Just above these words, it says “posted by Chase.” And it was literally posted by Chase, but the words below the line belong to Adam Steele, a longtime reader and commenter known by the username “Red”. And I thank him for it. Adam lives in Superior, Colorado and enjoys digging beneath quarterback narratives to discover the truth; hey, who can blame him? One other house-keeping note: I normally provide guest posters with a chance to review my edits prior to posting. But due to time constraints (hey, projecting every quarterback in the NFL wasn’t going to write itself!), I wasn’t able to engage in the usual back and forth discussion with Adam that I’ve done with other guest posters. As a result, I’m apologizing in advance if Adam thinks my edits have changed the intent of his words. But in any event, sit back and get ready to read a very fun post on yards after the catch. When I envisioned guest submissions coming along, stuff like this is exactly what I had in mind.

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Introducing Marginal YAC

A quarterback throws a two yard dump off pass to his running back, who proceeds to juke a couple defenders and run 78 yards into the endzone. Naturally, the quarterback deserves credit for an 80 yard pass. Wait, what? Sounds illogical, but that’s the way the NFL has been keeping records since 1932, when it first began recording individual player yardage totals. The inclusion of YAC — yards after the catch — in a quarterback’s passing yards total can really distort efficiency stats, which in turn may distort the way he is perceived.

In response, I created a metric called Marginal YAC (mYAC), which measures how much YAC a quarterback has benefited from compared to an average passer. Its calculation is very straightforward:

mYAC = (YAC/completion – LgAvg YAC/completion) * Completions

I have quarterback YAC data going back to 1992 for every quarterback season with at least 100 pass attempts. ^[1]This data comes courtesy of sportingcharts.com. It’s obviously unofficial, but there doesn’t seem to be any noticeable biases from one team to another. Some unofficial stats, such as … Continue reading That gives us a healthy sample of 965 seasons to analyze, and includes the full careers of every contemporary quarterback. But first, let’s get a sense of what’s average here. The table below shows the league-wide YAC rates since 1992:

With the emphasis on the short passing game in recent years, it’s no surprise that YAC per completion has increased over the last decade. In 2013, yards after the catch represented an incredible 48.1% of gross passing yardage. It’ll be interesting to see if the trend continues and eventually pushes YAC above 50%.

So which quarterbacks have benefited the most and least from YAC? The table below shows the top 50 seasons of Marginal YAC since 1992. Daunte Culpepper, with 534 mYAC, is the single-season leader. In 2004, his targets gained 2,376 yards after the catch, producing 6.27 yards per completion after the catch. Since the average reception gained only 4.84 YAC in ’04, that means Culpepper’s Vikings gained 1.43 marginal YAC compared to league average. Multiply that by his 379 completions, and you get Culpepper’s mYAC number of 543.

The list is primarily comprised of great quarterbacks playing with great receivers, and bad quarterbacks who threw a bunch of checkdowns. The dichotomy between those two groups makes further analysis a bit murky. How should we divvy up credit for YAC between the quarterback, his receivers, and the system he plays in? I’ve isolated a few cases that may shed some light on the situation.

Here are the Packers during the Mike McCarthy era, with six seasons from Aaron Rodgers and two from Brett Favre:

Playing in McCarthy’s system, Green Bay quarterbacks have benefited from positive mYAC in seven out of eight seasons, with an average of 216 mYAC per year. That’s very high, especially considering that such a level was sustained for nearly a decade. Rodgers and Favre are both future Hall-of-Famers, so it’s fair to hypothesize that they have certain skills that allow their receivers to gain a lot of YAC. However, the Packers have been widely recognized as having one of the best receiving corps in the league during that span, and McCarthy has a reputation as a sharp offensive mind. Given all of that, do Rodgers and Favre deserve credit for their receivers’ YAC, or are they beneficiaries of a strong supporting cast and an advantageous system? What do you guys think?

Now let’s take a look at the Patriots during the Bill Belichick era:

This gets even more interesting. The Patriots have gained positive mYAC in 13 of 14 seasons under Belichick, including two seasons over 400. The Pats have been YAC monsters with a HoF quarterback, a mediocre quarterback, and a replacement level quarterback. They’ve done it with a revolving door of receiving targets, representing every conceivable type of pass catcher. They’ve done it with several offensive coordinators, applying conservative run-heavy schemes in the early years, and pass-wacky offenses in recent seasons. The only constant is Belichick. Does this mean Tom Brady is a product of his system? Would he be benefiting from so much YAC if he played for a different coach? The answer might be found in Matt Cassel and Drew Bledsoe:

Cassel with Belichick: +421 mYAC
Cassel without Belichick: -216 mYAC
Bledsoe with Belichick: +147 mYAC
Bledsoe without Belichick: -870 mYAC

The circumstantial evidence does not look good for Brady. Two passers who produce negative mYAC in other systems suddenly become YAC artists playing for The Hoodie. Furthermore, Brady has never been able to throw downfield consistently, so he seems like exactly the type of quarterback who would be dependent on Belichick’s YAC-heavy short passing system to cover his deficiencies.

One last table for the day – the 50 worst Marginal YAC seasons since 1992:

There are a lot of good quarterbacks on this list, including Peyton Manning (x4), Carson Palmer (x3), Mark Brunell (x5), Matt Ryan (x2), Steve McNair (x2), Drew Brees, and Troy Aikman. Why did these guys lose out on so much YAC? Surely their offensive systems were a major factor, emphasizing intermediate sideline routes rather than short passes over the middle. But that begs another question: Do these quarterback’s deserve extra credit for making harder throws that are less reliant on the receiver creating YAC? I’m still torn on what this all means for evaluating quarterbacks.

Before we get to Part II, though, I’d love to hear feedback from you guys.