The College Football Playoff bracket was revealed Sunday afternoon, three weeks before LSU, Ohio State, Clemson and Oklahoma will meet in the semifinals.

The 13-member College Football Playoff selection committee — made up of athletic directors, former coaches, former players and reporters — began ranking the nation's top 25 teams toward the end of the season, and the top four teams in the final rankings advanced to the semifinals. Ohio State, LSU and Clemson were the top three teams in last week's rankings, but No. 4 Georgia dropped back after getting pasted by LSU in Saturday's SEC title game. No. 5 Utah lost to Oregon in the Pac-12 title game, opening the door for Oklahoma. LSU passed Ohio State to earn the top seed.

Three of the four starting quarterbacks in the College Football Playoff are transfers.

No. 1 LSU (13-0)

First playoff appearance. After years of stodginess on offense, the Tigers remade themselves as a dynamo thanks to the combination of quarterback Joe Burrow and passing game coordinator Joe Brady, the 30-year-old wunderkind whom LSU plucked out of NFL obscurity. Burrow set the SEC record for single-season passing yards and tied the record for touchdowns during the regular season, when the Tigers averaged nearly 50 points per game. The party continued on Saturday, when LSU routed Georgia 37-10 in the SEC title game. Defense could be a concern, though, as LSU gave up at least 450 yards and 37 points in a game four times this season.

No. 2 Ohio State (13-0)

Third playoff appearance (champion in 2014-15). The Buckeyes (and the Big Ten) are back in the playoffs for the first time since Ohio State's semifinal appearance in 2016-17. Ohio State became just the second FBS team, along with Florida State in 2013, to start a season with 13 straight double-digit wins. The Buckeyes trailed in the second half for the first time all season in the Big Ten title game, before dominating Wisconsin in the second half. Quarterback Justin Fields threw only one interception during the regular season, and running back J.K. Dobbins was the nation's fourth-leading rusher during the regular season, eclipsing 1,000 yards for the third straight year and averaging 6.6 yards per carry.

No. 3 Clemson (13-0)

Fifth playoff appearance (champion in 2016-17, 2018-19). This is the sixth edition of the playoffs, and the Tigers have been a participant in five of them. Clemson had its doubters after a late-September scare against North Carolina, but it's been simply unstoppable since then, winning its final seven regular-season games by an average of 41.7 points. Then Clemson steamrolled Virginia 62-17 in the ACC title game. Over the Tigers' final five regular-season games, sophomore quarterback Trevor Lawrence completed 76% of his passes with 19 TDs and zero interceptions. Clemson's pass defense, meanwhile, surrendered just six passing touchdowns in the regular season.

No. 4 Oklahoma (12-1)

Fourth playoff appearance (has never won a playoff game). The Sooners return to the playoff for the fourth time in five seasons hoping to finally get over the semifinal hump. Transfer Jalen Hurts adapted well to coach Lincoln Riley's offense, rushing for 1,217 yards and 18 touchdowns while also completing 71.9% of his passes and throwing 31 touchdown passes. Oklahoma's defense is the worst of the four playoff teams, even if it did lead the Big 12 in yards allowed per game one season after finishing dead last. The Sooners allowed 58 plays of at least 20 yards during the regular season, which tied for 78th in the nation. But they allowed just 265 total yards in Saturday's Big 12 title game.