Last offseason, I wrote about how the Seattle Seahawks would look to fix their run defense, which was a mediocre 17th in DVOA and the worst of the Pete Carroll era.

Well if they did aim to fix it (and I’m sure they did), they have failed spectacularly.

Thanks to last Sunday’s 253-yard gashing by the Arizona Cardinals, the Seahawks dropped to 26th in run defense DVOA, and at -1.1% they are almost certainly going to be the worst run defense this team has fielded since 2006. By pure coincidence, that injury-riddled Seahawks team got into the playoffs with a negative point differential, which is very possible for this year’s team.

Now you may be thinking, “They’re that bad? But how? They’ve held their opponents to less than 100 yards eight times this season, and only Kenyan Drake, Nick Chubb, and Lamar Jackson were able to rush for more than 100 against this run defense!”

Well yeah, but DVOA obviously doesn’t work that way, which is one of the great things about advanced metrics because it helps contextualize the basic counting stats that NFL broadcasts still use as primary measurements of good and bad. Even DVOA is not infallible, as early-season stats can often be useless without adjusting for opponent, as indicated by the Seahawks having a top-ten run defense in September and Baltimore being near the bottom of the league.

You see, the run D has been hidden from the stage thanks to a neat little trick. That “trick” is simply Seahawks opponents not running the ball all that much. Seattle’s defense has only faced 364 attempts on the season (seventh-fewest in the NFL) and rushing plays on 37.7% of all snaps, which is fifth-fewest. I suspect that the lack of pass rush and the early-season awfulness of the secondary inspired a lot of the pass-heavy attacks we’ve seen.

They are 26th in expected points added (EPA) at -9.05, although they do have two playoff teams worse than them in the Green Bay Packers (28th) and Kansas City Chiefs (31st). Both of those teams offset the run defense issues by having substantially better pass defense both by DVOA and EPA.

For the second year in a row, defending the early down runs have been a huge issue. They’re statistically a little bit better than 2018 but their ranking is slightly worse.

Seahawks run defense on early downs (2010-2019) Year Rate of 1st downs allowed League ranking Year Rate of 1st downs allowed League ranking 2010 18% 12th 2011 18.50% 11th 2012 20% 16th 2013 17.40% 08th 2014 15.50% 02nd 2015 18.90% 10th 2016 17.60% 03rd 2017 18.30% 12th 2018 23.30% 21st 2019 21.40% 22nd

Those dreaded “explosive plays” that Pete Carroll loves to limit have been blowing up the entire Seattle defense, but to focus just on the running game, they have allowed 51 plays of 10+ yards, a pitiful 26th in the NFL. Nearly 14% of all rush attempts have yielded a double-digit gain for Seahawks opponents. To compare that with the #1 Tampa Bay Buccaneers, they’ve only allowed 30 explosive runs on 332 attempts, which is below 10%. Or for something more familiar, the 2013 Seahawks allowed 48 explosive runs but on 422 attempts and finished 7th in DVOA.

In the high-variance region known as “Goal-to-go Land,” the once-stout Seahawks defensive front has folded like a lawn chair. Out of 27 rushes in goal-to-go situations, Seattle has allowed 13 touchdowns and are only worse than the historically bad Carolina Panthers. Their red zone rushing success rate is also just 24th.

We’re this deep into the article and I’ve not mentioned their horrendous job defending wide receiver jet sweeps, or the rather curious statistic that shows opposing running backs have had a greater success rate attacking Jadeveon Clowney’s preferred side of the field.

There seems to be an easy answer that explains away the struggles of the Seahawks run defense (and a lot of overall defensive struggles). As it turns out, Michael Bennett, Frank Clark, Cliff Avril, etc. are indeed better than this entire Seahawks defensive line put together. This doubles for the secondary, which had Kam and Sherm making phenomenal run-stopping plays. It wouldn’t be all that interesting to just write “Seattle’s defense is bad because nearly all of the great players were replaced with worse ones,” would it?

As for the specific Xs and Os of what’s caused this collapse, that’s not my alleyway. The splash plays that Poona Ford and Rasheem Green have made are nice yet obviously not frequent enough as a whole. What I do know is that Jarran Reed, Jadeveon Clowney, Ziggy Ansah, Al Woods, and Quinton Jefferson are all unrestricted free agents this offseason. We could be looking at a very different defensive line in 2020, and perhaps it may be welcomed. You can point to the injuries of Clowney and Ansah and the suspensions of Reed and Woods as key culprits, but the front four has been almost a total failure, which is unfathomable for a Carroll defense.

There are serious flaws just on the defensive side of the ball alone that need serious addressing in 2020, but as for 2019 we’ll just have to live with what they are and hope they’re not fatal flaws in the postseason.