The NFL has changed over the last decade, and teams are only as good as who they have under center.
While it may be hard for teams to convince talented quarterbacks to assume a backup role, when they can it pays off for both the team and the player.
Despite having 10-plus wins, the Patriots missed out on the playoffs but Cassel was more than competent in his audition for a starting job.
Cassel was traded to the Kansas City Chiefs the next season and has assumed the starting role since.
Having a solid No. 2 QB could be the difference for a team on the border between making the playoffs or sitting on the couch watching them.
Here are the rankings of each team's backup quarterback situation.