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Columns - Magazine

Valuing QB Pass Protection

by Jonathan Bales
Updated On: October 4, 2018, 4:09 pm ET

I’m part of what I’d imagine is a small group of people who believes that a team’s offensive line isn’t as important as we’re led to believe. Don’t get me wrong—the offensive line certainly matters, particularly for run blocking—but I don’t think there’s as much upside in building an elite offensive line (at least as far as passing the ball efficiently goes) as there is in finding a difference-making wide receiver, for example.


If I were building an NFL offense, I’d make sure that the offensive linemen reach a certain baseline talent level in pass protection and can win in short-yardage situations, totally punt the running back position, then equip my quarterback with all-star-caliber pass-catchers.


To give you an idea why this is the case, consider that the best pass-blocking team in the NFL this year—the Denver Broncos—has a Pass Blocking Efficiency rating (via Pro Football Focus) of 86.9, meaning they’ve adequately protected Manning on 86.9 percent of his dropbacks. The median NFL offense is at 79.1 percent. So we’re talking about seven or eight percentage points between the best offensive line and a totally average one.


Now consider the impact that a player like A.J. Green, Dez Bryant, Rob Gronkowski, or Josh Gordon can have on an offense. Their ability over a replacement-level pass-catcher is monumental, whereas it is extremely difficult to build an entire offensive line that is that much more dominant than an average one across the board. More players, more chances for injury, less of an impact on a per-player basis.


Again, I want to stress that I don’t think the offensive line is irrelevant, but just that 1) their impact is greater in the running game and 2) it’s most important to make sure there aren’t any weak links than creating a unit of elite players. In short, I’d rather have first-round receivers and a group of second and third-round linemen than the other way around.


Pass Protection and Passing Efficiency


I have some more thoughts on this idea, but first I want to dive into some numbers. I imported some pass protection stats from Pro Football Focus (sacks, hurries, total pressure and Pass Blocking Efficiency) to compare with overall passing stats. Below, I charted the strength of the correlation between these variables.




The strongest correlation here is between sacks per dropback and Net YPA, which isn’t really all that surprising since sacks are already a component of Net YPA. Otherwise, there’s certainly a correlation between pass protection and passing success; offenses that allow fewer sacks and hurries ultimately pass the ball with greater efficiency and accumulate more fantasy points through the air.


However, none of these correlations are particularly strong. It seems like sacks allowed and PBE are the best predictors of passing success (especially PBE when you consider that Net YPA and total passing yards don’t account for the metric like they do for sacks).


Here’s why I think pass protection might be a little bit overrated when it comes to predicting overall pass success…


Quarterbacks Mostly Protect Themselves








That’s a list of the rank of Peyton Manning’s offensive lines in sack percentage (sacks allowed per dropback) in the last five seasons that Manning has played. His teams have been first every single season, and it isn’t close.


In the 2011 season in which Manning didn’t play, the Colts dropped from 1st to 14th in sack percentage, while the Broncos—the year before Manning got to Denver—ranked 26th!


Manning must be the most unbelievably lucky quarterback in NFL history, huh? That, or else he is responsible for making his offensive line look like All-Pros wherever he goes. Manning gets the ball out so quickly that he doesn’t even really need a better-than-average line to excel; he protects himself.


Across the league, many of the top quarterbacks do this same thing. Tom Brady and Drew Brees are two other highly immobile quarterbacks who get the ball out quickly and make their offensive line look good. As long as they don’t face immediate pressure, their production isn’t all that tied to the quality of their offensive line.


The relatively weak correlations between pass protection and passing efficiency and the fact that someone like Manning can immediately “transform” how we perceive an entire offensive line suggests that perhaps pass protection isn’t as important as we’re led to believe. Quarterbacks need a certain baseline of time to throw, but after that, they’re helped most by having elite pass-catchers who can get open and make plays.


When assessing rookie quarterbacks, those who switch teams, or even quarterbacks who have seen an injury to a key offensive linemen, our concern should be less about who is protecting them and more about making sure 1) there aren’t any very obvious weak links up front and 2) they have play-makers running downfield.