his overall Win Total is not a recipe for sustained greatness.  In fact, it’s completely reasonable to suggest that Foles will not emerge into the next Manning, Brady or Brees.  Typically those types of talents show themselves at an early age via their defense-adjusted completion rates and sack rates — even if the TDs are slow to come, or the INTs are initially high.

However, the players who looked most like Nick Foles at a young age (good Win Totals based primarily on net TD and net INT rates) are still a strong and tightly clustered (in terms of career success) set of quarterbacks.

They’re listed here along with the top-20 fantasy football finishes for each (per PFR):

Dave Krieg:  3, 5, 10, 10, 10, 12, 17, 18, 19, 20
Neil Lomax:  2, 4, 6, 8, 10, 17, 19
Ken O’Brien:  2, 6, 10, 12, 16, 17, 20
Scott Mitchell:  2, 9, 11
Ben Roethlisberger:  4, 9, 12, 13, 14, 17, 18, 19, 19, 20 (better on a ppg basis)

So, looking only at his comparables, we should expect Foles to have at least a few more top-10 finishes and several more in the top-20.  However, I believe that projection may prove conservative for two reasons.

First, Foles may be in an extremely friendly system.  It’s possible that Foles/Kelly could end up being a long-term show and while the higher than average touchdowns will regress, they may not fade entirely if Kelly’s system stands the test of time.

Second, and possibly related to the friendly system, is that Foles’ 2013 season — with its +4.33 win total — was actually better than the seasons put up by his comparables at a similar age.  The incredible TD and INT rates were definitely a fluke, but it could be that they aren’t entirely flukey. 

Based on all of this, I decided that Foles is a hold for me right now.  If there were a young, elite, undervalued quarterback out there you could flip him for, it might make sense to do it, but absent that it may be best to ride the QB1 finishes while they’re available and try to make him part of a strong QBBC committee if it turns out that last season was the high water mark.