There isn't a contemporary NFL quarterback rivalry quite like Josh Allen versus Patrick Mahomes. While the MVP-level signal-callers don't play in the same division, they've made a habit of meeting in high-stakes contests.

Andy Reid and the Kansas City Chiefs confirm Mahomes’ injury status as they prepare for the showdown with the Buffalo Bills.

We break down the biggest strengths and question marks in the Bills-Chiefs matchup, plus the X-factors that could make all the difference.