Will the transfer portal be the best thing to happen to the College Football Playoff? The quarterback carousel has opened a door to a series of unintended consequences, including this fun one: the possibility of Heisman hopeful quarterbacks facing their former teams on the sport's biggest stage.

Jalen vs. Tua, anyone?

We thought so.

Entering Week 3, the race for the top four spots is still in its infancy, but based on what we've seen so far, it's easy to get excited about some potential semifinal storylines. Get ready, because they're actually possible. Well, most of them (sorry, Group of 5).

Here's a ranking of College Football Playoff semifinal matchups that would make for a wildly entertaining postseason, and the chances of both teams actually reaching the semifinals according to the Allstate Playoff Predictor.

1. Oklahoma vs. Alabama
The main event: Jalen Hurts vs. Tua Tagovailoa

Why we want it: Tagovailoa beat Hurts once already, when he won the starting job at Alabama. Hurts was 26-2 with two championship game appearances in his two seasons as the Tide's starter. Then the Tua Takeover began. After a year as a backup, Hurts headed to Oklahoma, where he could potentially become the Sooners' next Heisman-winning QB.

Why it could actually happen: Because it already has? Alabama beat OU 45-34 in last year's playoff, and neither team has shown any signs of taking a step back. Hurts hasn't missed a beat stepping in for Kyler Murray, but if he's going to get a chance to beat his former team, it will be because the defense looks legit under first-year coordinator Alex Grinch. So far it has. ESPN's Football Power Index favors both OU and Alabama to win every remaining game.

Chance both make the CFP: 15.5%

2. Ohio State vs. Georgia
The main event: Justin Fields vs. Jacob Fromm

Why we want it: Fields signed with the Bulldogs as the No. 1 recruit in the 2018 ESPN 300, but with Fromm entrenched as Georgia's starter, and allegations that a former Georgia baseball player shouted racist remarks at him during a football game, Fields moved on. He was granted immediate eligibility by the NCAA and is showing why he was such a highly touted prospect. Fromm, who is Mel Kiper Jr.'s No. 25 2020 draft prospect, awaits his first big test (Week 4 against Notre Dame).

Why it could actually happen: The selection committee remembers the Big Ten has a champion. The league's winner has been snubbed each of the past three seasons (in 2016, Ohio State made it over champ Penn State). If the Pac-12 continues to beat itself up, though, and Notre Dame falters at some point, it would be tough for the committee to leave the Buckeyes out. ESPN's FPI projects Ohio State to win each of its remaining games, but with a backloaded schedule that currently includes five ranked opponents, it's not going to be easy. Georgia can relate. The Bulldogs face Notre Dame, Auburn and Texas A&M. Oh, and the SEC championship game. Good luck.

Chance both make the CFP: 4.7%

3. LSU vs. Ohio State
The main event: Joe Burrow vs. Justin Fields

Why we want it: Joe Burrow put it bluntly: "I didn't come here to sit on the bench for four years," he said in May 2018. So Burrow left Ohio State, transferred to LSU, won a wide-open competition -- and is suddenly in the Heisman race and has the NFL taking notice.

Why it could actually happen: Because LSU finally has a quarterback. The Tigers' offense had been stuck in a time warp for years. Now it's in fast-forward and has seemingly caught up to the rest of the sport, spreading the field, flinging the ball to speedy receivers. The only game FPI doesn't favor the Tigers to win is Nov. 9 at Alabama (surprise), but it might not matter. If the Tide wins the SEC, and that's LSU's only loss, it's possible they both still make the playoff.

Chance both make the CFP: 8.9%

4. Boise State vs. Oklahoma
The main event: Oklahoma vs. hook-and-ladders and on-field proposals

Why we want it: The year? 2007. The bowl? Fiesta. The No. 9 Broncos were undefeated and stayed that way after an instant classic 43-42 overtime upset of No. 7 Oklahoma. Remember? Hook-and-ladder? Fourth-and-18? Yeah, let's do that again.

Why it could actually happen: The playoff magically expands by December. OK, OK, this game probably isn't going to happen with the playoff at four teams. But let's play it out, anyway. The toughest remaining game on the Broncos' schedule is Oct. 19 at BYU. According to ESPN's FPI, Boise State has at 6.4% chance of going undefeated. (Fellow Group of 5 squad UCF is at 20%.). Say what you want about strength of schedule -- or the fact that this game almost assuredly won't happen -- but don't deny the classics underdogs can deliver.

Chance both make the CFP: 0.1%

5. Alabama vs. Michigan
The main event: Nick Saban vs. Jim Harbaugh

Why we want it: These two riveting characters have never faced each other in college. Saban is 6-1 against the Big Ten during his tenure at Alabama. Harbaugh is 2-1 against the SEC while at Michigan, but he did win his quarterback, transfer Shea Patterson, from Ole Miss.

Why it could actually happen: Harbaugh finally beats Ohio State to win the Big Ten, improving to 1-4 against the Buckeyes. It's not hard to imagine this matchup in the 1 vs. 4 scenario, but the onus is on Michigan, which faces Wisconsin on the road in a crossover game, and also plays Notre Dame again this year. If the Wolverines can finish as a one-loss Big Ten champ, the committee wouldn't dare leave them out, would it? Oh, wait ...

Chance both make the CFP: 1.6%

6. Alabama vs. Georgia
The main event: Georgia vs. recent history

Why we want it: It was 2017, and the chants of S-E-C! S-E-C! echoed from Atlanta to ... Atlanta. The league made CFP history when it became the first to have two teams finish in the top four, with Georgia, the SEC champ, at No. 3, and Alabama, which didn't win the West that year (Auburn did), at No. 4. Saban beat another former assistant, Kirby Smart, 26-23 in overtime to win the national title.

Why it could actually happen: Because it's the SEC. Last year, Georgia didn't win the SEC, finished with two losses, and was still seriously considered by some committee members. It's certainly possible the top four looks like this: 1. Clemson, 2. Alabama, 3. Georgia, 4. Pick your Power 5 champ. The toughest remaining game on the Bulldogs' schedule is Nov. 16 at Auburn, but the league has clout, so it wouldn't be surprising to see them both in, regardless of whether they've just played in the SEC title game.

Chance both make the CFP: 20%

7. Alabama vs. Clemson
The main event: The Tide and Tigers vs. Inevitability

Why we want it: Really? You need this? They've met four straight times in the playoff, and the series is now even after Clemson crushed Alabama last year to win the national title. So clearly, we need a tiebreaker.

Why it could actually happen: See above. Until proven otherwise, they're the teams to beat. Clemson's Week 2 win over Texas A&M set the Tigers on the path back to the playoff, as it was arguably the most difficult game on their schedule. If there's one team that seems like a lock right now, it's Clemson, and that's because nobody else in the ACC has looked like a spoiler. Syracuse has been a tricky opponent in the past for Clemson, but after being dismantled by Maryland, there's no sense of an upset brewing. Of course, that's why they call it an upset.

Chance both make the CFP: 59.4%