(CNN) The four-team field for the College Football Playoff will be revealed Sunday, and depending on this weekend's conference championship games the selection committee's task will either be straightforward or tricky.

Heading into Week 15, the top seven teams in the College Football Playoff ranking are still in contention. The field looks like this:

Take a glance at the #CFBPlayoff top four teams heading into conference championship and Selection Weekend. 1️⃣. Ohio State // @OhioStateFB 2️⃣. LSU // @LSUfootball 3️⃣. Clemson // @ClemsonFB 4️⃣. Georgia // @GeorgiaFootball Who's in? Tune in on Sunday to find out. 👀 🏈🏆 pic.twitter.com/v5ujqbTntE

The schedule of games with playoff implications this weekend:

ESPN will air the College Football Playoff Selection Show from noon to 4 p.m. ET on Sunday.

"Obviously this weekend's conference championship games will be crucial to determining the final rankings," committee chair and Oregon athletic director Rob Mullens told reporters Tuesday. "I, along with my fellow committee members, look forward to returning to Dallas in just a few days to watch those games and complete our work."

ICYMI, Rob Mullens, chair of the #CFBPlayoff selection committee, chatted with @ESPN's @ReceDavis after the reveal of the penultimate CFP Top 25 on Tuesday, December 3.



Who's in? 🏈🏆 pic.twitter.com/QKG1PQq9wW — College Football Playoff (@CFBPlayoff) December 4, 2019

In the Big Ten championship game, Ohio State is a solid favorite against Wisconsin (10-2), as the Buckeyes already beat the Badgers 38-7 in the regular season. Clemson, the defending national champion, is heavily favored against Virginia (9-3) in the ACC title game.

But the key piece to the playoff picture is Georgia. If the Bulldogs beat LSU in the SEC championship game, this could be relatively simple for the committee. Win, and Georgia will likely remain in with Ohio State, LSU and Clemson (though the seedings could shuffle).

Things could also get easier for the committee if Oregon (10-2) upsets Utah in the Pac-12 title game. A loss would eliminate the Utes from playoff consideration.

If LSU defeats Georgia, things get more interesting, opening up possibilities for Utah, Baylor or Oklahoma to snag the fourth spot. Baylor and Oklahoma play each other in the Big 12 championship game. It'll be a rematch from earlier this season, when the Sooners overcame a 28-3 deficit to beat Baylor 34-31 in Waco, Texas.

One team that won't factor in this year is Alabama (10-2). For the first time since the College Football Playoff began five years ago, the Crimson Tide will be absent, having lost this past week to Auburn and dropping to 12th in the ranking.

The College Football Playoff has been around since the 2014 season, replacing the BCS . The playoff teams are selected by a 13-person committee, which ranks teams based on performance, strength of schedule, conference championships won, head-to-head results and comparing results against common opponents. The winner of the playoff determines the national champion at the top level of college football.

The College Football Playoff semifinals will be held December 28 at the Chick-fil-A Peach Bowl at Mercedes-Benz Stadium in Atlanta and the PlayStation Fiesta Bowl at State Farm Stadium in Glendale, Arizona. The national championship game will be January 13 at the Mercedes-Benz Superdome in New Orleans.