The league gathered greats from the past six decades including Terry Bradshaw, Jim Brown, Peyton Manning, Tom Brady, Drew Brees, Todd Gurley, Odell Beckham Jr. and many, many more to help kick off its 100th season celebration. A golden ball arcs overhead, a tight spiral sailing across a chaotic scene of upturned tables and smashed champagne glasses, and falls amid a mob of scrambling, muscle-bound actors stuffed into tuxedos. The struggle is harried, but understandable, when the instigator of the scene is taken into account: four-time Super Bowl champion quarterback Terry Bradshaw.”He’s still got it,” a crewmember whispers in awe as Bradshaw tosses another pass across the room.That sort of reverence is shared by everyone who walks onto the set of the NFL’s upcoming Super Bowl spot, a 2-minute ad set to run during this year’s big game that brings together over 50 players to kick off the celebration of the league’s 100th season in 2019. NFL100, as the year-long celebration is called, will officially launch at Super Bowl LIII in Atlanta this week and will be promoted during off-season events such as the NFL combine in February, the draft in April and the Hall of Fame induction ceremony in…