College football fans are rarely more optimistic than the moment their favorite team is readying to start a new quarterback.

This transition is simply a part of the game. And in 2021, that means Clemson replacing Trevor Lawrence and Ohio State moving on from Justin Fields. National champion Alabama and Pac-12 winner Oregon will have new quarterbacks, along with a handful of other programs that enter the fall as Top 25 teams.

The teams highlighted are based on Bleacher Report's preseason Top 25 and listed in ascending order.

While the choices are ultimately subjective, the decisions factor in previous experience and the most current information.

1 More to Know: QB Competition at Northwestern

Of the nine programs mentioned, Northwestern is the only place where a winner isn't basically settled.

Last season, Indiana transfer Peyton Ramsey led the Wildcats to the Big Ten Championship Game. They're hoping for similar impact from Andrew Marty or another transfer QB—whether it's Hunter Johnson (Clemson) or Ryan Hilinski (South Carolina).

Johnson arrived in Evanston two years ago, but he started five games and averaged just 4.0 yards per attempt. Although the offense had a terrible year overall in 2019, Johnson didn't impress. Perhaps a year-plus out of the spotlight is what he needed.

Hilinski, who transferred to Northwestern this offseason, guided South Carolina in 2019 after replacing the injured Jake Bentley. He threw for 2,357 yards and 11 touchdowns to five interceptions but managed only 5.8 yards per attempt. Then, in 2020, Collin Hill beat out Hilinski for the starting job.

The long story short? Throw in Marty's scattered experience as a backup, and this competition has a long road ahead.

Emory Jones, Florida

Considered a top-100 prospect in the 2018 class, Emory Jones has long been viewed as the future of Florida football.

Jones is very much a dual-threat quarterback and has showed that ability in scattered snaps. In the last three seasons, he's rushed for 514 yards and six touchdowns.

Plus, he's 55-of-86 passing for 613 yards and seven scores. Optimism is already high because of that efficiency, and Florida coach Dan Mullen has a strong reputation for developing quarterbacks. Jones should be among the SEC's top QBs.

Florida lost a ton of receiving production, but Jacob Copeland and Justin Shorter highlight the returning pass-catchers.

Casey Thompson, Texas

Sam Ehlinger put together a strong college career, but an unimaginative offense in the last couple of years stung. Texas is hoping new coach Steve Sarkisian injects more life into the scoring attack, which will likely be under Casey Thompson's direction.

Thompson only handled garbage-time snaps until Ehlinger exited the 2020 Alamo Bowl with a shoulder injury.

And suddenly, the future wasn't so scary.

Thompson finished the game 8-of-10 for 170 yards and four touchdowns, adding 24 rushing yards on three non-sack attempts. He made an excellent impression heading into an offseason of transition where Texas fired Tom Herman and hired Sarkisian.

Right now, Thompson is battling Hudson Card for the starting job. But that competition should end in mid-August.

Jack Coan, Notre Dame

Formerly the starter at Wisconsin, Jack Coan transferred to Notre Dame this offseason. Coan missed the 2020 season with a foot injury, and Graham Mertz took control of the first-string spot.

Coan landed a program where he's basically the only experienced QB.

Notre Dame returns Drew Pyne and Brendon Clark, but they've combined for seven career pass attempts. While the Irish brought in top 4-star Tyler Buchner, California didn't have a high school season in 2020. Expecting him to start the opener is mostly wishful thinking—though a November start is plausible if Notre Dame is no longer in College Football Playoff contention.

To this point, Coan has been a conservative, pass-first quarterback. He posted a 69.6 completion rate with 8.0 yards per attempt and 18 touchdowns to five interceptions as Wisconsin's starter in 2019.

If he's more of a playmaker—especially given the concerns at receiver—Notre Dame may have CFP upside. At worst, though, Coan is a steady option for a Top 25 team.

Anthony Brown, Oregon

Oregon back-doored a second straight Pac-12 title last year, capitalizing on a spot in the championship game after coronavirus issues forced Washington to back out. Then, in the offseason, quarterback Tyler Shough left for Texas Tech.

Shough's decision didn't come as a huge surprise because Anthony Brown carved out a role late in 2020. And here in mid-June, it doesn't seem likely he'll be a backup to begin 2021.

Similar to Coan at Notre Dame, there are legitimate questions about Brown's upside. Can he lead a legitimate national title threat? Brown's past at Boston College suggests he's a respectable starter, but not an elite-tier quarterback.

Relative to the Pac-12, however, Brown can provide defensively driven Oregon needs to chase a third straight league title.

Haynes King, Texas A&M

Whichever player wins the competition at Texas A&M must be ready for a heavy burden of expectations.

Last season, the Aggies narrowly missed the College Football Playoff. In 2021, they return an overwhelming majority of their top tacklers. So, if the defense plays up to its potential, Texas A&M can push Alabama for the SEC West crown.

But that Crimson Tide-sized obstacle is a massive one. And it ultimately comes down to the offense.

Haynes King and Zach Calzada are the leading candidates ahead of freshman Eli Stowers. Calzada served as the backup in 2019, but King—who was labeled a dual-threat quarterback in high school—overtook him as a true freshman last season. That development is reason to consider King the favorite.

Since he has four career pass attempts, though, King is far from proven. This competition could extend into the season.

C.J. Stroud, Ohio State

Like his 2020 classmate King, C.J. Stroud heads into the 2021 campaign with very little experience. He appeared in a couple of games last season but threw zero passes and ran the ball once.

Granted, it was a 48-yard touchdown.

Stroud is an exciting talent who—as you can imagine, considering his one excellent carry—is a dual-threat quarterback. Between his recruiting billing, support of teammates and perceived lead in the spring, Stroud is the definite favorite over Jack Miller and Kyle McCord to replace All-American QB Justin Fields.

And on an offense with Chris Olave and Garrett Wilson—two of the nation's top-three receivers—Stroud has major upside in 2021.

D.J. Uiagalelei, Clemson

If anyone at Clemson claims there is a quarterback competition, do not believe them. This is D.J. Uiagalelei's team.

Trevor Lawrence missed two games in 2020 because of a positive coronavirus test. In his place, the 5-star freshman accounted for 808 yards and six touchdowns. He led a comeback win over Boston College and only lost to No. 4 Notre Dame in double overtime.

Not bad for someone who expected to watch from the sideline.

Uiagalelei is a pass-first quarterback but is plenty mobile, especially when a play breaks down. He may also benefit from the return of Justyn Ross, a two-time 900-yard receiver who is waiting to be cleared after a procedure on his spine.

Factor in a potentially elite defense in an underwhelming ACC, and Clemson is again the most likely team to reach the CFP.

Bryce Young, Alabama

Truthfully a competition in name only, Alabama is expected to enter the Bryce Young era in 2021.

As a true freshman, he made regular appearances in a string of blowouts. That will change dramatically in the fall, provided he officially beats out Paul Tyson and Jalen Milroe in the summer/fall camp.

Young is mobile and will frustrate defenses with his legs, but he'll put up most of his production as a passer. He threw for 13,250 yards and 152 touchdowns in high school.

As long as Alabama rounds out the receiving corps around John Metchie III, Young will be in great position to thrive in 2021.

All recruiting information via 247Sports. Stats from NCAA.com, cfbstats.com or B/R research. Follow Bleacher Report CFB writer David Kenyon on Twitter @Kenyon19_BR.