One No. 12 started the clock on the countdown to his gold jacket and another switched numbers, conferences and shades of green.

The biggest storyline in the first NFL season this century without Tom Brady centers on Aaron Rodgers’ quest to turn the New York Jets into a championship contender. The 39-year-old, four-time NFL MVP left Green Bay for a team that hasn’t reached the playoffs since the 2010 season and hasn’t won a Super Bowl since Broadway Joe Namath guaranteed one more than 50 years ago.

Rodgers has plenty of talent surrounding him but the Jets play in one of the toughest divisions in the league and a conference loaded with contenders, including the defending Super Bowl champions.

Patrick Mahomes and the Kansas City Chiefs are aiming to become the first team to win consecutive titles since Brady led the New England Patriots to back-to-back rings in 2003-04. The Chiefs have dominated the AFC West under coach Andy Reid, capturing seven straight division crowns and hosting five consecutive conference championships.

Plenty of teams are standing in Kansas City’s path to another deep run in January.

Joe Burrow and the Cincinnati Bengals are primed to return to the Super Bowl after falling short two years ago. Josh Allen and the Buffalo Bills are under pressure to get there after losing in the divisional round the past two seasons.

Sean Payton joined the Denver Broncos, hoping to help Russell Wilson regain his Pro Bowl form and turn the Denver Broncos into winners.

Doug Pederson, who won a Super Bowl in his second season in Philadelphia, will try to guide Jacksonville to make a similar leap after quickly rebuilding Urban Meyer’s mess and leading the Jaguars to a playoff victory.

Then there’s Justin Herbert and the Los Angeles Chargers, Lamar Jackson and the Baltimore Ravens, Tua Tagovailoa and the Miami Dolphins.

And that’s just the AFC contenders.

Fewer teams enter the season with a legitimate chance to win it all, thought it seems there’s always a surprise team. Last year, it was the Philadelphia Eagles. Jalen Hurts and the stacked Eagles are hungry to hoist the Vince Lombardi trophy after wasting a late lead in a 38-35 loss to Mahomes and the Chiefs.

Dak Prescott, Mike McCarthy and the Dallas Cowboys are feeling pressure to lead America’s Team back to glory for the first time in more than 25 years.

The San Francisco 49ers have a dominant defense, versatile offense and quarterback Brock Purdy is healthy again.

Dan Campbell’s Detroit Lions are getting plenty of hype. Perhaps they can overtake the Minnesota Vikings and make a strong playoff push.

Five teams have first-year head coaches, including the Broncos who convinced Payton to end his one-year broadcasting stint and return to the sideline. Payton won a Super Bowl with Drew Brees in New Orleans and knows what it takes to get Wilson and the Broncos back to prominence.

The Carolina Panthers hired former Colts coach Frank Reich to lead a rebuild behind No. 1 overall pick Bryce Young. They’ve got a shot to compete in a weak NFC South.

AP Assistant Coach of the Year DeMeco Ryans took over in Houston. The Texans made bold moves to get QB C.J. Stroud and edge rusher Will Anderson with picks Nos. 2-3 in the draft.

A pair of former Eagles coordinators got the top job with teams that need a new direction. Shane Steichen landed in Indianapolis, which starts the season with rookie QB Anthony Richardson and without disgruntled star running back Jonathan Taylor. Jonathan Gannon went to Arizona, which is looking toward the future and collecting draft capital.

While Rodgers was the biggest name to change teams, a few more accomplished QBs got a fresh start.

Derek Carr traded the silver and black for gold and black in New Orleans. The Saints are the front-runner in a division that didn’t have a winning team in 2022.

Baker Mayfield joins Carr in the NFC South, taking over for Brady in Tampa Bay. He has a chance to resurrect his career with the Buccaneers, who still have playmakers on offense and defense.

Jimmy Garoppolo ended up in Las Vegas, reuniting with Josh McDaniels. All Garoppolo does is win. He’s 44-19, including playoffs. Getting the Raiders over .500 might be his toughest task yet.

The NFL is coming off a record-setting season filled with close games and dramatic finishes. Among the records set in 2022 were most games decided by six or fewer points (122), by seven or fewer points (141) and eight or fewer points (156); most games in which team overcame deficit of 10 or more points to win or tie (52); most games in which teams came back to win after trailing in fourth quarter (85).

The marathon starts Sept. 7 when the Lions visit the Chiefs in the first of 544 NFL games.

Get ready for some football.