The first College Football Playoff ranking will be released on Nov. 24, almost exactly one month from now. That's plenty of time for what you think you know to change.

All it takes is one upset -- for one-loss Penn State to redeem itself on Halloween with a home win against Ohio State -- for an entire conference to be thrown into chaos. (Yes, even two games into a season.) If the Nittany Lions instead start the season 0-2, the Big Ten boils down to the Buckeyes vs. the best in the West.

The question is how long each Power 5 conference can hang on to an undefeated team, which is the closest thing to a guarantee when it comes to a CFP semifinal spot. Alabama and Clemson have been the best, most consistent contenders, but Ohio State can prove the same with more opportunities. Undefeated Notre Dame saw its offense wake up in a 45-3 road win at Pitt, and the Big 12 still has an undefeated team in Oklahoma State.

The Pac-12 hasn't even joined the party yet.

To be clear, one-loss teams have not been eliminated from the playoff conversation -- but as long as there are undefeated teams remaining, it's far more difficult for a contender such as Georgia to make a top-four case.

Here's a look at the undefeated playoff contenders, ranked in order of who has the best shot to finish the regular season undefeated:

1. Clemson

Quick playoff take: The Tigers rank in the top five in both offensive and defensive efficiency, which is what could separate them from Alabama in the eyes of the committee. The Tigers have a top-15 win against Miami, and though it was fair to question Dabo Swinney about mistakes in Saturday's 47-21 win over Syracuse, that game isn't going to change Clemson's playoff position (though you can certainly debate who's No. 1). Three of Clemson's final five games are on the road, but ESPN's Football Power Index gives the Tigers at least an 82% chance to win all of them.

Toughest remaining test: Nov. 7 at Notre Dame. If the Irish continue to build on Saturday's offensive success at Pitt, this game could be close. The bigger question is if Notre Dame's defense -- which is the reason the Irish beat Louisville 12-7 -- can slow down Trevor Lawrence & Co.

2. Alabama

Quick playoff take: The Tide defeated Tennessee but lost star receiver Jaylen Waddle to a season-ending ankle injury. Although Bama's offense is still loaded, that's a devastating blow, as Waddle has a great ability to make big plays and was a threat to score off kick returns. His absence shouldn't derail the Tide's playoff hopes, though. Alabama's most difficult stretch of the season is behind it, as the Tide might not face another ranked opponent in the regular season. ESPN's FPI gives Bama at least an 82% chance to win each of its remaining games. Alabama's defense has also shown steady improvement each of the past two weeks after raising concerns on Oct. 10 with a 63-48 win at Ole Miss.

Toughest remaining test: Nov. 14 at LSU. The only reason that's slightly more difficult than the Nov. 28 Iron Bowl is because it's a road trip, and Alabama gets Auburn at home. Even without Waddle, Alabama's offense should have the edge against what have been mediocre defenses from both LSU and Auburn.

3. Ohio State

Quick playoff take: One lopsided win against an unranked Nebraska team isn't enough to fairly compare the Buckeyes to the likes of Alabama and Clemson, but yes, Justin Fields is that good, and Ohio State's eight-game schedule is extremely winnable. Fields threw one incomplete pass -- one! -- for a 95.2% completion rate. Penn State and Michigan will probably be the Buckeyes' only ranked opponents before the Big Ten title game. There were times when Ohio State's offensive line was pushed around by Nebraska's defensive front. How much more can the Buckeyes get out of their ground game without putting Fields at risk?

Toughest remaining test: Saturday at Penn State. Will the Nittany Lions be emotionally spent after an overtime loss at Indiana? Or will they be determined to get back into the playoff conversation? If Ohio State loses, that head-to-head result could keep this team out of the Big Ten title game.

4. Wisconsin

Quick playoff take: We've seen this movie before. Wisconsin looks good all season, wins the West and then loses to Ohio State in the Big Ten title game. Can this season be different? Maybe, with quarterback Graham Mertz leading the offense. You thought Fields was good? Well, Mertz did the same exact thing, completing 20 of 21 passes on Friday in a 45-7 win over Illinois -- and he had the better day, with five touchdowns. ESPN's FPI favors the Badgers to win every game this year by at least 84%. If both Ohio State and Wisconsin enter the Big Ten championship game undefeated, it's always possible the selection committee would take both teams in its top four -- but that would depend on how the other Power 5 races play out.

Toughest remaining test: Nov. 14 at Michigan. The Wolverines looked good in their opener against No. 21 Minnesota, and this game is in Ann Arbor.

5. Notre Dame

Quick playoff take: In a shocking concession of honesty, coach Brian Kelly bucked the coach speak of "one game at a time" and said, "We are looking ahead a little bit." The Irish know they face Clemson in two weeks -- following what should be an easy win Saturday at Georgia Tech -- and Kelly challenged his team to start playing up to that level now. "We're not interested in just winning football games," he said. "We're interested in being a championship football team." Notre Dame looked capable of that at Pitt, where the Irish played a complete game in all three phases. Remember, Notre Dame is part of the ACC this season, so even if the Irish lose at home to Clemson during the regular season, they could get a second chance at the Tigers in the ACC title game. An upset in that game would make for a very interesting debate in the committee meeting room.

Toughest remaining test: Nov. 7 vs. Clemson. This isn't the only game that can derail a perfect season for Notre Dame. Don't forget about the Nov. 27 Friday night trip to North Carolina, which has improved drastically in the second season under Mack Brown.

6. Oklahoma State

Quick playoff take: Saturday's win against a ranked, relentless Iowa State team was a reminder that the Big 12 isn't out of the playoff conversation yet. According to the Allstate Playoff Predictor, Oklahoma State has a 41% chance to win the Big 12. If the Cowboys can do that with one loss or zero, they would be considered for a top-four spot, but the minute they lose, their chances will significantly decrease. The strength of the conference could be an issue when comparing a one-loss Oklahoma State champ to the ACC, SEC and Big Ten champions. Oklahoma State's defense, which has allowed just 51 points so far, has been one of the reasons for its success.

Toughest remaining test: Nov. 21 at Oklahoma. This is the only game on the Cowboys' schedule in which ESPN's FPI gives them less than a 50% chance to win (48%).

7. Michigan

Quick playoff take: Quarterback Joe Milton did exactly what Michigan needed him to: manage the offense without turning it over. It wasn't flashy, and the Wolverines beat No. 21 Minnesota with their running game and defense. They can continue to win that way -- but probably not at the highest level. Of the Big Ten teams listed here, Michigan arguably has the most difficult path, with games against Indiana, Wisconsin, Penn State and Ohio State. The possibility of Michigan getting through all of that unscathed doesn't seem realistic, but with only one game played, there is plenty of time for the Wolverines to improve and prove otherwise.

Toughest remaining test: Dec. 12 at Ohio State. Good luck. ESPN's FPI gives Michigan an 8.3% chance to win that one.

GROUP OF 5 UNBEATENS

For a team outside of the Power 5 to be considered for a spot in the CFP, it almost assuredly has to finish undefeated. And beat ranked opponents. And get some major chaos in the Power 5 races. It's not impossible, though. The following teams are ranked in order of their likelihood to stay undefeated, and though Liberty is last, it also has the best opportunities to impress the committee:

1. BYU: The Cougars last started 6-0 in 2008, and they entered Saturday's game against Texas State with a 48% chance to win out this season, according to ESPN's FPI. Only Clemson (59%) has better odds of finishing the regular season undefeated. Quarterback Zach Wilson has been outstanding and helped legitimize BYU as a contender, but with no Power 5 opponents or opportunities against ranked opponents, it will be difficult to convince the committee that the Cougars deserve a spot over a Power 5 contender with a better résumé -- even one with a loss. BYU's toughest remaining game is Nov. 6, a Friday night at Boise State, but ESPN's FPI gives BYU a better than 50% chance to win each of its remaining games.

2. Marshall: Its best win was Sept. 19 against then-No. 23 Appalachian State, and there probably won't be another ranked opponent in the regular season. Although that increases the Herd's chances of finishing undefeated, it won't do much to impress the selection committee -- a tough lesson Marshall learned after its 11-0 start in the CFP's inaugural season in 2014.

3. Coastal Carolina: The Chanticleers have wins at Kansas and at then-No. 21 Louisiana and are No. 7 in offensive efficiency. They're a good team, but ESPN's FPI gives Coastal Carolina only a 36.7% chance to beat Appalachian State on Nov. 21.

4. Cincinnati: With the win at SMU, the Bearcats increased their chances of reaching the AAC championship game from 21% to 31%, according to ESPN's FPI. Cincinnati has been a strong defensive team, and that was on display Saturday in the win at SMU, which was the Bearcats' most impressive to date. With remaining games against Memphis, Houston, at UCF and at Tulsa, it isn't going to be easy to finish undefeated.

5. Liberty: The Flames are last on the list because it's highly unlikely that they will finish the season undefeated, but if Hugh Freeze can make that miracle happen, Liberty might have the best résumé of any non-Power 5 team in the playoff era. The Flames would have defeated Syracuse, won in Blacksburg against No. 19 Virginia Tech, won on the road against No. 23 NC State and won on the road at No. 25 Coastal Carolina.