It’s Year 3 and the NFL is still desperately trying to figure out how to stop Patrick Mahomes. Defenses are throwing whatever they can at the wall and hoping something sticks. Hope is all they really have at this point.

Through 14 weeks, Mahomes leads the NFL in passing yards by 507 yards above second-place Deshaun Watson. There’s a bigger passing yards gap between Mahomes and Watson than between Watson and Ben Roethlisberger, who ranks 14th. Mahomes is also first in passing Expected Points Added, according to Sports Info Solutions, and is the only quarterback with at least 100 attempts who has produced positive EPA on at least 60% of his passes.

The combination of Mahomes, Andy Reid as a play designer and caller, and Kansas City’s receivers makes the Chiefs nearly impossible to cover. This season, defenses have hoped to prevent the big passing play by using two deep safeties. This started as early as the opening game of the season when the Houston Texans opened with deep coverage looks and Kansas City adjusted by throwing short and quick.

Mahomes already has more dropbacks against two high safeties than he had in either full season of 2018 and 2019. It’s also the first season in which Mahomes has faced more two-deep coverage than single-high safety looks.

Patrick Mahomes Dropbacks By Post-Snap Safety Alignment

Yearvs Single Highvs 2 High

Many opponents have gone out of their way to play more 2-high coverage against the Chiefs this season. Four opponents have played at least 20% more two-deep looks than they have against non-Kansas City opponents. Another four used 2-high coverages against the Chiefs than they have against other opponents, but all four were within 3% of their season averages and looking back. Those were also the four teams with the lowest 2-high percentage against the Chiefs and all four were only able to hold up for so long with that plan, some a little better than others.

Chiefs Opponent Two-High Rates, 2020

Team2 High % vs KC2 High % vs non-KCDiff%

The Buffalo Bills and Los Angeles Chargers had two of the biggest shifts for the Chiefs and both were able to keep games somewhat close. Buffalo kept two deep and a light box up front in order to dare Kansas City to run. The Chiefs obliged but the Bills couldn’t stop them on the ground. The Chargers were able to use that deep coverage and add on with four-man pressures that allowed for more coverage on the second level. They were also able to go deep shot for deep shot with Justin Herbert on offense. And just by keeping the game close, that still left a chance for the Chiefs to pull away at the end of the game.

If the goal of this two-high coverage is to suppress the big play, it hasn’t exactly been working as planned. Mahomes’s numbers are significantly different when facing single-high or two-high safeties this season.

Patrick Mahomes vs Safety Alignment, 2020

Deep SafetyOn-Target %Comp%YPATD%INT%Sack%

Mahomes has thrown deep less often overall and that rate has dropped each season since 2018 from 14.1% of his attempts to 12.8% last season and 11.3% so far in 2020. While the two-deep alignment has been used to stop the deep pass, Mahomes has been surprisingly better on throws of at least 20 air yards against those coverages than when there is just a single safety deep — though six of Mahomes’s seven deep completions against single-high looks have been touchdowns.

Patrick Mahomes 20+ Air Yard Attempts vs Safety Alignment, 2020

Deep SafetyAttCompYardsTD/INTEPA/Att

The coverage changes aren’t so much about if the Chiefs will beat the defense but more so how the Chiefs will beat the defense. That’s the problem with stopping the Kansas City offense, solving one problem creates another. This is incredibly oversimplified, but Tyreek Hill has been able to feast on single-high coverage and when the Chiefs face two-high safeties, it’s time for Travis Kelce. 

Against single-high coverage, which typically leaves Hill one-on-one on the outside, he’s been able to hit those big plays. Hill is 35th among NFL players in targets against single-high coverage this season (49) but only Davante Adams and Adam Thielen have more touchdowns (10) than Hill’s seven.

Even the best corners in the league haven’t been able to hold up and few safeties have the range to get from the middle of the field over to the sideline in order to catch Hill on the outside. Take the Tampa Bay game when the Buccaneers tried to run their typical defense, but even Carlton Davis, who had played like one of the better corners in the league, could only do so much in man coverage.

In that game, Hill had six receptions on seven targets for 188 yards and three touchdowns against single-high coverages. The Buccaneers quickly avoided that plan and spent the rest of the game with two deep safeties, resulting in one of the higher rates shown above.

Kelce, meanwhile, is the most targeted player in the league against two-high safety coverages (61 targets). His 684 receiving yards are 234 more than the next highest receiver, who happens to be Hill (54 targets). Kelce’s ability to work the intermediate middle of the field when the safeties are playing deep has been a huge part of the Kansas City passing game this season and a big reason why the tight end currently leads the league in receiving yards with a 70-yard lead over D.K. Metcalf, a player who has needed single coverage to thrive this year.

Between Kansas City’s route concepts and Kelce’s run after the catch ability, he’s been one of the more productive receivers after the catch even with more defenders back in coverage. Among players with at least 20 receptions against two deep safeties, few are able to match Kelce’s combination of air yards and yards after the catch per reception.

The Chiefs have been able to kill the intermediate area of the field this season against all coverages and that’s why even though Mahomes’s average depth of target has dropped in each of the past three seasons from 9.2 yards in 2018 to 8.6 in 2019 and 8.5 so far in 2020, his average depth of completion has stayed nearly identical — 6.4 yards in 2018, 6.2 yards in 2019, and 6.5 yards in 2020, according to NFL Next Gen Stats.

Mahomes’s shorter passes have also helped to create more open throws, an insane revelation for an offense built around them. Mahomes has thrown into a tight window on just 10.9% of his attempts in 2020, down from 12.2% in both 2018 and 2019 which was already one of the lowest rates in the league.

For as much as defenses have tried to vary gameplans against the Chiefs, the best defense this year has been an offense able to keep up. That’s how the Raiders gave the Chiefs their lone loss. It’s how the Chargers were able to hold on just long enough. It’s also why the Bills couldn’t run away with their lead at the time and why the Dolphins couldn’t take advantage of three interceptions.

Buffalo might still present the most interesting test as a team that figured out how to slow down the offense, but couldn’t stop the run when they dared the Chiefs to do it. But since that game, the Bills’ run defense has improved (20th in run defense DVOA from Weeks 1-9 and ninth since Week 10), which could limit the damage done on the ground, though it’s no guarantee Kansas City would give in to the light boxes again. But the Bills’ pass defense has also improved after a rough start and on its best day, the Buffalo offense has the ability to put up points.

Still, we’re talking about everything breaking just right for a team to defend and hang with the Chiefs. It’s not impossible, but even without blowing teams away, Kansas City has made it as hard as possible to take them down.