What is the Correlation Between Offensive Line Play and QB Play?

Look at the trajectory of Baker Mayfield’s career: a strong rookie season had people thinking he was the next big thing in the NFL, then a sophomore slump in 2019 had people calling him “overrated as hell” and wondering if he might even be a bust. He bounced back in a major way in 2020, finishing the season with a QBR of 72.2, which put him in the top 10 and just 0.3 points behind Tom Brady’s 72.5.

The trajectory of Mayfield’s career over his first three seasons tracks pretty well with the performance of the Browns season offensive line ranks (according to Pro Football Focus):

  • 2018: #2 ranked offensive line in the NFL
  • 2019: #23 ranked offensive line in the NFL
  • 2020: #1 ranked offensive line in the NFL

His “sophomore slump” year was also the year where he had to deal with the worst offensive line play of his career. I don’t think that’s a coincidence.

NFL quarterbacks are heavily dependent on the strength of their offensive lines. It’s undeniable. Look at how ineffective Patrick Mahomes was in the Super Bowl: he didn’t look anything like his normal self, and a big part of that was because his offensive line was decimated by injury. His starting tackles were both out, plus starting guard Laurent Duvernay-Tardiff opted out before the 2020 season.

If even Patrick Mahomes is ineffective when forced to deal with bad offensive line play, then it should be obvious that quarterbacks are, to a large extent, only as good as their offensive lines.

So what I wanted to do was compare teams’ QB play with their offensive line grades. This will be done via scatter plot. On the Y-axis, we’ll have teams ranked by “Pass Block Win Rate” as calculated by ESPN, and on the X-axis, we’ll have the teams’ ranks in overall passer rating for the 2020 season. I was going to use Pro Football Network’s individual QB ranks, but due to injuries it didn’t include every QB that played in the league this season. So I thought using each team’s overall passer rating, which includes every QB that dropped back and threw passes behind that team’s offensive line, would be more representative of how effective a team’s passing game was.

Additionally, I was going to use the PFF offensive line ranks, but those also include run blocking grades. Even though QBs benefit from their teams having great running games, I wanted to focus exclusively on pass blocking ranks here because this is about passing.

Because these are based on 1-32 rankings, the lower you are the better. The Packers had the #1 offensive line in terms of pass block win rate, and Rodgers also posted the #1 passer rating in the league this season.

Further to the left = better QB play, further to the bottom = better O-line play.

So if you’re in the bottom left, it means you got good QB play and good offensive line play. If you’re in the bottom right, it means you got good offensive line play and bad QB play. As we can see, there are a few teams (Rams, Bears, Patriots, Washington, Philly) that had decent or even great offensive line play but bad QB play.

Towards the top left, we have teams that had good QB play but bad offensive line play. The Chargers stand out big-time: Justin Herbert was excellent despite having a bottom-3 offensive line in the league, which really makes his rookie season that much more impressive: not only did he rewrite the rookie QB record books, he did so behind a trash-tier offensive line. DeShaun Watson, Ryan Tannehill, Kirk Cousins and Tom Brady overperformed in terms of the quality of protection they were given.

In the top right, we have teams that had bad QB play and bad offensive line play. Now, with the Bengals, obviously we know Joe Burrow only played in 9 of their 16 games, so they’d be higher on the passer rating scale had he been able to play all 16 games. But clearly the Bengals need to upgrade their offensive line, and this is why I think, as tempting as it may be to draft Jamarr Chase at #5 and pair him up with Joe Burrow again, they really should draft Penei Sewell and give Burrow some protection. It’s not a sexy pick, but if they don’t improve that offensive line, Joe Burrow is not going to last long in this league.

Overall, we see a decent correlation between offensive line play and QB play. Quarterbacks that have good offensive lines generally do pretty well. There are some exceptions, notably the Rams, but they have already upgraded at QB with the Matt Stafford trade. If the Rams’ offensive line can maintain its strong play in 2021, I expect the Rams to be legit Super Bowl contenders.

Takeaways:

  • Drew Lock was terrible last season. His protection wasn’t great–21st ranked–but he underperformed his offensive line. The Broncos ranked dead last in the league in passer rating with Lock starting 13 games. And the thing is, Denver has some pretty good offensive weapons. Melvin Gordon and Philip Lindsay running the ball, plus Jerry Jeudy, KJ Hamler, Courtland Sutton (injured early on) and Noah Fant catching the ball–that’s a good bunch of skill players. I think Denver could move off of Lock if Justin Fields is available at #9, which seems increasingly likely.
  • Cam Newton severely underperformed his offensive line, which ranked 13th in pass blocking. Cam was the 27th-ranked passer in the league. However, unlike Drew Lock, Cam did not have quality weapons last season. As I wrote in a prior post, the Patriots either had the worst or second-worst skill position players in the NFL last season–it’s between them and the Jets. So while it’s concerning that Cam severely underperformed his offensive line, I think he deserves some benefit of the doubt because his weapons were so bad.
  • For all the talk about how Russell Wilson needs more protection, his offensive line was 9th in pass blocking. I keep saying this: a lot of the sacks Russ takes are his fault. He tends to hold on to the ball too long. This is why I call him the king of getting sacked after 5+ seconds.
  • The Dolphins QBs overperformed their offensive line, which ranked 27th in pass blocking. Does this mean Tua is actually pretty good and doesn’t deserve all the criticism? Maybe, but keep in mind that Ryan Fitzpatrick played a lot of games for Miami last year, too. Tua played 9, Fitz played 7. The Dolphins had an overall passer rating of 91.2 for the season, but Tua actually dragged that down, posting an 87.1 passer rating compared to Fitzpatrick’s 95.6.
  • I’m not really convinced that the Jets should move off of Sam Darnold. As I said above, the Jets either have the worst or second-worst offensive skill players in the league. On top of this, their offensive line ranked 29th in pass blocking. That is not a recipe for success. If the Jets think Sam Darnold is the problem, and that everything will be fine once they swap him out for Zach Wilson, they’re wrong. He might suck; it’s entirely possible he is the problem. But unless they upgrade their skill players and their offensive line, Zach Wilson is probably going to suck as well. The Jets did sign Corey Davis and Keelan Cole to upgrade their WR corps, which is encouraging, but there’s still a long way to go. They signed TE Tyler Kroft, the former Bill, but he’s not the answer at TE; he’s been in the league for 6 years and only has 85 career receptions. They only added one offensive lineman in free agency, Dan Feeney, and he’s coming over from the Chargers, who were one of the few offensive lines worse than the Jets’ last season. I get why the Jets might want to start fresh at QB with Wilson, but if they expect him to fix all their problems, they’re going to be disappointed.

I keep seeing all these mock drafts where people have the first 10 picks as nothing but QBs and skill players. I get it: guys like Kyle Pitts and Jamarr Chase are incredible prospects, and it’s fun to imagine them being plugged in with these teams that are drafting in the top 10. But there should be at least 2 offensive linemen drafted in the top 10 this year.

Todd McShay’s latest mock draft has Sewell falling all the way to 13 to the Chargers! This is ridiculous; I don’t think he should slip past the 5 spot. I think there’s a strong case to be made for the Jets taking him at 2, even though it’s probably not going to happen. If the Bengals pass on him at 5, Joe Burrow should just demand a trade right on the spot, because at that point he’ll have to genuinely wonder if the Bengals are trying to get him killed. Even Atlanta would benefit from taking Sewell at the 4 spot.

Overall, building up your offensive line is critical to success in the NFL. Look at the teams where the QBs under-performed the offensive line: Washington, New England, Chicago, Philly and the Rams. Only Philly was a bad team. The Eagles are the only real outlier here in terms of being a team that had good a offensive line and still sucked. If you have a good offensive line, you’re probably going to be a good team.

Before we conclude, I’ll leave this final stat. It’s the top 14 teams in terms of pass block ratings, and I’ll put in bold the teams that made the playoffs in 2020. It’s a big overlap:

  1. Packers
  2. Browns
  3. Cardinals
  4. Bills
  5. Saints
  6. Chiefs
  7. Rams
  8. Ravens
  9. Seahawks
  10. Raiders
  11. Eagles
  12. Colts
  13. Patriots
  14. Washington

Of the top 14 offensive lines in the NFL in terms of pass block win rate, 10 of them were playoff teams. The formula for success in the NFL starts with the offensive line.

Austin Frank

Sports blogger

3 thoughts on “What is the Correlation Between Offensive Line Play and QB Play?

  1. Tom Brady went to Tampa Bay, knowing they had a great defense and good offensive line. But they had a losing season the previous year. What made it all come together, in my opinion, is Tom Brady’s overwhelming desire to win, win big, and bring the whole team along by his example. He believes. Aaron Rogers, probably the best quarterback in the NFL, is amazing, but I don’t think he believes, or doesn’t know how to enervate those around him as such. What makes team go above what’s on paper is the belief the players have, then their unending determination to get there.

    Liked by 2 people

    1. I totally agree. When Brady joined that team, those players all realized “we can win.” If he believes, they’re going to believe. There’s a reason every player in the league wants to play with Brady.

      Liked by 1 person

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