Chiefs vs. Bills: Week 5 Preview and Prediction

Here's everything you need to know before the Kansas City Chiefs take on the Buffalo Bills on Sunday night.

This Sunday, the Kansas City Chiefs will be back in prime time, facing off against the Buffalo Bills in an AFC Championship rematch in Kansas City on Sunday Night Football. The Chiefs currently stand at 2-2, following a victory against the Philadelphia Eagles, while the Bills are 3-1, following a victory over the Houston Texans.

Bills quarterback Josh Allen will attempt to avenge his AFC Championship loss to the Chiefs last season when he had a 39th percentile -0.4 Expected Points Added (EPA) and Mahomes had a 97th percentile 23.3 EPA. Allen must put on a much better performance in this game, but, unfortunately for him, he is not looking like he did last year to this point in time. 

Fact to Know: Josh Allen has not been nearly as good this season as he was last year.

CPOE = Completion Percentage Over Expectation (Completion Percentage minus Expected Completion Percentage)

Allen has taken a big step back in his quality this season so far, ranking 23rd in EPA+CPOE composite after ranking third last season and 20th in overall grade from Pro Football Focus (PFF) after ranking fifth last season. It is not a total shock, as his jump in production from two bad seasons to one fantastic season was one of the most surprising positive progressions in NFL history, but it is a disappointment with how fun of a player Allen is and how incredibly he performed last season.

Matchup to Watch: Tyreek Hill vs. Tre'Davious White

This is a pretty obvious choice to make, as White is one of the most touted cornerbacks in all of football and is consistently on the opposing team's best wide receiver, where he will clash with their top target all game long. In this game, that obviously has to be Tyreek Hill. 

In last season's AFC Championship game, Hill had himself a game, going for 172 yards and six first downs over 11 targets. White, while he was the most targeted cornerback against Hill in the game, allowed just 30 of those yards, but still two first downs over four targets. Hill's main production was against Taron Johnson, who he got 90 yards and two first downs over three targets against. While Hill may still get his best production against a defender other than White on the Bills, he will still be facing White most of the time and he has shown he can produce against White. It ought to be quite the matchup and it could determine the outcome of this game if Hill can get separation to make a couple of big plays or if White completely shuts Hill down.

Key to the Game: Break the Bills defense

The Bills have the league's best defense so far this season, allowing a league-low 44 points total through four games, having the highest team-defense grade on PFF and earning a laughably incredible Dropback EPA allowed per play of -0.352 with no other team even reaching -0.120. This has made up for the worsened offense, which has gone from fourth last season to ninth this season in Offensive EPA per play, and it could be something that puts them over the top as a championship contender.

However, there's an elephant in the room: the Bills have played one of the worst quarterback schedules possible to this point. The Bills have faced Ben Roethlisberger, Jacoby Brissett, Taylor Heinicke and Davis Mills. Look at the chart below and see where each of these players rank.

Heinicke is by far the best quarterback they have played this season, with the other three being among the five worst quarterbacks in EPA+CPOE composite, with Heinicke ranking 10th with a 0.166 EPA+CPOE composite. Patrick Mahomes is first with a 0.260 EPA+CPOE composite and the only other quarterback even close is Kyler Murray with a 0.243 composite. The Bills are going from seeing three of the five least-productive quarterbacks in football in four games to seeing the most productive quarterback in the history of the game. Will this finally be the moment that the Bills' defense is taken back down to earth, or will they prove the skeptics wrong? 

Prediction: Chiefs 31, Bills 27

As previously mentioned, this is a rematch of last season's AFC Championship Game, and it is very possible that it will be a preview of this season's AFC Championship Game too. The Bills' incredible defensive production to this point and the pure talent of Josh Allen and Stefon Diggs makes this team one of the best in all of football, but the Bills' schedule to this point puts pause to believing their defense is actually the best in the NFL. Plus, Allen and Diggs have had a slow start to the season, making this matchup much easier to expect a Chiefs victory from. I expect a two- or three-touchdown game for Mahomes with Travis Kelce being dominant and Hill putting up a couple of the biggest plays of the game. The Bills ought to be competitive and they will likely have plenty of highlights on both offense and defense, but I am not going to go against Mahomes when he is playing as well as any quarterback this season, while you could argue Allen hasn't even been a top 20 quarterback so far this year.

For more Kansas City Chiefs analytics and analysis, follow @SIChiefs and @WichitaChiefSam on Twitter.

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