Welcome to your worst nightmare.

With five more College Football Playoff rankings remaining, there are ample opportunities for doomsday scenarios in every Power 5 conference. Memphis could be in, and the SEC could be out. Notre Dame could be in and two Power 5 conferences could be out. Before you get too comfortable -- before you lock down your bets that Clemson, Ohio State and Baylor will finish the season undefeated -- remember reality.

This is college football, where Washington State loses to Portland State and Arkansas loses to Toledo. You thought TCU dropping from No. 3 to No. 6 was bad last year? Check out these scenarios ...

Doomed if: The Coastal Division champ wins the ACC title. Doesn't matter who it is -- Duke, North Carolina, Pitt. Take your pick. Any one of those teams would likely put a dagger in the league's playoff hopes because they'd each have at least one loss, and the only truly impressive win would be in the title game. This scenario is the very reason the CFP didn't want automatic qualifiers in the playoff, because a conference champion isn't always one of the best teams in the country. According to ESPN's Football Power Index, Duke's best wins are against Georgia Tech and Virginia Tech, which are a combined 7-11. UNC lost to South Carolina. And Pitt just dropped out of the AP Top 25 after losing to North Carolina.

Don't think Coastal chaos can happen? Then you haven't been paying attention to the ACC, where Miami just beat Duke with eight laterals in one of the worst-officiated games in the sport's history.

Doomed if: It's left out. Could you imagine?! Art Briles and Gary Patterson just might carpool straight to CFP headquarters in Dallas and put up 60 points on Bill Hancock's desk. It's hard to imagine an undefeated Big 12 champ would be left out, but here's why it could: An undefeated LSU, undefeated Clemson, undefeated Big Ten champ and one-loss Notre Dame could make a case for the top four teams in the country -- especially if Notre Dame beats Stanford on Nov. 28, and the Cardinal go on to win the Pac-12.

If that scenario happened, and an undefeated Baylor gets in with nonconference wins against SMU, Lamar and Rice -- three teams that have combined for a 9-15 record -- it would send a message to coaches and athletic directors everywhere to go ahead and schedule down. As long as you're undefeated, you're in. The only thing giving TCU a slight edge over Baylor in the nonconference schedule would be Minnesota -- again -- and the Golden Gophers aren't looking as strong as they did a year ago. Let's face it: After being snubbed last year, any scenario that doesn't have the Big 12 champ in the top four screams doomsday in Dallas.

Doomed if: Michigan wins the Big Ten. It's not anywhere near over in the Big Ten, which still has three undefeated teams and the possibility of a three-way tie in the East Division. If Ohio State beats Michigan State -- hardly a far-fetched result -- and Michigan wins out, then there will be a three-way tie between them, with each having lost to one another. In that scenario, it could come down to which team is ranked highest by the selection committee on Dec. 1. Let's say it's Michigan, and the Wolverines knock off an undefeated Iowa team to win the title: The committee would like the Wolverines. But would it like them enough to put a two-loss Big Ten champ in the top four? Probably not if the other Power 5 conferences have produced an undefeated champ or one with one loss.

Doomed if: Stanford loses to Notre Dame but wins the Pac-12 title. In this scenario, the selection committee would have to choose between a two-loss conference champion (Stanford) and a one-loss team with the head-to-head win. This would be an interesting debate because it would force the committee to reveal what it considers more valuable: a conference title or a head-to-head result.

Stanford's only two losses would be to nonconference opponents Northwestern and Notre Dame. Notre Dame would have beaten the Pac-12 champ, though, and its only loss would have been on the road to what could be the ACC champ in Clemson. It's hard to see the committee ignoring the head-to-head result, especially considering it was the tiebreaker last year when evaluating TCU and Baylor in the final rankings. A one-loss Notre Dame team would trump a two-loss Pac-12 champ.

Doomed if: Ole Miss wins the SEC and Memphis goes undefeated. Maybe this is all it would take to see the CFP expand overnight. The more realistic scenario is that Memphis would garner serious consideration for a playoff spot from the selection committee. The Tigers would have had a win over the SEC champs, not to mention a win over a ranked Houston team and possibly two wins over a ranked Temple team. That résumé could trump a two-loss SEC champ that lost to Memphis.