1. Kansas City Chiefs
It should come as no surprise that the Chiefs are the biggest threat to the Bills this season. They're the biggest threat to anybody in the NFL, as the reigning Super Bowl champs and boasting the reigning league MVP in Patrick Mahomes.
Kansas City will probably always be favored, as long as Mahomes is on the field, and no matter who the Chiefs are playing. When it really counts, in the playoffs, Josh Allen is 0-2 versus these Chiefs in his young career. If you think the rivalry between the Bengals and Bills is intense, this one is just as serious.
There really isn't much to say about Kansas City, at this point. We know who they are, and we know what Mahomes is capable of doing. It is looking like a long-tenured stretch of dominance from these Chiefs, assuming no serious injury to Mahomes.
For a long time, it's going to be everybody else in the AFC versus Mahomes. The target is on the back of Kansas City, plain and simple, and the Bills are going to have to figure out a way to knock down Goliath year-in and year-out.