Jim Schwartz starts over in Buffalo, one of two staff additions announced Friday after the Bills saw their defensive coordinator join the Cleveland Browns.
Schwartz, fire as coach after the Detroit Lions' regular season, joins Doug Marrone's staff as defensive coordinator. That job had belonged to Mike Pettine, now Browns head coach.
MORE: Coaching rumors | Pettine hiring verdict | Dolphins seek GM
Long an assistant with a track record for success, Schwartz enters is 21st NFL season. The Bills also said Friday they hired Todd Downing as quarterbacks coach, according to The Buffalo News.
Schwartz coached the Lions from 2009-13, taking them to the playoffs before his team self-destructed last season. He ran the Tennessee Titans' potent defense from 2001-08 under Jeff Fisher.
Look for Schwartz to switch the Bills to a 4-3 scheme with defensives line up wide to avoid tight end blocks.
"Schwartz has led aggressive and productive defensive units through his time in the NFL and we feel our defense will continue to improve under his leadership," Marrone said in a statement.
Downing worked with Schwartz in Detroit and mentors QB Matthew Stafford. He will turn his attention to EJ Manuel, whose rookie season was aborted by injuries.
While the Lions' offense crumbled in 2013, Schwartz took extra care with the defense. That unit has great success against the run and showed improvement overall.
In Buffalo, Schwartz will have the makings of a strong defensive line, featuring tackles Marcell Dareus and Kyle Williams, and pass rusher Mario Williams.