Uncertainty at Quarterback Plaguing College Football's Top Playoff Contenders

Defining the outlook of the 2018 college football season is simple: It all comes down to the quarterback.

Around the country, heralded preseason teams boast an elite running back here or dominant defensive line there, a terrific receiving corps or tenacious secondary.

But will the new quarterback thrive?

Will a returning starter recover after a disappointing 2017?

Or, in several cases, who is the quarterback?

Given the number of incumbents, the thought of uncertainty may seem misguided. Eleven of the top 15 teams in the Amway Coaches Poll bring back their signal-callers from 2017. Based on OddsShark championship odds, it's 13 of the top 18 schools.

However, the number of true competitions is remarkable.

Alabama is deciding between two-year starter Jalen Hurts and national championship hero Tua Tagovailoa. Kelly Bryant led Clemson to the ACC crown and College Football Playoff last season, but Trevor Lawrence has a legitimate chance to supplant the dual-threat QB.

In 2017, James Blackman took over for Deondre Francois at Florida State following the latter's torn left patellar tendon. Injuries contributed to Texas' waffling between Shane Buechele and Sam Ehlinger, and performance issues caused Notre Dame to shuffle Brandon Wimbush and Ian Book. All of those players are back.

USC will eventually choose one of Matt Fink, Jack Sears and prized freshman JT Daniels to replace Sam Darnold. Plus, Miami has a kinda-decided-but-still-not-over battle.

Malik Rosier will likely retain his hold on the starting job over N'Kosi Perry—something Mark Richt has repeated throughout the offseason, as noted by Christy Cabrera Chirinos of the South Florida Sun Sentinel. Still, the third-year head coach isn't slamming the door on a change during the season.

Keith Srakocic/Associated Press

"Malik is, without a doubt, the No. 1 quarterback going into fall camp," Richt said, "and right this minute, I'm not sure anybody's going to be able to unseat him, at least going into Game 1."

At least going into Game 1.

Perhaps that's the phrase worth remembering for these battles. Simply because Bryant or Blackman or Rosier opens the campaign behind center doesn't mean he'll finish there. Alabama, Texas, Notre Dame and USC could all make in-season changes.

Then, there are the schools in addition to USC preparing for a new thrower. Coincidentally, several of the more obvious starters for 2018 are found on rosters that lost their quarterbacks.

Michigan is expected to lean on Ole Miss transfer Shea Patterson. Oklahoma should get a year out of Kyler Murray before he joins the Oakland Athletics. Ohio State will tab Dwayne Haskins, and graduate transfer Joe Burrow is the favorite at LSU.

Nevertheless, only Patterson has considerable past participation, and he's never played more than seven games in a season. His talent is obvious, but his performance hasn't yet matched it.

While many of us in the college football world think we can project Murray, Haskins and Burrow, we're not certain what to expect from Washington's Jake Browning, Wisconsin's Alex Hornibrook and Stanford's K.J. Costello.

And the latter group, like Patterson, actually has experience.

Browning racked up 3,430 passing yards and accounted for 47 touchdowns in 2016, guiding Washington to a Pac-12 title and CFP berth. Last season, however, those numbers plummeted to 2,719 and 26, respectively. Which Browning shows up in 2018?

Hornibrook torched a vaunted, albeit short-handed, Miami defense in the Orange Bowl, yet he threw 15 interceptions in 2017. If Wisconsin's defense isn't the same level of elite—especially in the second half, when it ceded 74 points all year—tight losses could be headed the Badgers' way unless Hornibrook better protects the ball.

Although Costello put together a promising season for Stanford, he often had mediocre showings against ranked foes. He finished 2-3 against Top 25 teams over the final two months. The Cardinal will always be a threat, but that doesn't mean they're championship-worthy.

Austin Gay/Associated Press

Yes, there are a few settled jobs.

Auburn's Jarrett Stidham and Michigan State's Brian Lewerke are unquestionably secure. It's mostly the same for Georgia's Jake Fromm and Penn State's Trace McSorley, though Justin Fields and Tommy Stevens may steal a few snaps.

Familiar names are easily found. Several are former freshman All-Americans and all-conference picks, prized recruits or established starters. However, complete confidence in the quarterback is a rarity outside of a few locations.

True, it's not a revelation to say the performance of signal-callers will shape results. Defense always is and will remain an enormous factor in team success, and the quarterbacks' top effects on that unit—field position, time of possession—are indirect.

But in 2018, even the most respected rosters—ones expected to compete for the national championship—cannot be certain which player will be taking snaps when the season ends, or if experienced quarterbacks will ultimately be their downfall.

All recruiting information via Scout. Stats from cfbstats.com or B/R research. Quotes obtained firsthand unless otherwise noted. Follow Bleacher Report CFB Writer David Kenyon on Twitter @Kenyon19_BR.