We're four weeks into the college football season, and it's already been filled with crazy upsets, fantastic finishes, and moments some fans will be talking about for years to come. Some teams have started to emerge from the pack, but with conference play just getting started there's still a long way to go. It's almost inevitable that some of these teams will finish undefeated, as at least one team has entered postseason play without a loss since 2008. Here are the teams that have the best shot at keeping that streak alive.
4. Oklahoma Sooners
Oklahoma still has to end the season with three ranked opponents in their final four games, but after defeating Ohio State in Columbus looks to be ready for any challenge. The Sooners haven't lost since the Buckeyes beat them in Norman last year, and senior quarterback Baker Mayfield looks like he's on a mission.
3. Clemson Tigers
Just four weeks into the season, it looks like we're headed for Alabama-Clemson part 3. The Tigers already crushed Louisville on the road, and Florida State, who looked to be their toughest opponent, lost quarterback Deondre Francois for the season in Week 1. Clemson's biggest remaining challenge may be this week when they take on No. 12 Virginia Tech.
2. Alabama Crimson Tide
The Crimson Tide are the class of the SEC once again, and there doesn't appear to many teams left in the conference that will provide much of a challenge. Alabama still has to be careful in road games against Mississippi State and arch-rival Auburn, but don't be surprised if the Tide head into the College Football Playoffs without a loss.
1. San Diego State Aztecs
There's always one Group of 5 team that crashes the party, and right now, San Diego State looks to be that team. The Aztecs defeated then-No. 19 Stanford on Sept. 16, and are heavy favorites in the rest of their games, according to ESPN's Football Power Index. According to the FPI, their toughest remaining game is Oct. 14 against Boise State, when they only have a 72.6 percent chance to win.