Why the Chiefs' offensive line has been struggling in recent weeks

The Kansas City Chiefs’ offense is built upon four pillars: head coach Andy Reid, quarterback Patrick Mahomes, tight end Travis Kelce and the offensive line.

For two years, the line has been one of the team’s strengths. Since acquiring left guard Joe Thuney, center Creed Humphrey and right guard Trey Smith, the team has had one of the league’s best interior offensive lines. Then in the past offseason, Kansas City exchanged left tackle Orlando Brown Jr. and right tackle Andrew Wylie for two veterans: Donovan Smith and Jawaan Taylor.

Through the season’s first six weeks, the line played pretty well. It’s true that the running game has struggled all along. The team ranks 20th in rushing EPA — and a ghastly 30th in rushing success rate. But Mahomes’ pockets have been as clean as ever. This season, Mahomes has an average time to throw of 2.95 seconds — the NFL’s sixth-best figure, per NextGen Stats — and the line has given up the NFL’s fewest sacks per game.

But in the last two games, the offensive line has struggled — surrendering four sacks and 19 pressures.

What’s been going on? Let’s look at the film.

Chipping with both tackles

Two weeks ago, I noticed a weird trend starting to happen: on third-and-long, the Chiefs would bring two tight ends onto the field to help both of their tackles. In these scenarios, you seldom see teams use 12 personnel — but Kansas City has now done it numerous times over multiple weeks.

Why are they doing this? Because the Chiefs don’t trust their tackles.

Kansas City paid Taylor a lot of money to be a tremendous pass protector — but over time, the team is relying on him less often. While Smith isn’t earning as much, the team has slowly lost trust in him, too.

This is alarming.

It’s not costly to help one tackle with chip blocks — but when a team helps both tackles, it hurts the passing offense. This is especially true for the Chiefs. Since the team’s wideouts lack the speed (or perimeter talent) to win with three routes, the team doesn’t have the luxury of using two potential receivers for chip blocks. But even when teams are sending only four rushers, Kansas City has been committing to helping both tackles.

Picking up stunts

In the last two weeks, the Chiefs have also somehow forgotten how to deal with twists and stunts. Both the Miami Dolphins and Denver Broncos ruthlessly attacked Kansas City with different plans to confuse the offensive line.

In particular, the left side of the offensive line hasn’t been able to figure these stunts out. Smith and Thuney have blown multiple assignments on simple TE stunts — where the defensive tackle spikes upfield with a looping edge rusher — in multiple weeks.

The strip sack that Mahomes had on Sunday was another miscommunication.

This is entirely fixable — but it needs to happen quickly. The Chiefs need to spend this bye going over all their protection rules for a simple reason: this is on tape now, so teams will try to run more stunts against the offensive line. It’s going to have to be ready to sort those out.

Running into light boxes

What’s maddening about the running game is that Kansas City is getting great looks. Both the Broncos and Dolphins deployed light boxes that used 5-1 fronts to help defend against Kansas City’s RPO plays. By pushing a defender out to deal with the passing part, that consistently left light boxes — and yet, the Chiefs couldn’t take advantage.

There are many issues here. Some involve play-calling. Running outside zone runs from a shotgun is very difficult against a 5-1 front. I’d argue, however, that the execution had been a bigger problem. The Chiefs’ tackles — particularly Smith — are poor run blockers. They consistently miss assignments and have difficulty getting displacement off the edge. Smith especially struggles to deal with defensive ends one-on-one.

It’s bad enough that the two tackles aren’t positive run blockers — but the interior is playing worse, too. Thuney has struggled to gain much movement on his zone blocks; he’s consistently getting moved backward. Even Trey Smith and Humphrey are struggling to be consistent run blockers.

Overall, the Chiefs’ offensive line is getting massacred in the running game — and considering the unit’s reputation, this is unacceptable.

The bottom line

Kansas City has invested way too many resources — and has acquired too much pedigree — for their offensive line to be this bad. For a team that primarily passes the ball — and for most of the season — the line has been a strength. But the past two weeks have been a total mess.

Picking up stunts is entirely fixable. The running game, however, is a bigger concern. When the team switched tackles, it sacrificed the line’s run-blocking ability in order to get better pass-blocking. The Chiefs are just going to have to find a way to compensate for their tackles in the running game.

I’m very worried about the play of the offensive tackles. I thought Smith and Taylor had great games against the Chargers — but the last two weeks have been dreadful. When you’re putting in two tight ends to chip on third downs, it’s a problem. The tackles have to play better. Otherwise, it’s going to be difficult for Kansas City to move the ball on third down.

Hopefully, the team can get these under control during the bye week — because if this is how their offensive line is going to perform in the stretch run (and the playoffs), the Chiefs will have no shot.