There are 11 undefeated teams left in the FBS -- eight in the Power 5 conferences and three in the American Athletic Conference. Not all undefeated records, though, are created equally. The 13 members of the College Football Playoff Selection Committee don't reveal their first ranking until Oct. 30, but their task then and for six straight weeks afterward is to sort through comparable résumés and determine what separates teams when their records don't.
Sort of like this ...
The following are rankings of the remaining undefeated teams, starting with who has the most realistic chance to reach the CFP semifinals and why.
Win and they're in
1. Alabama Crimson Tide (6-0)
Remaining strength of schedule: No. 27
Toughest remaining game: Nov. 3 at LSU
FPI says: Alabama is favored by at least 80 percent in each of its remaining games.
Playoff predictor says: Alabama could drop any one of its six remaining games and still have at least a 63 percent chance to reach the playoff.
The Tide are as close to a lock as you're going to get in mid-October, as Alabama has looked in a class of its own with quarterback Tua Tagovailoa. His QBR of 98.5 through six games is the highest by any quarterback in the 15 seasons that the metric has been tracked. And here's the most astounding part: He hasn't even taken a snap yet in a fourth quarter. Alabama's only weakness right now is its schedule. The nonconference strength of schedule currently ranks 127th in FBS (but so was Washington's in 2016). Still, Alabama's sheer dominance coupled with the 55-point road win at Ole Miss and the victory over a ranked Texas A&M team should be enough to impress the committee.
Bottom line: The SEC champ is in, and Alabama proved last year it doesn't even need that to reach the semifinals. It would probably take two upsets to derail the Tide.
2. Ohio State Buckeyes (6-0)
Remaining SOS: 34
Toughest remaining game: Nov. 24 vs. Michigan
FPI says: Ohio State has at least a 71 percent chance to win each of its remaining games.
Playoff predictor says: Ohio State could drop any one of the six games remaining on its schedule and still have at least a 67 percent chance to reach the playoff.
The Big Ten champion has been left out of the playoff in each of the past two seasons, but Ohio State already is in a much better position. Instead of suffering a hangover after the Penn State win, Ohio State pulled it together the following week, this time holding off a pesky Indiana team. The Buckeyes still have one of the most impressive résumés because of their road win at Penn State and the neutral site win against TCU. They rank No. 1 in ESPN's Strength of Record metric, which gives the average Top 25 team just a 9 percent chance to go undefeated against the same schedule. Quarterback Dwayne Haskins has 25 touchdowns to just four interceptions. He's a big reason why the Buckeyes are fifth in offensive efficiency this season at 86.1, their best mark since finishing with an efficiency of 87.5 on their way to the title in 2014.
Bottom line: The toughest part of Ohio State's schedule is behind it, save for the regular-season finale against Michigan. The Buckeyes would still have a great shot even as a one-loss Big Ten champ, but it would then depend on how the other Power 5 champs and Notre Dame finish.
3. Notre Dame Fighting Irish (6-0)
Remaining SOS: 64
Toughest remaining game: Nov. 24 at USC
FPI says: Notre Dame has at least a 70 percent chance to win each of its six remaining games and a 38 percent chance to finish undefeated (second-clearest path in an undefeated regular season in FBS, behind Clemson).
Playoff predictor says: If the Irish run the table, they would have a 95.9 percent chance to reach the playoff and a 13.1 percent chance to win it all. If Notre Dame loses to USC, its chances would drop to 59.5 percent.
The Irish have the résumé and are passing the eye test, thanks to the emergence of Ian Book at quarterback. Notre Dame was 70th in FBS in offensive efficiency in its first three games and is 14th since Book became the starter. Coach Brian Kelly also has praised the maturity of the team and its ability to handle the attention that increases with each win.
Bottom line: It's highly unlikely an undefeated Notre Dame would be left out of the top four. If the Irish lose, it opens the door for debate, and they would have to hope that Stanford can rebound in the second half of the season and Michigan stays ranked and in the hunt for the Big Ten title.
4. Clemson Tigers (6-0)
Remaining SOS: 37
Toughest remaining game: Nov. 10 at Boston College
FPI says: Clemson has the best chance to finish 13-0 of any team in the FBS (46.5 percent according to FPI).
Playoff predictor says: If Clemson finishes the regular season undefeated, it has a 91.3 percent chance to make the playoff and a 24.3 percent chance to win it all.
The Tigers have three true road wins (at Texas A&M, at Georgia Tech and at Wake Forest) against teams currently .500 or better, which will impress the committee. So will Clemson's offense, as quarterback Trevor Lawrence completed 20 of 25 passes for 175 yards and three different players ran for at least 125 yards apiece on Saturday at Wake Forest. Clemson also is leading the country in defensive efficiency.
Bottom line: An undefeated ACC champ would be in. The question is whether Clemson can afford to lose a game, because the rest of the ACC isn't as strong as it was a year ago. The answer: Probably, as long as it's not on Oct. 20 against NC State. No loss would damage Clemson's playoff hopes more, because the Wolfpack would then own the Atlantic Division tiebreaker against Clemson and have the only realistic shot in the division to finish either 8-0 or 7-1 (and own the head-to-head tiebreaker over Clemson). If Clemson finishes 11-1 but doesn't reach the ACC title game after losing to NC State, its chance to reach the playoff drops to 37 percent (versus 76 percent if it goes 12-1 after losing to the Wolfpack).
5. Georgia Bulldogs (6-0)
Remaining SOS: 9
Toughest remaining game: Saturday at LSU
FPI says: The Bulldogs are about to enter a four-game stretch that is the sixth toughest in FBS this season. That gives Georgia some wiggle room, since the average Top 25 team would only have a 6 percent chance to sweep those four games and a 7 percent chance to finish 11-1 against Georgia's schedule.
Playoff predictor says: If both Alabama and Georgia are 12-0 entering the SEC championship game, there's a 64 percent chance that both will make the playoff.
Georgia has looked dominant, but it doesn't have any wins against teams that are currently ranked, and it has played one FCS opponent in Austin Peay. Saturday at LSU will be its first chance to make a statement on the national stage. Tennessee (2-3) is the only opponent they've beaten that is under .500, though, and Georgia has two road wins (at South Carolina and Missouri). Georgia ranks second in defensive efficiency and fourth in offensive efficiency. The Bulldogs, along with the Crimson Tide, are the only teams that rank in the top 10 in the FBS in both categories.
Bottom line: We've seen two SEC teams before, and we can see it again.
Dark horses
1. West Virginia Mountaineers (5-0)
Remaining SOS: 3
Toughest remaining game: Nov. 23 vs. Oklahoma
FPI says: West Virginia's final four games are the third-toughest closing stretch in FBS this season (behind Rutgers and Maryland). FPI projects the Mountaineers to lose three of the last four, with the lone win coming at home against TCU.
Playoff predictor says: If West Virginia finishes as a one-loss Big 12 champ, with its lone loss coming to Oklahoma in the regular-season finale, its playoff chances would be 43.5 percent.
The Mountaineers are the Big 12's only undefeated team left after Oklahoma's loss to Texas. They're in good company, as they rank third in ESPN's Game Control metric behind Alabama and Georgia, and they have the best strength of schedule among teams to only play five games so far (5-0 against West Virginia's schedule is almost identical to 6-0 versus Alabama's schedule to date). Their problem is they haven't always looked like a top-four team. West Virginia had four turnovers on Saturday against Kansas, including three interceptions in the red zone.
Bottom line: West Virginia still has to prove it has staying power, but if it can make a run at the Big 12 title and finish as a one-loss champ, it would certainly be considered. The problem for West Virginia (and the entire Big 12) is Notre Dame. The Irish are in a much better position to run the table, and an undefeated record would almost guarantee a top-four finish over a one-loss Big 12 champ. It also would depend on how the other Power 5 champs fare, as well as how Alabama and Georgia finish.
2. NC State Wolfpack (5-0)
Remaining SOS: 67
Toughest remaining game: Oct. 20 at Clemson
FPI says: If NC State can beat Clemson in two weeks, it will be favored the rest of the way, but FPI only gives the Wolfpack a 10.1 percent chance to win. An average Top 25 team would only have a 3 percent chance to go 11-0 against this schedule, which would fit the résumé of past playoff participants.
Playoff predictor says: Even if NC State finishes as an undefeated ACC champ, it still only has a 44 percent chance to make the playoff.
It hurt NC State tremendously that its game against West Virginia was canceled due to Hurricane Florence, because the Wolfpack don't have one Power 5 nonconference win (JMU, Georgia State and Marshall). All 16 past semifinalists have played a regular-season nonconference game against a Power 5 opponent.
Bottom line: Even if NC State shocks Clemson and wins the ACC, it wouldn't be a lock.
Long shots
1. Colorado Buffaloes (5-0)
Remaining SOS: 31
Toughest remaining game: Oct. 20 at Washington
FPI says: The only game Colorado is favored to win is Oct. 27 versus Oregon State. The Buffaloes are an FPI underdog in six of their seven remaining games and have less than an 0.1 percent chance of winning out.
Playoff predictor says: If Colorado is an undefeated Pac-12 champ, it has a 0.0 percent chance of making the top four.
Bottom line: The Buffaloes would need to finish as an undefeated Pac-12 champ, as their nonconference strength of schedule ranks 119th in the FBS, and Washington is currently their only ranked opponent. Even if they do defy the odds and win out, the Buffaloes would need a lot of chaos around them in the rankings to be considered by the committee.
2. UCF Knights (5-0)
Remaining SOS: 77
Toughest remaining game: Saturday at Memphis
FPI says: Even at 12-0, UCF's strength of record would pale in comparison to the previous CFP participants. The average Top 25 team would have a 33 percent chance to go 11-0 against UCF's regular-season schedule, and all past 16 semifinalists have been under 20 percent.
Playoff predictor says: An undefeated UCF champ has a 0.2 percent chance of finishing in the top four.
Bottom line: It's déjà vu. The weak strength of schedule would again keep it out of the playoff. UCF's nonconference schedule is 125th, and the Knights might not face a ranked opponent all season.
3. South Florida Bulls (5-0)
Remaining SOS: 70
Toughest remaining game: Oct. 27 at Houston
FPI says: The Bulls are projected to lose four of their last five games and have a 0.3 percent chance of winning out.
Playoff predictor says: An undefeated USF champ has a zero percent chance to get to the playoff.
Bottom line: South Florida hasn't looked strong enough to win its conference, let alone finish in the top four. The Bulls rank 65th in offensive efficiency (51.3) and 54th in defensive efficiency (58.1).
4. Cincinnati Bearcats (6-0)
Remaining SOS: 80
Toughest remaining game: Nov. 17 at UCF
FPI says: Cincinnati has at least a 60 percent chance to win all of its remaining games, except at UCF (25 percent).
Playoff predictor says: An undefeated Cincinnati has a zero percent chance at the playoff.
Bottom line: It's not going to happen. The Bearcats' strength of record is currently 17th, easily the lowest of the six teams that are currently 6-0.