Film Room: Bills Offense vs. Chiefs Defense

Somehow, both conference championship games this weekend are rematches of games played in Week 6. The Buccaneers blew out the Packers in 38-10 fashion down at Raymond James Stadium, while the Chiefs battled past the Bills with a 26-17 win. Whether or not the results of each game will change, who knows, but all four teams have evolved and neither game should play out the same.

The Bills-Chiefs matchup is especially primed to unfold differently from the first meeting. While both teams have ebbed and flowed, as teams do throughout the season, the Chiefs' pass defense in particular has definitively gotten worse since midseason. The Chiefs ranked sixth in pass defense DVOA through the first nine weeks of 2020, which included their win over Buffalo in Week 6. From Week 10 through Week 17, however, the Chiefs plummeted to 29th. Nobody could really keep up with the Chiefs in a shootout, so it mattered very little in terms of wins and losses, but that may not be the case on Sunday.

On the one hand, the Chiefs play a similar style of defense to the Ravens, who held Allen in check last weekend. Both defenses blitz at a top rate, love press-man coverages, and often rotate from one-high to two-high looks because the talent they have at safety allows them to get away with it. The Ravens are a tad blitz-happier and less likely to mix in Cover-2 the way the Chiefs do, but the overarching themes of each defense aren't too different.

On the other hand, Allen has largely been a menace against man coverage this year. Through the regular season, Allen finished second in success rate against man coverage, sandwiching himself between Aaron Rodgers and Patrick Mahomes. That's pretty good company. While the Ravens' heavy usage of man coverage kept Allen quiet on Sunday, that had much more to do with the Ravens' cornerbacks playing lights-out than it did with Allen struggling. The Chiefs simply do not have cornerback talent like that.

The numbers and highlight throws speak for themselves as far as Allen's play vs. man coverage goes, but part of Allen's success against man coverage is his ability to run. He can be his own checkdown. Man coverage across the board usually means defenders are going to have their back turned and/or be locked into their receiver. Players with Allen's speed will take advantage of that all day if you let them.

On this third-and-5 from Week 6, the Chiefs start with a zero-safety look before bailing to two-high right before the snap. With a cornerback lined up over every receiver in press, Allen can take this snap feeling good about man coverage being deployed. Allen hangs in for as long as he can, but the pocket begins to collapse, forcing him to bail. Tyrann Mathieu (32) was able to vacate his man assignment because the tight end on the offense's right stayed in to block, freeing Mathieu to become a late rat/robber, but not even he could fly over to the perimeter fast enough to catch Allen in time before he reached the sticks.

Even when the Chiefs were in the perfect call, it was not always enough to contain Allen. In this clip, the Chiefs are in man coverage again, but they have a built-in trips adjustment for how they want to handle the weak-side (right) No. 1 receiver going underneath immediately. Charvarius Ward (35) lines up across from that receiver at the snap, but rather than sprinting after him, across the field, Ward gives a call to the weak safety (Mathieu, 32), allowing him to fly down to cut the crosser off at the opposite hash. The cornerback then falls off to replace the safety deep. This can be a great adjustment with a good weak safety because of how favorable his leverage is as opposed to the cornerback's. Alas, while the adjustment works against the route it was designed to stop and the rest of the coverage holds up, Allen just takes off for 10 yards and converts the first down anyway.

The Chiefs will try to do this versus a number of different looks, though, not just when it's an under route by the solo receiver in 3x1. Just last weekend, the Browns caught the Chiefs on a beater for this kind of adjustment with the Chiefs trying to defend a bunch trips formation this way. In short, this Chiefs adjustment is best when the cornerback falling off to replace the safety has routes breaking into him, such as corner routes or crossing routes from the other side of the field like in the last clip.

Cleveland's fix was to run none of their routes into the cornerback falling off. The rest of the Browns' routes from the trips (right) side in this concept break to the middle of the field, where the safety (Juan Thornhill, 22) is vacating in order to drive down on the under route. Sure, it takes some degree of luck to catch the Chiefs in this particular call, but if an offense knows the Chiefs like doing this, especially against 3x1 and/or on third down, they can call beater concepts like this to throw behind the vacated safety and away from the dropping cornerback.

Buffalo offensive coordinator Brian Daboll is plenty sharp enough to come up with some solutions of his own, whether it's to this specific coverage or any of the Chiefs' other man coverage calls. Over the past few weeks, Daboll has done an especially good job of doing so. He even worked up some nice answers to man coverage against the Ravens in the opening drive of the second half, despite the offense not doing much else besides that.

Bills opened the third quarter doing everything they could to create traffic for the Ravens' man coverage. Struggled to get any of this going in the first half. pic.twitter.com/FUYVVAj7gi

— Derrik Klassen (@QBKlass) January 18, 2021

This series of plays was from Buffalo's lone touchdown drive against the Ravens. All throughout the first half, the Bills kind of ignored a lot of these rub routes in favor of trying to beat the Ravens in other ways, but eventually leaned on them for this drive to finally put some points on the board. With the Chiefs being as man-coverage heavy as they are, they will be just as susceptible to concepts like this as the Ravens were, especially with how they have been playing as of late.

As a final aside, the Bills will also be working with right guard Jon Feliciano in this game. Feliciano missed the first seven weeks of the season, which meant he was not there for the first iteration of this matchup. Not only is Feliciano a quality blocker in both phases of the game, but he does a lot to help Allen and center Mitch Morse with protection calls and the like. It's a group effort in Buffalo, and not having one of the brains to their operation up front certainly hurt them a bit. Having Feliciano back in the lineup since Week 8 has done wonders, especially over the past six weeks or so as the unit has really gelled again.

None of this is to say the Bills will beat the Chiefs this time around. Betting against the Chiefs just feels wrong, especially if Mahomes is at or close to 100% when this game kicks off. The Bills may be able to force more of a shootout and give themselves a better chance than they did in their last meeting, though. Against the juggernaut that is the Chiefs since 2018, that is about the best that any team can hope for.