Offensive line play has degraded across the NFL over the last decade

Free agency is just a couple of weeks away, and many fans of the Seattle Seahawks are wondering if the team will pursue any of the major free agent linemen set to be available. In 2017 the team went hard it its pursuit of free agent T.J. Lang, but came up short while also adding guards Luke Joeckel and Oday Aboushi. Aboushi and Joeckel combined to start nineteen games at the guard spots for the Seahawks, but they are both free agents once again this offseason and their performance on the field left a lot to be desired. Adding in the fact that both players dealt with injury issues that kept them off the field in 2017, it’s entirely possible neither of them returns to Seattle.

However, one thing to keep in mind as the team prepares to pursue free agents is the overall degradation of offensive line play across the NFL in recent seasons. As a result of a variety of factors, the performance of offensive lines across the NFL has been on a gradual decline over the last decade. Kevin Demoff, the Chief Operating Officer and Executive Vice President of Football Operations for the Los Angeles Rams touched on the decline of performance by younger players last week at the 2018 MIT Sloan Analytics Conference.

Because the video in that link is long (almost an hour), I’ll sum up the most pertinent point regarding young players that Demoff made, and that is that under the new CBA younger players are getting roughly two thirds less developmental practice time compared to under the old CBA. He stated this was a major contributor in the team’s failure to properly capitalize on the large number of draft picks acquired in the RG3 trade. After watching the video of Demoff’s statement, Field Gulls author Ben Baldwin tweeted that he wondered if it was possible to test for a slip in performance by younger players under the new CBA, and that would certainly be possible if one spent enough time to look at all the data. However, for something far more quick and dirty, it only takes a few minutes to get a handle on the slippage of offensive line play in recent seasons.

I am unaware of any metrics for run blocking that would show this decline, but in the passing game it is possible. The Pass Blocking Efficiency (PBE) metric ProFootballFocus.com publishes as one of its signature stats is an excellent way to demonstrate exactly what Ben was asking about.

Thus, in response to Ben’s question, I fired off the following tweet:

First thing to note is that my numbers were off. The 2006-2010 average was actually 2 teams per season with a PBE > 85, as I had missed the 2006 then San Diego, but now Los Angeles Chargers in my counting. It was just minutes after my tweet when PFF data scientist Eric Eager joined the conversation and shared an even better representation for the slide in performance by offensive lines.

That is a fantastic graphic representation of the slip in performance of offensive lines across the league, but it also shows that the slippage started long before the new CBA went into effect. Obviously, if it the decline existed before the current CBA, then there are other factors at play that go far beyond just the reduction in practice time. The most likely candidates would seem to be the propagation of the spread offense in the college game and the increase in athleticism among defensive linemen.

Thus, as free agency rapidly approaches and discussions turn towards the pursuit of free agent offensive linemen, keep the above chart in mind. In particular, while the Seahawks led the NFL with a PBE rating of 86.2 in 2007, that performance was only the the fifth best performance across the NFL in the 2006-2008 time period. In comparison, the identical 86.2 PBE posted by the 2014 Denver Broncos represents the highest single PBE attained by any team in the NFL in the five year period covering the 2013-2017 seasons.

Now, before I get accused of trying to make excuses for the Seahawks offensive line, that’s not what I’m doing. Just as with the article on the stuff rate, it’s important for expectations to be realistic. Does everyone wish to see Russell Wilson behind better pass protection? Absolutely, and with the Hawks returning four starters on the line, two of whom are set to be 23 and 24 next season, there is little reason to believe the line should not continue to improve.

However, it’s unlikely to improve as much as most fans want. Thus, it remains important to remember that improvement takes time. This is particularly true in today’s NFL, where practice time limitations are working against young players developing along the same developmental curves of prior decades.