Pees has had a long coaching career dating back to 1979 when he was the defensive coordinator at the University of Findlay.
Pees spent a lot of time coaching at the collegiate level until he was hired by the New England Patriots in 2004 as the linebackers coach. He eventually became the defensive coordinator in 2006. Then, Pees became the linebackers coach for the Ravens in 2010 and would take over as the defensive coordinator in 2012, replacing the popular Chuck Pagano.
His first season started a roller coaster ride which made Pees the target of much scrutiny and criticism throughout his tenure. The defense was the definition of "bend but don't break" as they were 17th in the NFL, but were able to hold opponents late in games. None more so than in Super Bowl XLVII as the defense made one last stop on the goal line to preserve the win over a surging San Francisco 49ers team.
The good times would not last as the cracks of his defenses showed even more throughout the years and "bend but don't break" was becoming tiresome for fans after 2013, and most especially, after the 2014 Divisional Playoff loss to the Patriots when the defense blew two 14-point leads. Not to mention, many thought last seasons collapse in Pittsburgh was going to be the end for Pees.
A Dean Pees led defense was frustrating to watch because you were never sure if the unit was going to be able to maintain a lead or have a game with the likes of Josh McCown throwing for 452 yards. There was good in his run, like the aforementioned stop in the Super Bowl, or the fact that his defense was able to do something not many teams can do; shut out the Patriots in the second half of the 2012 AFC Championship.
While the 2014 Divisional Playoff with New England gets thrown around a lot, and rightfully so, we forget that Pees bounced back in a big way the week before. Before their Wild-Card Playoff game in Pittsburgh, Steelers quarterback Ben Roethlisberger threw for six touchdown passes in the teams previous meeting with their division rival. With a secondary ravaged with injuries and filled with street free agents, the defense was able to hold Pittsburgh's offense and forced two interceptions on Roethlisberger as Baltimore won their first playoff game in Pittsburgh 30-17.
Even this year has seen it's fair share of ups and downs. While the defense has pitched three shutouts, they still gave up 231-yards rushing to the Chicago Bears at home and couldn't stop the Steelers offense just a few weeks ago.
Pees really does leave behind a polarizing legacy in Baltimore, a city that has been captivated with the play of defense when it comes to Ravens football. The blown leads in big games might be what he will be most remembered for, but he has done a good job developing and coaching up young players like Brandon Williams, C.J. Mosley, Marlon Humphrey, Jimmy Smith, Matt Judon, and others. Those are the players who are going to be the centerpieces and core for this defense for a while, and Pees, for all his faults, deserves a lot of credit for that.