Steve Grogan
Grogan was the Patriots’ best quarterback before Drew Bledsoe and Tom Brady. Fans loved him because of his toughness in the pocket and also because of his consistency. Unfortunately, the Patriots suffered a downturn toward the end of his career including a horrible 1-15 season in 1990.
It’s fair to say that Grogan also held on for too long because he became a rotation option. He was unable to irrefutably seal his place as the team’s starter for his final seven seasons. Grogan also threw more interceptions than touchdowns in each of these campaigns (via CBS Sports).