Buffalo leads the league in Yards Per Game (384.0) but struggles significantly against the run, ranking #31 in Rushing DVOA. According to offense.htm, they are relying on short-area efficiency from Shakir while James Cook has emerged as a top-3 league rusher.
Offensively, they use "Everyday Personnel" but vary the tempo. Khalil Shakir is the safety valve, leading the team in targets. Josh Allen has reduced his turnover-worthy plays to a career-low 1.2%, making them very hard to beat via mistakes.
The Bills allow a high 5.1 yards per carry on the ground. They are a "Stuff or Bust" unit—ranking high in tackles for loss but dead last in Explosive Run Rate allowed (13.4%). If you break the first level, there is nobody left to stop the touchdown.