Perhaps down the road, the Chiefs will become the best team in the NFL again. Right now Kansas City can't make that distinction given how bad its defense is. But the Bills can. They are looking great on both sides of the ball. 

I regard the Bills as the best team in the NF. So I'll gladly accept any points coming to them in this rematch of the AFC title game. The Chiefs were better than the Bills back then. They aren't now. 

The Bills give up the fewest points, yards and passing yards in the NFL. Their offense can trade points against any opponent. 

The Chiefs are potent as ever on offense, although Patrick Mahomes already has five interceptions. Buffalo leads the NFL in takeways with 10. 
Kansas City rates second-to-last in points and yards allowed. The Chiefs have given up 29 or more points in every game. They rank last in yards per play allowing 6.87. The Bills are first in that category holding foes to 4.0 yards per play. 

Buffalo has covered 12 of its last 15 games. The Chiefs are just the opposite going 3-12 ATS. Kansas City also is 1-7 ATS in its past eight home games.