Prior to the one-year stint in Washington, Ryan served as the Buffalo Bills' assistant head coach/defense in 2016 under his brother, Rex Ryan, but the siblings were each relieved of their duties following a Week 16 loss to the Miami Dolphins.
Buffalo ranked eighth in the NFL in sacks that season with 39, but it finished only in the middle of the pack in terms of both points and yardage allowed. The Bills were especially poor at stopping the run, as they were 29th in rushing yardage surrendered and 31st in rushing touchdowns against.
According to Pro Football Talk's Michael David Smith, Buffalo gave up the NFL's three biggest individual rushing performances in 2016:
Ryan had little success in his dozen years of running defenses. His defenses ranked inside the top 10 in total defense on just two occasions, while they ranked 27th or worse six times.
Although Ryan is lacking in terms of production, he does have a great deal of experience and comes from a coaching family. His late father, Buddy Ryan, led the Chicago Bears' vaunted defense in 1985 and also served as a head coach with the Philadelphia Eagles and Arizona Cardinals.
While Ryan's results suggest he shouldn't be in charge of running defenses, his lengthy resume could make him a valuable staff addition in a lesser role.
He won a pair of Super Bowls as the New England Patriots' linebackers coach from 2000 to 2003, and he will bring that winning resume to a Baltimore team that has struggled to achieve postseason success in recent years.