The NFL’s two best quarterbacks are a combined 14-10 this season. Given everything we think we know about professional football and the role quarterbacks play in a team’s success, it seems unfathomable that the teams led by Patrick Mahomes and Josh Allen could produce mediocre results, but that’s what we’ve seen out of the Kansas City Chiefs and Buffalo Bills in the weeks leading up to Sunday’s game.
Both teams come into the game having lost three of five. Kansas City hasn’t scored 20 points in any of its recent losses, including last week’s surprising loss to the Packers. In Buffalo, defense has been more of the problem, particularly late in games. In both cases, there’s a sense of desperation heading into Sunday. The Chiefs need a win to keep up with Miami and Baltimore in the race for the AFC’s top seed and home-field advantage. The Bills need a win just to stay alive in the wild-card race (according to The New York Times’ playoff predictor, their postseason odds would fall to just 5 percent with a loss). Sunday’s game will be the fourth time Mahomes and Allen will square off in a regular-season matchup. The stakes have never been higher.
Outside of their two playoff duels, this is inarguably the biggest Mahomes-Allen game to date. Yet it doesn’t feel like it, does it? It’s not even the most anticipated game of the weekend. That would be the Eagles-Cowboys game, which also features two of the leading MVP candidates in Jalen Hurts and Dak Prescott (Allen and Mahomes have fallen behind in that race, too). The NFC East clash feels like a summer blockbuster that everyone is lining up to see, while Bills-Chiefs feels like a critically acclaimed melodrama just trying to sell enough tickets to earn back its budget. That’s a bit of an exaggeration, but this game has clearly lost some of its luster.
It hasn’t even been two years since the historic Mahomes-Allen playoff game that stopped us in our tracks. At the time, it felt like these two quarterbacks would put on similar displays every year for the next 15 years. It wouldn’t matter what players were around them; we were in for a show as long as these two meta-humans were on the field. Based on how the Bills and Chiefs have gone about building their rosters since that game, it appears their respective front offices also bought into that narrative. In 2023, we’ve all learned that exceptional quarterback play can take a team only so far.
Statistically speaking, Mahomes and Allen are having similar seasons. Across the board, their numbers are pretty much identical:
Josh Allen Vs. Patrick Mahomes, 2023
They’re even seeing a similar menu of coverages from opposing defenses:
Coverages Faced by Mahomes and Allen
|Cover 1 %
|Cover 3 %
|Cover 2 %
|Cover 4 %
|Cover 6 %
|Cover Zero %
|Cover 1 %
|Cover 3 %
|Cover 2 %
|Cover 4 %
|Cover 6 %
|Cover Zero %
While there are some key stylistic differences between the two quarterbacks, the threat they pose to defenses is essentially the same: Both Mahomes and Allen force opponents to defend the entire width and length of the field and do so for an extended amount of time. Because of that, the responses they see from opposing defenses are also essentially the same.
How Mahomes and Allen respond to those tactics is where we find differences between the two superstars. The former has responded by throwing shorter this season, which has led to more down-to-down consistency and fewer mistakes, while the latter continues to push the ball downfield, leading to more explosive gains and more turnovers. And while Allen and Mahomes are seeing the same coverages, they’re not getting the same results across those splits. Allen has struggled against single-high looks but has eaten up two-high coverages. It’s the other way around for Mahomes. You can even see why this might be the case in their respective heat maps, which show us where Allen and Mahomes have thrown the football this season:
Now compare those to the passing heat maps for the entire league against these common defensive schemes, Cover 2 (a two-high coverage) and Cover 3 (a one-high coverage):
Mahomes’s target looks an awful lot like the leaguewide Cover 3 heat map, while Allen’s looks like the Cover 2 heat map. The Chiefs are beating single-high because Mahomes is hitting the areas of the field that tend to be open against Cover 3, and the Bills are doing the same against Cover 2. While it’s easy to chalk that up to the stylistic preferences of the two quarterbacks, I’m not sure that fully explains what we’re seeing in 2023. After all, this isn’t how these quarterbacks have always played throughout their careers. We’ve seen Mahomes’s average target depth fall over the past few years, but as a young passer, he was throwing downfield as often as Allen has this season. And Allen is trending in the opposite direction, with his aDOT on the rise in the past two seasons, while his initial breakthrough came in seasons when his average target depth was lower.
In both cases, these changes have primarily been driven by personnel changes to their respective receiving corps. In 2022 the Chiefs replaced Tyreek Hill with an assortment of value-brand possession receivers, so Mahomes started throwing short. Buffalo replaced Cole Beasley’s slot targets with Gabe Davis’s downfield targets, so Allen has taken more shots. Mahomes was almost boxed into a more conservative style of play; Allen was boxed into a more volatile style. And while that has led to differences in their underlying numbers, their overall results have largely been the same this season: good but not as great as we expected.
It didn’t have to be this way, though. Both teams made the conscious decision to neglect the receiver position in recent offseasons in favor of strengthening other spots on the offense. Kansas City prioritized bigger and more physical players to improve the run game and invested heavily in the offensive line, and Andy Reid has used bigger personnel on early downs. Looking to create a similar setup, Buffalo used two premium picks on tight end Dalton Kincaid and running back James Cook—players known for their contributions in the passing game. Both teams wanted more versatile personnel to prevent defenses from keying in on the pass.
It’s an intuitive approach but one that ignores an inarguable fact about sports: Talent trumps scheme. While the Chiefs and Bills offenses have become more diverse—in both personnel and formation usage—there has been a noticeable decline in performance at the catch point. That tends to happen when you have nontraditional receivers (like tight ends and running backs) in those spots, as opposed to guys whose main job is to catch a football. While Allen has been the NFL’s best quarterback when throwing into tight coverage, according to PFF’s grading, he ranks seventh in expected points added per play on those attempts. Mahomes ranks in the top 10 in grading on tight-window throws, but his results have been around league average. Compare their performance (by PFF grade) and results (by EPA) to those of some of the leaders:
EPA/Play on Tight-Window Throws
This is where we find the biggest gaps in the performance of sub-elite quarterbacks surrounded by elite receiving talent and that of elite quarterbacks surrounded by average pass catchers. The Bills and Chiefs find themselves in their current predicaments in part because they bought into the quarterback mythology that tells us that a great quarterback will always produce a great passing game. So instead of equipping Mahomes and Allen with more receiving talent—making their respective jobs easier, in theory—they figured that these two quarterbacks were talented enough to do it on their own if they had enough support elsewhere.
It’s hard to knock the Chiefs for this approach. They won a Super Bowl after dealing away Hill and have put the money saved and draft capital gained to good use. The offensive line is better, and the defense is now stocked with young, dynamic talent. But they leaned into the bit too much this offseason by failing to replace receiver JuJu Smith-Schuster, who left in free agency. While Mahomes will always keep the offense afloat, Kansas City is getting close to the limit of his powers.
Meanwhile, knocking the job Buffalo’s front office has done these past few years has been easy. The offensive personnel aren’t any better now than they were two years ago, and the aging defense has predictably fallen apart in the past two seasons. And unlike the Chiefs, the Bills don’t have a shiny Lombardi Trophy to make them feel better about the missteps that have led to this year’s disappointment.
They still have Allen, though. And the Chiefs have Mahomes. That’s the only analysis you need ahead of Sunday’s game. In the past, a Bills-Chiefs contest, with stars and intriguing matchups on both sides of the ball, would require a much deeper breakdown. But Sunday’s game won’t be so complicated. It will come down to which quarterback plays best. It will come down to which quarterback can avoid buckling under the immense weight their teams have placed on their shoulders. For better or worse, that’s how both teams have been constructed.