Even Bellichek proves you can't win with a bum QB in this modern era of no-defense. If it weren't for the move to Baltimore mid-season, Bill was on the verge of pulling a Jimmy Johnson resurrection of the Browns, as they were improving every year without modern free agency. They were 11-5 the year before, with Vinny at QB and he had the number 1 ranked defense, 7-9 the year before, 7-9 a year before that and 6-10 to start BBs HC career. They started off 3-1 the season they announced the move, even and then "rumors" started floating around that the team was moving and nobody knew the state of the franchise. Their minority owner was prodding Modell to move and it was announced in November they were bouncing.
When Brady left that year, they were also horrible offensively, stats were grossly over-exxagerated because they had the number 1 ranked defense and 37th TOs generated. ANybody could see the writing on the wall. He still won 10 games with Mac Jones in his rookie year and 8 the next year, but they had no WRs. Plus, BBs right hand men left basically the same time as Brady, Ernie Adams and Dante Scarnechhia. He did fine with Casell and his other QBs when Brady had the ACL tear. The first few SB wins werte definitely defensive dominance. HIs defensers regularyly massacred Manning in the playoffs.