Ten takeaways from a wild, playoff-altering weekend in college football:

1. Two weeks into the College Football Playoff selection committee rankings, everything has been thrown into the shredder.

Everything but one thing. The surest thing. The Alabama thing.

But even that was in doubt until the last snap on a shocking day that underscored the perils of playing good competition on the road. Top-ranked Georgia was blown out at No. 10 Auburn, third-ranked Notre Dame was blown out at No. 7 Miami, sixth-ranked TCU was blown out at No. 5 Oklahoma — and the lordly Crimson Tide were pushed to the brink at No. 16 Mississippi State.

Alabama was down a touchdown in the fourth quarter, the first time it has trailed in the fourth this season, and the Tide responded with grit and poise. Clutch quarterback Jalen Hurts led three long drives in the final 15 minutes, one resulting in a missed field goal but two ending in touchdowns — the winning score coming with just 25 seconds on the clock. Then they withstood a couple of throws into the end zone at the end to wobble out of Starkville still undefeated.

Alabama assuredly now will rise to No. 1 in the new CFP rankings, but the Tide’s company in the top four will change dramatically. Georgia and Notre Dame will drop out after being completely overwhelmed in big-game settings. Neither had experienced a lick of adversity since they played each other Sept. 9, and when it arrived in large quantities Saturday they both folded.

My top four at the moment: Alabama, Miami, Oklahoma, Clemson. Next: Wisconsin, Auburn, Georgia, Notre Dame, TCU, Ohio State, USC.

It’s a tough call ranking 2 through 5, then a clear separation before a tightly bunched 6 through 11.

2. From a conference standpoint, the big winners Saturday were the ACC and Big Ten. The former should have 40 percent of the top five when the new rankings come out Tuesday, and the latter should see its undefeated Wisconsin Badgers move either into the bracket or just outside it, with at least one guaranteed loser ahead of them.

Clemson and Miami will meet in the ACC title game. If both get through the next two weeks without a loss — the Tigers play Citadel and South Carolina, the Hurricanes play Virginia and Pittsburgh — the winner should be a cinch playoff team. The loser might even be in contention as well — especially if it is Miami at 11-1. The Hurricanes and their Turnover Chains are the big two-week mover, coupling the demolition of Notre Dame with an 18-point win over Virginia Tech the week before.

As for Wisconsin: If everyone held serve in front of the Badgers, there was a chance they could be roadblocked to the playoff — even if they go 13-0, thanks to a putrid schedule. Now, that sort of snub is less likely thanks to the carnage in front of them in the rankings. Georgia losing big is a boost to Bucky.

3. Georgia will have to buck what little College Football Playoff history there is to make the bracket.

In the first three years of the four-team playoff format, nobody has made the field with a loss of more than 14 points. The Bulldogs just got whipped by 23, and needed a late touchdown to make it look that close. It was that bad for the erstwhile No. 1 team Saturday, which made one forehead-slapping mistake after another in Jordan-Hare Stadium.

Three one-loss teams have made the bracket every year, along with one undefeated team. The average margin of defeat for the nine one-loss teams was 6.4 points. So we might be about to find out what the penalty for a blowout loss is.

Of course, if Georgia beats undefeated Alabama in the SEC championship game that would probably go a long way toward erasing the margin of defeat against Auburn.

4. Was today wild enough to enliven the playoff hopes of two-loss teams? One of them for sure, and maybe more.

Auburn could well control its own destiny. The 8-2 Tigers got the first of the three huge wins they would need by crushing Georgia, and would have to follow that up with an Iron Bowl victory and a second win over Georgia in the SEC championship game. Given Alabama’s defensive injuries and Auburn’s 10-game home winning streak, that looks like a very competitive matchup Nov. 25.

The Tigers’ two defeats came by a total of 11 points on the road against Clemson and LSU, losses that have aged well. They’re better losses than the other two-loss teams would bring to the table, Ohio State and USC. The Buckeyes lost at home by 15 to Oklahoma and by 31 to Iowa; the Trojans lost by three to Washington State and 35 to Notre Dame.

Ohio State at least could add a couple more quality wins, at Michigan and theoretically over unbeaten Wisconsin in the Big Ten title game. (Playing miserable Illinois on Nov. 18 will not help.) But the Buckeyes still would need help. USC doesn’t have comparable quality-win opportunities remaining (UCLA and the Pac-12 title game).

5. How hard is life on the road right now? Very.

Four Top 10 teams lost on the road this weekend, three of them by lopsided margins. For the entire Top 25, ranked teams were 4-8 on the road. Last week, Ohio State and Penn State both saw their playoff hopes all but disappear in road upsets. Come November, winning away from home is proving extremely difficult.

6. Dan Mullen is a very good coach. He has a very good team that played very well Saturday night. But he and defensive coordinator Todd Grantham will have to live with some decisions that didn’t work out well in that agonizing loss to Alabama.

Twice, Mississippi State had fourth-and-short in Alabama territory — once in the first quarter and once in the fourth. Both times, Mullen opted to punt. The first time was the opening possession of the game and the Bulldogs faced fourth-and-2 at the Tide 36 — State took a delay of game and kicked the ball away. The last time was a fourth-and-3 from the Tide 42 with seven minutes left in a tie game.

In a vacuum, both decisions were defensible. But in the big picture of trying to take down the king of the conference, they could be second-guessed. Fortune favors the bold, the saying goes, and Mullen was anything but bold in making those decisions.

Grantham, meanwhile, erred to the other extreme — he was far too bold with his blitz calls on Alabama’s winning touchdown drive. Specifically: on third-and-15 from the Alabama 43 with 31 seconds left, Grantham blitzed and Hurts burned him with a 31-yard completion to Calvin Ridley.

But that at least is who Grantham is and has been — he goes after the quarterback on third downs, even if it means putting his defensive backs in single coverage that can result in big plays. Georgia fans coined the term, “Third and Grantham” years ago because of aggravation from surrendering first downs in those situations. Grantham has done great work with the Mississippi State defense this year — but his unit couldn’t get the stop it absolutely had to have to shock the Tide.

7. Baker Mayfield is close to being in the same position Lamar Jackson enjoyed at this point last season — a Heisman Trophy lock.

Not even closing the season with consecutive upset losses could dislodge Jackson last year, and it’s possible that the same is true right now for Mayfield. He was brilliant yet again Saturday, riddling TCU for 333 passing yards and three touchdowns and running for 50 more yards. Mayfield threw for 299 in the first half alone as the Sooners built an insurmountable lead, and coach Lincoln Riley put his offense in game-management mode thereafter.

Mayfield entered the game on pace for an NCAA record in single-season pass efficiency with a 201.6 rating — and then it went up. It will be hard to deny the two-time Heisman finalist the award this time around, not only because of his own play but the lack of compelling challengers.

Stanford running back Bryce Love is the strongest competition, leading the nation in rushing at 180 yards per game and leading all running backs (with more than 100 carries) in yards per carry at 8.96. But his production has slowed after an injured ankle, and the three-loss Cardinal continue to play many of their games in late-night obscurity. (Arizona quarterback Khalil Tate also is running wild after dark, with few people noticing.)

Penn State’s offensive line issues have hurt Saquon Barkley’s numbers. Jackson is having an even better season statistically than he did last year, but Louisville’s defense has sabotaged him in a 6-4 season. Wisconsin freshman running back Johnathan Taylor again made the offense go, piling up 157 yards on 29 carries, but his production doesn’t match Love’s.

All signs point to Mayfield being named Oklahoma’s sixth Heisman winner a month from now.

8. Tanking teams tanked even harder Saturday, deepening their cycle of despair. The specific culprits: Nebraska, Florida, Tennessee.

The Cornhuskers gave up 54 points and 514 yards to a mediocre Minnesota team, a pitiful performance that left them 4-6 with games remaining against Penn State and Iowa. The Bob Diaco defensive coordinator hire has been an utter bust in Lincoln.

The Gators at least reached the 20-point plateau for the first time since September, but 20 was all in an eight-point loss to South Carolina. It was Florida’s fifth straight loss, and its 3-6 mark is the worst through nine games since 1979.

The Volunteers were the latest team gutted by the improbable late-season Missouri buzzsaw, losing 50-17 in Columbia and falling to 4-6 with what could be two heavily fan-boycotted home games remaining. At 0-6, Tennessee could have its first winless SEC season ever — its last winless conference record came in 1924 as a member of the Southern Conference.

One coaching change already has occurred, in Gainesville. The other two are inevitable. Proud programs in complete disarray.

9. Is Dino Babers the next Kevin Sumlin? The king of the late-season collapse?

Syracuse lost its third straight game Saturday, giving up an ungodly 64 points to Wake Forest. That leaves the Orange (4-6) needing to win at Louisville and at home against Boston College to earn their first bowl bid since 2013.

Last year Syracuse closed with four straight losses, bottoming out by giving up 76 points in regulation to Pittsburgh. Babers is a talented offensive coach who picked up his first signature win at the school in October by upsetting Clemson, but he needs to finish seasons better.

10. As good as Wisconsin has been, quarterback Alex Hornibrook’s interception issues are a major concern down the stretch.

Hornibrook threw three picks against Iowa on Saturday, keeping the Hawkeyes in the game longer than they should have been. The sophomore has thrown at least one interception in the last seven games (11 total in that stretch) — and it’s not like he’s chucking it 40 times a game. Thus far 4.8 percent of his passes have gone to the wrong team.

Saturday opponent Michigan theoretically should be able to slow down running back Taylor and make Hornibook pass, which should cause Wisconsin fans some anxiety. But it could be that the Badgers’ defense is good enough to wallpaper over whatever errors Hornibrook makes.

More college football coverage from Yahoo Sports:
• No. 8 Wisconsin clinches Big Ten West title
• No. 10 Auburn ruins No. 1 Georgia’s undefeated season
• Penn State players help coach propose after win
• The Florida Gators’ latest on-field disaster
• No. 13 Ohio State scores blowout win over No. 12 Michigan State