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On Sunday night, the Seattle Seahawks defense put together a historic performance. It was lost in the ugliness of a 6-6 tie, but the Arizona Cardinals had 95 total plays and 46:21 total time of possession, gained 443 total net yards and didn't score a touchdown. It was the longest any NFL defense had stayed on the field without allowing a touchdown in regular-season NFL history, according to the News Tribune's Gregg Bell.

Safety Kelcie McCray led Seattle's defenders with an astonishing 108 snaps (95 on defense, 13 on special teams), and each member of Seattle's Legion of Boom secondary (McCray, Earl Thomas, Richard Sherman and DeShawn Shead) stayed on the field for all 95 plays. To limit Arizona's generally explosive offense to no end-zone appearances with that many chances should be talked about far more than it will be.

Sadly, that superhuman effort was lost in the ugly mixture of reductive play design and execrable offensive-line performance on the other side of the ball.

Let's review four examples of Seattle's current pass-protection issues, starting with this incomplete pass from Russell Wilson to Doug Baldwin. Here, Cardinals edge-rusher Markus Golden moved hard and quickly off the snap, and Garry Gilliam appeared to get into a good pass set. However, he dropped his hands and head and failed to engage through the arc, which is fatal against a guy as talented as Golden. This is the base example of what Seattle's passing offense has become in the last few weeks—quick dump-offs to avoid imminent pressure.

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Then, there was this play with 1:52 left in the second quarter. Defensive lineman Calais Campbell is playing in a wide alignment as opposed to his usual 3-technique spot, and Gilliam can't handle Campbell from the start. He gets a few good steps into the arc and engages Campbell, but Campbell then throws Gilliam aside, because Gilliam doesn't get set and doesn't use his hands to force the action. A man of Campbell's strength will dominate a blocker without fundamental root power every time. To add insult to (psychic) injury, Gilliam is busted for a hold when he grabs Campbell's jersey to save his quarterback.

On the very next play, it was left tackle Bradley Sowell's turn in the bucket. Sowell had edge-rusher Chandler Jones on his left shoulder, ready to rush out of a two-point stance. Sowell tried to get in his set, but his kick-step was slow, and Jones just rushed right by him. Six steps into the play, Jones gave Sowell a hand strike, which rocked him off his point. Jones was able to throw him aside, and this is what it looks like when an offensive lineman is beaten by both power and speed.

The Cardinals were not done with Sowell. Check out this play with 11:51 left in regulation, when Sowell was facing Golden. Right away, it's clear Sowell isn't going to be able to handle Golden's speed around the edge—he's huffing all the way. As Golden moves past Sowell (who doesn't get into the arc at all), Sowell is left to push and flail with no strength from a base. At this point, he's just guessing and holding, and indeed, he's called for a hold on this play.

Russell Wilson finished the game with 24 completions in 37 attempts for 225 yards, no touchdowns (obviously) and no interceptions. Seattle had just 63 plays to Arizona's 95, but if you want to point to Wilson as the root cause of his team's anemic output, that's a bit unfair. Better to lay blame at the feet of the four other guys who matched Wilson's 63-snap effort: left guard Mark Glowinski, center Justin Britt, right guard Germain Ifedi and Gilliam. Sowell would also be a prime offender, though he was injured during the game and played just 39 snaps before undrafted rookie George Fant replaced him.

Wilson, for his part, has looked every bit a top-tier quarterback when his offensive line has allowed him to be. Since the start of the 2015 season, per Pro Football Focus, he's been the league's best deep passer, completing 49 percent of his passes that traveled 20 or more yards downfield (the NFL average is 36 percent) for a league-leading 17 touchdowns. And in his last 12 regular-season games prior to Sunday, his 29-2 touchdown-to-interception ratio and 117.1 quarterback rating also led the league.

Many of those deep throws are predicated on Wilson's ability to improvise after a play breaks down. When he's on the move, Seattle's receivers are trained specifically to find downfield openings in stressed coverages, and it's worked like a charm for the most part.

However, the 2016 season brought a couple of unwelcome changes to the formula. First, Marshawn Lynch's retirement left the Seahawks with a handful of backs with good overall ability, but not Lynch's transcendent knack of picking up chunks of yardage past subpar blocking. Second, Wilson's knee and ankle injuries have robbed him of the ability to move outside the pocket with ease. Thus, there is an offense that must operate more traditionally, with less improvisation, and with an offensive line that's predominantly incapable of sustaining blocks and playing in that more traditional fashion.

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The most glaring place this is showing up? Wilson's deep throws. Through the first four weeks of the 2016 season, Wilson completed 11 of 17 deep passes for 397 yards, two touchdowns and one interception. Not quite the stellar numbers of last season, but at least Seattle was testing defenses deep.

Since Seattle's Week 5 bye, it's been a very different story. Against the Falcons and Cardinals in Weeks 6 and 7, Wilson attempted a grand total of four passes over 20 yards in the air, with one completion for 31 yards. Wilson's percentage of deep throws was 12.8 before the bye; since the bye, it's dropped to 5.4 percent.

Offensive coordinator Darrell Bevell has talked about Wilson's getting the ball out quicker to offset protection issues, which is at least the first step: recognize there's a problem.

"It changes a lot of things," Bevell said last Wednesday, per the team's media department, when asked how a less mobile Wilson alters the overall game plan:

It changes when you're not running, all the styles of runs you can normally have. It changes some of your play actions and your movement game, that kind of thing. Some of the passes we've been using, I kind of think of them as just extended runs a little bit, because you're able to get four-, six-, eight-yard routes in those passes.

These are the kind of adjustments you must make when your quarterback is relatively hobbled, your offensive line (particularly your tackles) is ill-equipped to provide pass protection and defenses know it.

"We've never had two edge-rushers like Chandler [Jones] and Markus [Golden]," Cardinals defensive back Tyrann Mathieu told reporters after that ugly Sunday night game. "Let's call it what it is—their offensive line is not that good. So, we felt like we could get pressure on them, which we did a bunch of times tonight."

Indeed they did. According to PFF's metrics, Sowell allowed a sack, a quarterback hit and a quarterback hurry—again, in just 39 snaps. Gilliam was good for one hit and four hurries, Ifedi allowed one hit and two hurries, and Glowinski had one hit and two hurries. Add in several holding penalties and the general sense that this line looked completely overwhelmed (only Britt has played above replacement level in 2016, and center is the third position he's played in the NFL), and you have the overhead view.

This isn't just a one-game (or one-season) issue. Since 2011, when offensive line coach/assistant head coach Tom Cable came on board, the Seahawks have spent fewer and fewer salary-cap dollars on their offensive line and trusted more and more in Cable's constant assertions that he can take any reasonably sized lineman and make him into something workable. As I've written before, the results have been iffy at best, and with Lynch out of the picture and Wilson less than optimally mobile, more pressure is put on Cable's charges.

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Quite frankly, most of them aren't up to it. Britt looks like a keeper at center. Glowinski and Ifedi are young players with potential. Sowell and Gilliam are projects who regularly show their limitations, and if we're getting forensic, a lot of the problems start right there.

It's not that these players should be specifically maligned. Sowell doesn't have the speed, quickness and recovery ability common in NFL left tackles. Gilliam has raw, base athleticism and little else on a consistent basis. Glowinski and Ifedi are learning how do their jobs at the NFL level, and Britt had to go through embarrassing seasons at right tackle and right guard before finally hitting on a position that works for him.

This, quite simply, is a repeated failure in coaching and evaluation. For that, Cable should be held primarily responsible.

To ensure that my evaluations of Sowell and Gilliam weren't completely off base, I asked Duke Manyweather, the Offensive Tackles Scout for the NFL1000 project, for his thoughts on Seattle's outside pass protection. Duke's take lined up pretty well with mine—and, I'd imagine, many others.

Duke on Sowell: Sowell is a big, long player but lacks the efficiency in his pass-protection footwork needed to set, expand landmarks and consistently mirror defenders on the edge. Sowell lacks explosion into his pass set, and his feet often leave out of position, which forces him to just try to hang on and survive in many situations. He often steps forward before gaining ground, or he doesn't gain ground at all, and those hitches in his movement have made all the difference for pass-rushers to attack his edge and run the hoop on him.

Often, Sowell is so far out of position that it neutralizes his length, and he becomes unable to effectively trace the circle and run defenders over the top of the pocket. Once defenders get him setting aggressively to protect his edge, they convert speed to power and win with the bull rush because of Sowell's lack of overall strength and inability to re-leverage his hips to sit on the bull rush. Sowell also gets caught with countermoves inside because he doesn't maintain a strong inside hand and post-foot.

I've always viewed Sowell as a below-average-to-poor starter and an average backup. There has been nothing in his 2016 performance that would suggest anything different. Sowell's technique, mechanics and body control are past the point of being fixed at this stage of his career.

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Duke on Gilliam: Gilliam creates space off the line, getting to his landmark, and settles his feet on his spot to build his house so that he can make a stand. When Gilliam settles and builds his house, he shows the strike-zone recognition and punch timing needed to stop defenders and leverage with his hand anchor, but he lacks consistency in this area.

Where Gilliam struggles the most is when he gets a defender that wants to play straight through him, and it's not because of a lack of strength to hold up—it's because he plays with an inconsistent base, bringing his feet too close together. This has led to issues with the bull rush, and he's out of position more than you would like when he needs to quickly recover. Gilliam plays with uneven weight distribution in his pass-pro demeanor, which leads him to play with too much weight forward—he becomes top-heavy and susceptible to quick power-escape moves.

Gilliam is effective in slide protection, showing he can work in either direction. Gilliam displays the awareness to identify line games (stunts) and has the range to make up depth relationship if he gets on different levels to pass off the twist—if he sees them early enough. There have been times where he is too far on different levels from his guard and was unable to cleanly pick up the line games.

I'm not ready to give up on Gilliam quite yet. His mistakes are technical nuances that can be developed and fixed. Gilliam shows athletic potential and physicality, which leads me to believe there is still meat left on the bone with his upside.

The issues with the offensive line are especially problematic because in just about every other department, the Seahawks have the obvious look of a perennial Super Bowl contender. Head coach Pete Carroll and general manager John Schneider have built a marvelous talent base. Seattle's defense is indeed historically great. Its young running backs are good enough to help the team win. Wilson has proved he can do just about anything when the play isn't collapsing around him, and Doug Baldwin, his primary target, is the league's best route-runner not named Antonio Brown or Larry Fitzgerald.

Even tight end Jimmy Graham, who was relatively muted in 2015, has come around. But none of this will mean much in the long term if this team doesn't finally realize that going with a patchwork offensive line on the cheap (and forcing young players into situations they're not ready to handle) isn't a sustainable plan for success.

If Sunday night's game doesn't make that obvious to Carroll and Schneider, I'm not sure what will.

Advanced stats courtesy of Pro Football Focus unless otherwise noted.