The new year may invoke the idea of a fresh beginning, but for a certain class of underperforming or unwanted N.F.L. coaches it always means the end.
And so it was as several teams — the Oakland Raiders, the Detroit Lions, the Chicago Bears and the Indianapolis Colts — have fired their coaches and begun a search for a new leader.
The Lions on Monday dismissed Jim Caldwell, who will leave the team despite having a winning record of 36-28 after four years. Within hours, another veteran coach with a notable pedigree, John Fox, was ousted by the Bears.