Coach: Sean McDermott (fifth year — 38-26 regular season, 2-3 playoffs).
2020 record: 13-3 (first in AFC East; lost at Kansas City in AFC Championship Game).
Defensive play-caller: Leslie Frazier (fifth year with Bills).
Best player/best newcomer on defense: CB Tre’Davious White/DE Carlos Basham. The NFL’s leader with six interceptions in 2019, White has made two consecutive Pro Bowls and has 15 picks in 61 games. A second-round rookie, Basham had a streak of 23 consecutive games with at least one tackle for lost yardage.
Key statistic: 243 — plays of at least 10 yards allowed last year, most in the NFL.