Could Chiefs transition to a different blocking scheme in 2021?

Did the Chiefs overhaul their offensive line to run more gap schemes going forward?

After the conclusion of the 2020 season, general manager Brett Veach and the Kansas City Chiefs front office wanted to make sure they fixed their offensive line woes. Injuries were present at both tackle positions and there were more questions than answers along the interior. Patrick Mahomes had games that required running for his life before the Tampa Bay Buccaneers took advantage of a makeshift line in Super Bowl LV.

While most expected the Chiefs to make a concerted effort to revamp the offensive line this offseason, the way that they did it raised questions for those following closely. Head coach Andy Reid has largely implemented a zone-heavy rushing attack in his time in Kansas City but the recent acquisitions show a trend toward blockers who fit a gap or power rushing attack.

Were these additions an indicator of a shift in the Chiefs rushing philosophy? Did the offense’s relative lack of success in short-yardage situations force their hand toward these types of players?

Here we’ll take a look at the differences between zone and gap responsibilities — along with the merits of each — before diving into the Chiefs’ newest additions to highlight ways they could fit in a revamped gap rushing attack.

Zone vs. Gap Philosophy

While zone and gap schemes aren’t exclusive in their personnel, there are some key differences between the two approaches. Zone schemes typically look for agile, movement-based offensive linemen who can combo block and climb to the second level quickly or reach across the face of the defender to seal from the play-side gaps. Because these zone-heavy schemes don’t typically require offensive linemen to drive a defensive tackle off the line of scrimmage by themselves, zone schemes can get by with lighter players who may not have top-end strength and power.

Gap schemes, meanwhile, rely much more on individuals to create movement in one-on-one matchups. That means individual players are relied upon to win their matchups up front through strength and power to blow open a gap for the running back. Gap schemes do still require movement ability — many gap concepts have a pulling blocker of some kind — but the ability to reach a blocker a gap away isn’t as important as it is in zone schemes.

Another difference between the schemes is how the gaps are opened up for the running back. In a zone scheme, the running back is responsible for reading multiple gaps from which to choose based on the leverage of the blocks and where the defenders are filling. Since the running back has multiple reads, offensive linemen have to make sure to keep gap integrity and open up the correct lanes for the back. That can make for some hesitation by the offensive line to drive a defender off the ball or into another gap for fear of closing the only available read for a running back.

Meanwhile, a gap scheme is focused on a singular gap — typically with a cutback lane available if the defense overcommits — for the offensive line to attack. Pulling blockers are designed to send numbers at defenders in the chosen gap, blowing it open and creating the biggest singular running lane for the back to attack. Because the gap is pre-determined, it allows the back to play faster and the offensive line to maul and drive players off the spot without the worry of muddying one of the back’s reads.

Neither scheme is necessarily better than the other. Zone schemes have the advantage of forcing the defense to play gap-sound football at all times to plug multiple gaps along the front. A single missed assignment by the defense — and a running back with the vision and agility to exploit it — can result in a big play for the offense. On the other hand, gap schemes allow the offensive line to impose its will and demoralize a defensive front. A unified group of powerful offensive linemen in a gap scheme is not only difficult to defend due to its moving pieces and misdirection, but it can also wear out the defense quicker and make them play slower when trying to read their keys.

Similarly, both schemes have their deficiencies. Since zone schemes require reading and reacting to the defense to adjust blocks off the snap, plays can develop slower and can lead to struggles in short-yardage situations where the defense is shooting hard into the backfield. Gap schemes, on the other hand, can struggle if everyone isn’t on the same page or if an individual piece can’t handle the defender in front of him. The play is designed for a specific gap, meaning a single missed assignment or miscommunication of a run blitz can have a domino effect that results in a negative play.

How do the new pieces fit?

The Chiefs went out of their way to add a whopping six offensive linemen this offseason to their roster. Of those six, four of them — Orlando Brown Jr., Joe Thuney, Creed Humphrey and Trey Smith — are terrific fits for a gap scheme. All four are powerful players with good core strength to turn and peel defenders out of the gap, and all four have shown the ability to pull into the gap and eliminate defenders, as the above video demonstrates.

Smith didn’t have a ton of reps in gap concepts at Tennessee, but the other three come with plenty of experience in those schemes. Thuney comes from one of the best gap/power rushing offenses in the league in New England and played both center and guard — showing his understanding of the adjustments and protections needed to run the scheme. Brown also played in a strong gap rushing scheme in Baltimore that put him on the move as a wrapping blocker regularly. He also played in Lincoln Riley’s gap-heavy Oklahoma offense.

Humphrey, meanwhile, might be the best fit of the group, as he called run and pass protections for that same gap-heavy Oklahoma offense. He saw a litany of defenses in the Big 12 and had to make adjustments to the blocking scheme against very diverse fronts that are becoming more prevalent in the NFL. Putting Humphrey at the helm immediately — and trusting him to make the calls in a veteran group — could signify the addition of more of these gap concepts for the Chiefs.

The other new additions — Kyle Long, Lucas Niang and Austin Blythe — are all average fits within a gap scheme, and only Niang has a serious investment behind him at this point. They are all smart and capable enough to execute the assignments required, especially when attached to multiple other offensive linemen tailor-made for the scheme.

The verdict

It’s hard to see Reid ever fully abandoning a zone rushing attack, and the Chiefs will likely still run more zone concepts than gap concepts in 2021 — of which this offensive line is still perfectly capable of executing. However, the new additions from the Chiefs scream that this team wants to have the flexibility to run more gap concepts in the future.

Reid has watched the collegiate game transform to more gap schemes without sacrificing elements of the spread offense, particularly from Riley’s Oklahoma teams from which Humphrey and Brown both matriculated. As defensive coordinators move to lighter defenders and more defensive backs on the field to counter the Chiefs’ high-octane offense, incorporating some bruising, powerful run schemes only makes sense.

The Chiefs new offensive line will surely protect Patrick Mahomes better than they did in 2020 in the passing game. However, the addition of these new players — and the potential for a more diverse rushing attack — might be the element of the 2021 Chiefs offense that keeps defensive coordinators off-balance all year.

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Craig Stout grew up as a defense-loving Chiefs fan during the Marty Schottenheimer years. His thirst for knowledge found him delving into the Xs and Os of modern defense to better understand how to stop today’s offenses. He’s been breaking down the Chiefs scheme through the Pendergast, Crennel, Sutton and Spagnuolo defenses.