Biggest College Football X-Factors Who Can Make or Break Their Team

College football is filled with stars, but certain X-factors hold the keys to their team's fate.

For teams like Virginia Tech, which is coming off its first losing season in 26 years, it may be a difference-maker on defense in coordinator Bud Foster's final year at the helm of the Hokies defense. Others like Florida State are turning to a transfer for help to fill a huge deficiency.

Plenty of quarterbacks fit this mold, too, from Nebraska sophomore Adrian Martinez to Ohio State's Justin Fields. 

If the following players stay healthy and emerge as stars, they could be the pivot points for their respective teams' seasons.

 For more college football and NFL draft talk, check out the Stick to Football podcast with B/R's lead draft expert Matt Miller.

Perhaps no head football coach in the nation is more tied to the immediate success of his quarterback than USC's Clay Helton in 2019. 

The Trojans coach is on shaky footing following a losing campaign, which is why he went out and made two dynamic offensive coordinator hires this offseason to try to squeeze the potential stardom from sophomore quarterback JT Daniels.

Helton initially lured former Texas Tech head coach Kliff Kingsbury to Los Angeles, but he wound up getting the Arizona Cardinals head coaching gig, where he'll mentor No. 1 overall pick Kyler Murray. After Kingsbury's abrupt departure, Helton hired North Texas offensive coordinator Graham Harrell.

Harrell is another former Red Raiders signal-caller who has become a young guru play-caller. How he meshes with Daniels is a major focal point of the offseason and could be the biggest cog in a Trojans turnaround.

The 6'3", 210-pound freshman who was once the second-ranked high school pro-style passer was sporadic at best last year, completing less than 60 percent of his passes for 2,672 yards, 14 touchdowns and 10 interceptions. The offense sputtered with him at the helm, and playmakers were hard to find.

USC's cupboard is stocked with young talent this year, though, and Daniels could take a major step forward. It's easy to forget he reclassified to an 2018 recruit and should have been a senior in high school, after all.

Daniels' maturity is paramount, and his makeup is still premiere. Drawing every bit of that out of him this year can help the Trojans make up for some other deficiencies.

One of the most fun stories to follow this season is going to be in Columbus, Ohio, where storylines abound for the Buckeyes.

Not only is this the first year without Urban Meyer on the sideline since 2011, but record-setting quarterback Dwayne Haskins is off to the NFL as well.

Replacing him is former Georgia signal-caller and elite prospect Justin Fields, who the NCAA granted an immediate waiver to allow him to suit up. It's a good thing, too, as OSU's quarterback depth is razor-thin.

Although Fields has breakout potential, he hasn't run away with the Buckeyes job this fall. Kentucky transfer Gunnar Hoak isn't out of the race yet, head coach Ryan Day recently told 247Sports' Patrick Murphy.

Is that gamesmanship? A chance to rev up some healthy competition? Or is Fields genuinely not in position to start yet?

Who knows, but the Buckeyes have so much talent on offense that Day needs to make the correct decision.

If Fields lives up to his potential, he would put OSU on a championship level. But potential doesn't equal production. While there's no shame in standing on the sideline while a proven star like Jake Fromm flings dimes, this is his chance to lead his own elite program.

Tate Martell proved in Miami that it isn't always a slam dunk to transfer. The safe money is on Fields taking that first snap for the Buckeyes, though. How he fares will determine whether this is a rebuilding season or if OSU is a threat to win the Big Ten yet again.

With all of the talent head coach Tom Herman and defensive coordinator Todd Orlando has recruited to Texas over the past few seasons, it's time for those star rankings to start paying dividends on the field.

The Longhorns looked to be back late last season when they beat Georgia in the Sugar Bowl 28-21. 

SEC sympathizers might argue the Bulldogs were sleepwalking because they felt disappointed about being left out of the College Football Playoff. Whether you believe that is up to you. What's not up for debate is which team was clearly better on that night.

Texas' young secondary spent a lot of the regular season in a baptism-by-bludgeoning thanks to the high-flying offenses of the Big 12. But in the Sugar Bowl, the Bulldogs frustrated Jake Fromm and showed off a lot of potential stars in the process.

One of those is B.J. Foster, a former high-profile recruit who should slide nicely into the nickelback spot vacated by the steady P.J. Locke III.

Foster is a big-hitting player who also has a nose for the ball and could be the perfect complement to Caden Sterns on the back end. As a true freshman, Foster made six starts, finishing with 46 tackles, including nine for a loss, 2.5 sacks, two forced fumbles and an interception.

If Foster takes another step forward and the 'Horns can put six dependable defensive backs on the field, they will be a threat to upend rival Oklahoma in the Big 12.

Florida quarterback Feleipe Franks was about to be benched after a putrid outing against Missouri last year. But after a practice injury to Kyle Trask left him in the starting lineup, he turned around his season.

Franks went on to account for 12 total touchdowns and zero interceptions in a 4-0 stretch to end the year, stamping the season with wins over South Carolina, Idaho, Florida State and Michigan in the Peach Bowl.

That ended the talk (at least for the time being) that the 6'6" Franks wasn't a Dan Mullen style quarterback.

With the Gators nursing high expectations as a potential contender in the SEC East, they again need—and now expect—a big season from the rising junior. He must improve on his completion percentage, and he also must settle into games quicker.

While rising redshirt freshman Emory Jones may be the future of the Gators, this is currently Franks' team. Whether he seizes it and surges will determine the Gators' ceiling.

Florida has dealt with its share of off-field turmoil this offseason, and there are plenty of questions surrounding the team. But if Franks takes another step forward and builds off the final quarter of his 2018 season, the Gators can be a major threat to the Dawgs. 

Former Notre Dame quarterback and graduate transfer Brandon Wimbush is expected to lead the way for the UCF Knights this season.

UCF now must find him some weapons.

Running back won't be an issue with Greg McCrae and Adrian Killins combining to form one of the most dynamic duos in college football. But the Knights desperately need a go-to playmaker in the receiving corps after Dredrick Snelson's early departure to the NFL. 

The biggest candidate to fill that void is 6'5", 211-pound redshirt senior Jacob Harris, who has yet to catch a pass in college.

Head coach Josh Heupel told the Orlando Sentinel's Brian Murphy that he expected Harris, junior receiver Marlon Williams and utility player Otis Anderson to shoulder more of a load this season.

"He brings it, the same competitive nature, every single day," Heupel said. "Weight room, conditioning, practice habits, he's pushing himself to be his absolute best."

Harris said he emulates Tampa Bay Buccaneers receiver Mike Evans, and if he can become a pro prospect, it would be a remarkable journey. He began playing football as a high school senior, and he didn't line up as a receiver until he went to Western Kentucky.

After transferring to UCF and taking a year off in 2016, he walked on in 2017 and went from scout team to special teams to earning a scholarship last year.

Harris is now poised to help Wimbush and the running back duo keep the Knights at the forefront of dynamic college offenses and on the cusp of the playoff conversation.

Nebraska rising sophomore Adrian Martinez may be college football's next megawatt playmaker alongside Clemson's Trevor Lawrence and Alabama's Tua Tagovailoa.

Martinez is the perfect quarterback to run head coach Scott Frost's offense. He was a maestro as a true freshman when healthy, throwing for 2,617 yards, 17 touchdowns and eight interceptions while running for 629 yards and eight scores.

Tom Shatel of the Omaha World-Herald has witnessed plenty of great Cornhusker quarterbacks in the past, but he wrote earlier this month that everybody should just "enjoy the show" when it comes to Martinez.

Nebraska and Frost won't undergo an overnight transformation in the rugged Big Ten. But having a difference-maker at quarterback who can will his team to wins is an intangible that doesn't come around often.

Without Martinez, the Cornhuskers are an ordinary team full of young guys who are trying to rebuild a once-proud program under a hot young coaching name. With Martinez, all of that could coalesce into something special.

In 2018, Virginia Tech experienced its first losing season in 26 years. Besides offensive injuries, the ineptitude of the defense shouldered much of the blame, which is nearly unheard of in the Bud Foster era.

The Hokies ranked 98th in FBS in total defense, and they also allowed 31.0 points per game, which was a career-worst for a Foster-led unit. With the legendary coordinator set to retire after this season, he hopes to go out on a high note.

The pieces of the puzzle are there, as nine returning starters should make for an improved unit. Led by Rayshard Ashby, who had 105 tackles and 9.5 for a loss last season, the linebacking corps should be a strength, but the Hokies desperately need stability on the back end.

That's where Divine Deablo comes in.

Playing alongside a solid starter in Reggie Floyd, Deablo has breakout potential. The Hokies need him to become a star. 

With former Hokies player Justin Hamilton taking over for Tyrone Nix as the new unit coach, there should be continuity and a familiarity with Foster that was lacking last season. Deablo could solidify the unit and make a major impact.

If he grows the way he's expected to, the safeties could be the defense's strongest unit. If not, the Hokies will be scrambling for answers again.    

If you're worried about Oklahoma's offense, you haven't watched much college football lately.

Coach Lincoln Riley turned Baker Mayfield and Kyler Murray into the past two Heisman Trophy winners, and the Sooners won the graduate transfer sweepstakes when Alabama quarterback Jalen Hurts elected to play his final season in Norman.

Defense is one of the main reasons why the Sooners haven't won a national championship trophy in recent years. That's why Riley went out and lured Ohio State co-defensive coordinator Alex Grinch to be the new defensive coordinator at Oklahoma.

With the Sooners expected to light up scoreboards again this season, Grinch needs to solidify OU's defense. One of the best ways to do that is by getting pressure on the many excellent quarterbacks in the Big 12.

Enter Ronnie Perkins.

As a freshman in 2018, the former top-100 prospect finished with eight tackles for a loss and five sacks, and he should thrive with the system change. If he and some of his pass-rushing mates can get to the quarterback, it will drastically change OU's defense.

The Sooners have notched some recent recruiting victories to upgrade the talent in their secondary, and those youngsters need all of the help they can get in the pass-happy Big 12. Look for Perkins to have a monster season and Oklahoma to improve its championship hopes as a result.

It may be time for the Iowa State Cyclones to break out.

Yes, they're desperately going to miss all-star running back David Montgomery, who headed to the NFL. But head coach Matt Campbell has recruited well enough to keep that stable of capable runners in the backfield.

The true difference-maker is sophomore quarterback Brock Purdy. He won't get as much attention as Lawrence, Tagovailoa, Daniels or even Martinez, but you should familiarize yourself with him nevertheless.

In games where Purdy took the most snaps last season, the Cyclones were 9-2, with losses to Texas and Washington State. He finished the year completing 66.4 percent of his passes for 2,250 yards, 16 touchdowns and seven interceptions and added 308 rushing yards and five touchdowns.

Purdy needs to be smarter as a sophomore, learning when to get out of bounds or slide out of harm's way. Iowa State's season hinges on his health and his ability to orchestrate the run-pass option.

Purdy told CycloneAlert's Alex Halsted:

"Last year, I learned my lesson. I tried to lower my shoulder here and there, like against Oklahoma State. I've got to be smart and get down when I need to, and a thing I did in high school was try to extend plays all the time, where here, if you've got a guy coming at you, you've got to get down or out of bounds. It was good I have that experience from last year and understand that these guys are bigger and stronger and it's not high school anymore."

If he stays upright, Iowa State could emerge as a sleeper in the conference.

There's no way to sugarcoat Willie Taggart's first year with the Florida State Seminoles.

A big reason for Florida State's first bowl-less season in 37 years was the ineptitude of the offensive line, which couldn't protect anybody.

Though Lance Dickerson transferred to Alabama, three contributors exhausted eligibility and FSU hasn't overhauled that unit, there's much more optimism this preseason. One of the biggest reasons is graduate transfer Ryan Roberts, who will help fortify the 'Noles line as the starting right tackle.

Roberts played in 36 games at Northern Illinois. The rest of the Seminoles' projected offensive line has only 12 career starts between them. 

FSU averaged 2.8 yards per rush last season, which was the worst mark among Power Five teams. The Seminoles also gave up 36 sacks.

"Last season is done," Roberts told Warchant.com's Corey Clark. "Nobody is worried about that anymore. All I've seen since I've been here is guys who want to work hard, guys who want to get better every single day, guys who are committed to helping this team win."

Roberts needs help. No offensive lineman can win games on his own. But the Seminoles got a major puzzle piece when he decided to spend his final collegiate year in Tallahassee.

Penn State not only needs to find a replacement for quarterback Trace McSorley, but it also needs to unearth another star running back.

Two years ago, Penn State deployed a generational talent in Saquon Barkley, who is now tearing up the NFL for the New York Giants. Miles Sanders replaced him last season and finished with more than 1,400 yards from scrimmage.

He's now gone as well, so PSU needs to find another playmaker in the backfield.

Freshmen like Noah Cain and redshirt sophomore Journey Brown can solidify the depth of the backfield, but the Nittany Lions are only going to go as far as Ricky Slade takes them.

The 5'9", 185-pounder was the nation's top-ranked all-purpose back in the 2018 class and a major recruiting coup for Franklin. He has the ability to transform Penn State's offense with his speed.

Though Slade hasn't shown it yet, he can impact the game catching the ball, too. 

Franklin has done an exceptional job loading the Penn State backfield with capable talents, and he could use four or five runners as the season progresses. But Slade is a next-level impact player who could emerge as one of the Big Ten's biggest weapons.

If he does so, Penn State may rebound nicely.

Georgia head coach Kirby Smart has settled in at his alma mater, which is going to be an SEC force for several years to come.

The Bulldogs are outfitted with proven talent at nearly every position, but that isn't the case with their receiving corps. Although they've brought in some high-level recruits, they still need a go-to option.

That's where California transfer Demetris Robertson comes in.

In 2016, Robertson caught 50 passes for 767 yards and seven touchdowns for then-Cal coach Sonny Dykes. But he caught only seven passes for 70 yards in two games in 2017 and then transferred to Georgia.

Robertson was a nonfactor in 2018 for a Dawgs team that barely missed the playoffs, but with Riley Ridley, Mecole Hardman, Isaac Nauta, Terry Godwin and Jeremiah Holloman no longer on the roster, quarterback Jake Fromm needs capable targets.

Georgia is built to compete for championships now, but it needs a balanced offense to do that. Robertson is the key to making it a reality.

Arizona Wildcats quarterback Khalil Tate entered the 2018 season as a Heisman Trophy candidate, but he didn't finish it as one. 

Although Tate threw for 2,530 yards, 26 touchdowns and eight interceptions, his rushing production significantly declined. He ran for 1,411 yards and 12 touchdowns in 2017, but he finished with only 224 rushing yards last season.

The bumps in the road with Mazzone were partly to blame.

"I think it's kind of like when you're married," Tate told Arizona Desert Swarm's Brian J. Pedersen. "During the first year, it's always going to be kind of rocky. But after time and after you go through a few things, things are starting to become easier."

Tate is now healthy and has a year's worth of experience with Mazzone. It wouldn't be shocking if he displays more of his dual-threat ability this season. 

In a wide-open Pac-12 South, a Wildcats resurgence could lead to a spot in the conference title game.

It all hinges on Tate, who is a difference-maker that gives defenses nightmares at his peak. 

Oregon head coach Mario Cristobal used his recruiting prowess to pull in the seventh-best class nationwide, headlined by 5-star defensive end Kayvon Thibodeaux.

Not only was the 6'4", 240-pound weak-side defensive end widely recruited, but he represented a major victory in other ways, too.

For the Ducks to be successful, they must have a massive recruiting presence in California. Thibodeaux was the top-ranked player in the state. The top five players in Oregon's 2019 class hailed from the Golden State, and Cristobal grabbed 11 total from there.

That's a major win, and perhaps a sign of things to come. But Oregon needs those guys to produce right away.

While Penn State transfer Juwan Johnson is a key piece of the puzzle on offense, the Ducks need to fill their defensive gaps.

That's where Thibodeaux comes in.

"Explosive, powerful and a lot of ability," Cristobal told The Oregonian's John Canzano. "He's made a lot of plays. It's great that he gets to go against a veteran offensive line and a veteran tight end."

The Ducks aren't going to win the Pac-12 unless young players like Thibodeaux are instant-impact stars. 

The Auburn Tigers were expected to battle Alabama in the SEC West last season, but they instead limped to an 8-5 record.

The Tigers' quarterback battle will command plenty of attention over the coming weeks, but they also have to shore up a running game that was pedestrian last year. Prior to 2018, Auburn had a 1,000-yard rusher in each of its previous nine seasons.

New assistant and former Tigers great Carnell "Cadillac" Williams wants his guys to run with an attitude this year.

"I'm sure, just like everybody else, them guys, they kind of read or see what was Auburn's weak spot—and, you know, most times it points back to the running back room," Williams told Justin Lee of the Opelika-Auburn News. "I think guys individually, and collectively, have took that as a challenge and ran with it."

While speedster Shaun Shivers and veteran Kam Martin will garner plenty of carries, sophomore JaTarvious Whitlow has the highest ceiling. He led the Tigers with 787 yards last season and scored six touchdowns while averaging 5.2 yards per carry.

With the Tigers bringing along a young signal-caller, they need to be able to lean heavily on the running game. The best Gus Malzahn offenses had plenty of stars at that spot.

Whitlow needs to be the next if Auburn is going to rebound.

 

All recruiting information is from 247Sports, and rankings are from the 247Sports composite. All stats are from CFBStats.com.

Brad Shepard covers college football for Bleacher Report. You can follow him on Twitter, @Brad_Shepard.