The Green Bay Packers won the Super Bowl following the 2010 season. That year, the Packers finished 5th in the league in total team defense. The unit featured great players such as Nick Collins and Charles Woodson, and budding stars like second year players B.J. Raji and Clay Matthews.
But the following season, the bottom dropped out. The Packers' defense crashed to 32nd, dead last in total defense, including one of the worst statistical pass defense seasons in NFL history.
Nearly a decade later, the franchise has still not fully recovered on that side of the ball.