Being a quarterback is exceptionally difficult.

For good reason, no position is under more scrutiny. Whether a college football team is chasing a national championship, conference title or double-digit wins, quarterbacks face the challenge of keeping a razor-thin margin for error intact.

And it's really, really tough to accomplish.

These choices are focused on teams with Top 25 potential. From there, we're looking at quarterbacks who played in 2021 but have a limited sample size or struggled with efficiency or top opponents.

Three years ago, Sean Clifford seemed like a future star. He threw for 2,564 yards with 8.3 yards per attempt with 23 touchdowns to seven interceptions, adding 402 rushing yards and five scores in his first season as a starter.

The last two campaigns haven't gone as well.

After posting an 11-2 record in 2019, Penn State dropped five straight games to begin 2020. Clifford ended the shortened season with 7.5 yards per attempt. He bounced back reasonably well early in 2021, but an injury and some mediocre games sent PSU to a 7-6 finish.

Clifford is the unquestioned starter, but 5-star signee Drew Allar is looming. If the Nittany Lions have a rough stretch, the clamors for change will resound.

Perhaps it's a fitting transition, given that Will Levis transferred from Penn State to start at Kentucky in 2021.

Most known for his mobility while at PSU, he put together a respectable year as a thrower. Levis completed 66.0 percent of his passes and averaged 8.0 yards per attempt for 2,826 yards and 24 touchdowns to 13 interceptions. He also rushed for 376 yards and nine scores, and UK won 10 games for only the fourth time in program history.

Since then, he's routinely been mentioned in 2023 NFL draft previews. Heck, he went sixth overall in a mock on Bleacher Report.

But the encore will likely be more difficult.

Virginia Tech transfer Tayvion Robinson eases the sting of losing Wan'Dale Robinson to the NFL, but he and Josh Ali, who played his final year of eligibility in 2021, combined for 145 catches and 1,935 yards. Levis will need to elevate the new-look receiving corps in 2022.

There isn't a more obvious candidate for the list.

Spencer Rattler earned a 5-star billing in high school, waited his turn at Oklahoma and thrived in his first opportunity. He recorded 3,191 yards and 34 touchdowns from scrimmage in 2020 and looked like the next Heisman Trophy-caliber player and top NFL prospect for OU.

And then, 2021 happened. Rattler had an unimpressive start to the season, and he ultimately found himself benched in favor of Caleb Williams by mid-October.

Following the season, he left OU for South Carolina, which started four quarterbacks last year.

Rattler has a fresh start, but rehabbing his reputation will be a major challenge. South Carolina's slate includes Georgia, Texas A&M and Clemson—all likely preseason Top 10 teams—along with Top 25 candidates Arkansas, Kentucky, Florida and Tennessee.

We know Anthony Richardson can run. Back-to-back 100-yard rushing performances to begin the 2021 season made that abundantly clear.

Now, we're waiting on the other part. Any number of qualifiers are acceptable—an inconsistent role behind Emory Jones, who transferred to Arizona State, and an overall dysfunctional offense, to name two—but Richardson tossed five interceptions in only 64 pass attempts.

That's not close to good enough.

Nevertheless, he's a classic "high-upside" NFL prospect who garners attention well before the production happens. Check out mock drafts this offseason, and he'll be a regular presence. ESPN's Todd McShay even pegged Richardson as the sixth overall pick, for example.

Entering the 2022 season, Richardson is all potential. Will he execute consistently within UF's tough schedule?

Oklahoma State came within about 1.7 inches of a Big 12 championship in 2021. This time around, though, the Cowboys are unlikely to have the luxury of a top-five defense.

In addition to losing coordinator Jim Knowles, the Pokes watched six key members head to the NFL or transfer portal. The defense may still be decent, but Oklahoma State probably needs to score more points in 2022.

That pressure lands on Spencer Sanders.

The bright side is he's a legitimate dual-threat weapon with 1,565 rushing yards in three seasons. The problem is he's not immune to panicked decisions, which has resulted in some crushing turnovers in key games, most recently in the Big 12 title loss to Baylor.

Eliminating that trend is no easy task, but it could be the difference between a seven-win season and a return trip to Arlington with a league crown at stake.

Similar to Clifford in 2019, Kedon Slovis had a breakout year. He replaced an injured JT Daniels, helped USC win eight games and ended the season with 3,502 yards and 30 touchdowns to nine interceptions.

And then—like his Penn State counterpart—the next two years didn't treat Slovis as well. His efficiency dropped in 2020, and he rarely looked comfortable during an injury-affected 2021.

Slovis left USC in the offseason and landed at Pittsburgh, where he's the front-runner to replace Kenny Pickett.

Even though they lost receiver Jordan Addison to USC, the Panthers are reigning ACC champs. They've had a glimpse of success, as Slovis did in 2019, and are banking on him to keep the program at this height.

The numbers from Taulia Tagovailoa's first full season as Maryland's starter look promising. He notched a 69.2 percent completion rate with 3,860 yards (8.1 per attempt) and 26 touchdowns to 11 interceptions.

Context, as always, is valuable.

Against nine unranked teams, he averaged 321.8 yards (8.9 per attempt) with 19 passing scores to only two picks. Flip to the four Top 25 opponents, and his numbers tanked. Tagovailoa mustered 241.0 yards per game (6.5 per attempt) and seven touchdowns to nine interceptions.

Not only do the Terps play intradivision Michigan, Michigan State, Ohio State and Penn State in 2022, but they also have a trip to Top 25 regular Wisconsin.

Maryland has a talented receiving corps around Tagovailoa, but his connection with those players needs to appear in the biggest games.

During the 2020 campaign, DJ Uiagalelei dazzled in two unexpected starts. He accounted for 808 yards and six touchdowns from scrimmage, which contributed to immense and understandable hype before the 2021 season.

Even if you're not aware of what happened last year, you understand where this is headed.

Uiagalelei, quite frankly, had a terrible 2021` season. He ranked 98th or worse nationally in completion percentage (55.6) and yards per attempt (6.0), tossing nine touchdowns with 10 interceptions. Clemson still managed 10 wins, but it was primarily a credit to the other side of the ball.

The good news? Led by a potentially dominant line, the defense should be even stronger and the foundation of a title contender.

To reclaim the ACC and legitimately compete for a national championship, though, the Tigers need the 2020 version of Uiagalelei to appear. Otherwise, they could be turning to 5-star freshman Cade Klubnik.

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