Based on Carl's calculations, the Bills rank 13th because of their opponents' projected winning percentage of .508. But two of their AFC East rivals, the New York Jets (4th, .522) and New England Patriots (6th, .518) face tougher paths. And the other team in the division, Miami, falls in right behind the Bills at No. 14 (.506).
https://www.si.com/nfl/bills/news/bills-schedule-is-13th-toughest-in-nfl-based-on-vegas-win-projections