Constructing a competitive 53-man roster as a general manager in the NFL is an inexact science.
Few understand its nuances, and those who get it right deserve to wear white lab coats. The draft requires the GM and his front office to evaluate hundreds of players, narrow the list down to a handful of targets and pray they don't get cut before the season starts.
Free agency isn't any easier. With the fluid nature of contracts and only a 16-game season, NFL rosters go through significant changes year after year. A player's value can plummet so far in a matter of weeks that it's in the team's best interest to let him go midseason, something you can't exactly do in the NBA or MLB.
Though teams can cut their losses quickly, that means a GM's moves have much less time to pan out and that they can follow their failed signings out the door. In fact, nearly one-third of the league has hired a GM since January 2013.
On the other end of the spectrum, doing the job well (or hiring yourself, Jerry) means you never have to look for a new one. By the end of the season, seven GMs will have been with their franchises for at least 10 years and will have accounted for six Super Bowls in that span.
Here are five of the savviest general managers in the NFL, a mix of veterans who have been at it seemingly forever and less experienced guys working toward legendary status.