The Bills posted a helpful infographic on Schwartz to their official Twitter feed:
Both NFL.com's Ian Rapoport and Albert Breer were fans of the move:
Before arriving in Buffalo, Schwartz was the defensive coordinator for the Tennessee Titans from 2001-08. He was then head coach of the Detroit Lions from 2009-13.
He was fired after what was another underwhelming season from Detroit. The Lions were in the driver's seat in the NFC North, but they finished the year losing six out of their last seven games and could only look on as the Green Bay packers won the division.
Schwartz will have his work cut out for him, as Pettine did a great job in his only season as the Bills defensive coordinator. Football Outsiders ranked Buffalo fourth in the league in defensive DVOA (Defense-adjusted Value Over Average).
He'll have a much easier job if the team can sort out the future of Jairus Byrd. The Pro Bowl safety is set to become a free agent this offseason, and there's no guarantee that he'll be back.
Buffalo may have finished 6-10 last season, but the team is headed in the right direction. The pieces are there for the Bills to be a contender in the AFC East next season, and with Schwartz on board, the defense should remain a strong unit.