Oklahoma State receiver James Washington

To contend for a national championship, you need a few things. One of them is an X-factor. That doesn’t necessarily mean a star player — though it certainly can — as much as a guy who just keeps the wheels turning and turns in a good game every week, regardless of opponent. A guy you can’t win without. Every good team has one. It’s a vital part of a winning formula.

Here are the biggest X-factors for every team in college football’s top-25.

1. Alabama: Minkah Fitzpatrick, cornerback

Fitzpatrick, an All-American last season, is well on his way to repeating the achievement this year. The junior may well be the best cornerback in the country. He consistently shuts down whichever receiver has the unfortunate job of lining up across from him. Fitzpatrick is as big a reason as anyone for Alabama having the best defense in the country.

2. Penn State: Saquon Barkley, running back

This one was pretty easy to figure out. Barkley has 1,205 all-purpose yards through Saturday, when he went for 108 on the ground, 53 in the air and scored three touchdowns in the Nittany Lions’ beatdown of Michigan. He’s currently tops the list of Heisman Trophy favorites, and it’s hard to see how anyone else wins it. Every week, Barkley adds another play (like this) to a season-long highlight reel.

3. Georgia: Terry Godwin, wide receiver

Terry Godwin college football

When quarterback Jacob Eason went down with an injury in the Bulldogs’ first game of the season, things didn’t look good. Jake Fromm, the backup, was a true freshman. Through seven games, however, Fromm has settled in easily and Georgia looks one of the toughest SEC challengers Alabama has had in years. Give Godwin some credit for that. The junior has 16 receptions and 369 receiving yards. That includes a stunning touchdown in a close win at Notre Dame, Fromm’s first as the starter. Fair to say he played a pretty big role in helping Fromm find his legs.

4. TCU: Ben Banogu, defensive lineman

Banogu is in his first year at TCU after transferring from Louisiana-Monroe. And boy is he making an impact. The junior has 8.5 tackles for loss and 4.5 sacks in just six games. He’s also forced two fumbles and made 31 tackles. TCU’s defense is an underrated part of its success — the Horned Frogs rank 11th in defensive S&P+, which gives them a notable leg-up on the rest of the Big 12. Banogu’s presence is a big reason why.

5. Wisconsin: Garret Dooley, linebacker

The Badgers have won with defense so far. Dooley is one of the keys to their front seven. The senior linebacker has come into his own this season with 5.0 sacks and eight tackles for loss. That’s tied for the Big Ten lead in sacks and third in the conference in TFLs. Dooley just makes Wisconsin’s defense — ranked sixth in S&P+ — work the way it does.

6. Ohio State: Nick Bosa, defensive end

Bosa is following in his brother’s footsteps at Ohio State. It’s only his sophomore season and Bosa has 4.0 sacks with 10 tackles for loss. He’s the chief havoc-wrecker on a defensive line that has an absurd 9.7 percent havoc rate, per Football Study Hall. Next week’s matchup against Penn State — which could determine the Big Ten East — may come down to whether Bosa can get in the backfield to stop Saquon Barkley.

7. Clemson: Clelin Ferrell, defensive end

You could slot in almost any member of Clemson’s front seven and make a good case. Here’s Ferrell’s: the redshirt sophomore has 5.5 sacks and 7.5 tackles for loss in seven games. That’s as a redshirt sophomore, on arguably the best defense in the country. And he’s already a linchpin. No doubt he’s surrounded by greatness, but Ferrell is a huge X-factor for Clemson.

8. Miami: Braxton Berrios, wide receiver

Miami receiver Braxton Berrios

Berrios leads the Hurricanes in receiving yards with 337 on 25 catches in six games. When Miami quarterback Malik Rosier is in a tight spot, he looks to Berrios. The Hurricanes’ nail-biting wins over FSU and Georgia Tech were Berrios’ best games — he had 14 of his 25 receptions in those two contests. He also put up two touchdowns against the ‘Noles. We’re going to hear a lot about Miami in the coming weeks as their do-or-die matchup against Notre Dame approaches. No doubt Berrios will be at the front of the discussion.

9. Notre Dame: Josh Adams, running back

The junior running back has been absolutely crushing it in South Bend. Adams, through seven games, has already surpassed his rushing yard total from last season. He’s put up 967 yards through Saturday’s action thanks to a ludicrous 9.2 per carry. Adams also has eight touchdowns, including three against the Trojans on Saturday. He is the lifeblood of Notre Dame’s offense.

10. Oklahoma: Trey Sermon, running back

Quarterback Baker Mayfield gets the Heisman buzz, but Sermon does a lot in terms of making the Sooners’ offense tick. The freshman from Marietta, Georgia has 487 yards on the ground this year. He’s also gotten better as the season has come along, averaging over 4.5 yards per carry in each of Oklahoma’s last four games. He even completed a 42-yard pass in the Red River Showdown against Texas.

11. Oklahoma State: James Washington, wide receiver

Without Washington at his disposal, Mason Rudolph is just another Big 12 quarterback with empty stats. Washington has 38 receptions and 914 receiving yards for the Cowboys. Not only does he lead the Big 12 in receiving yards, but Washington is fifth on the all-time conference list. If he keeps putting up massive numbers, he’ll be leading it by the year’s end.

12. Washington: Vita Vea, defensive lineman

If you watch a Huskies game, it’s impossible to miss Vea, a 6-foot-5, 340-pound monster in the middle of the line. Vea doesn’t put up huge numbers — he has just 17 tackles this season. However, he consistently wreaks havoc in the middle of the line. Vea makes a big impact in the run game just by filling space. He’s been a huge reason for Washington’s second-ranked defense by S&P+.

13. Virginia Tech: Andrew Matuapuaka, linebacker

The Hokies have quietly managed to stay in the conversation, thanks to their defense, and Motuapuaka is one of the best players on that unit. The senior has 44 tackles through seven games. He’s also put up 4.5 tackles for a loss and 2.5 sacks, along with a forced fumble. Motuapuaka is all over the field for Virginia Tech. Don’t count the Hokies out just yet.

14. NC State: Bradley Chubb, defensive end

Bradley Chubb

Chubb has a strong argument as the best defensive player in the ACC right now. The senior edge rusher has made the eyes of NFL scouts pop on a weekly basis. He has 6.5 sacks and 13.0 tackles for loss, both of which lead the conference. The Wolfpack’s defense might fall apart without him.

15. Washington State: Hercules Mata’afa, defensive lineman

The wonderfully-named junior has been a consistent star of #Pac12AfterDark this season. Mata’afa has 6.0 sacks and 13.0 tackles for a loss on the year. Though consistency has been a slight issue — he has two games without a tackle this year — when Mata’afa is at his best, he bookends a fearsome Cougars pass rush. Once he goes to the NFL after this season, Washington State won’t be the same.

16. Michigan State: LJ Scott, running back

Scott has had some off-field troubles and on-field inconsistencies. But when he’s at his best, it’s hard to argue that the junior doesn’t give the Spartans that extra spark. The best example of that from this season is the Minnesota game two weeks ago in which Scott went off for 194 yards and two scores. However, he’s been a major contributor in most of Michigan State’s wins, despite not going over 100 yards in any other games. Take Saturday against Indiana — Scott ran for  87 yards and the game-sealing touchdown. Even without eye-popping numbers, Scott is a consistent contributor for Mark Dantonio’s squad.

17. South Florida: Mazzi Wilkins, cornerback

The Bulls have built their defense around takeaways, with 15 interceptions on the season. Wilkins is responsible for three of them. The junior corner also leads the AAC with eight passes defensed. USF is likely headed for a showdown with Central Florida with a New Year’s Six bowl invite on the line. The key matchup in that game could pit Wilkins against the next player on this list.

18. Central Florida: Tre’Quan Smith, wide receiver

If you haven’t paid attention to G5 football this season, here’s a stat that may surprise you: Central Florida, according to S&P+, has the third-best offense in the country. Yup, the Knights are legit, and Smith is a huge weapon in their passing game. The junior wideout has 436 yards and eight touchdowns on 21 receptions this season. Even when opposing defenses shut Smith down, he manages to make an impact. Last week against Navy, he had just one catch: a six-yard touchdown. Watching him go up against Wilkins next month is going to be a lot of fun.

19. Auburn: Kerryon Johnson, running back

Auburn running back Kerryon Johnson

With Kamryn Pettway disappointing at running back, the Tigers needed someone to step up. Enter Johnson. The junior has 723 yards on the ground and 14 touchdowns in only six games! Despite playing two games less than some teams, Johnson leads the country in rushing touchdowns and the conference in rushing yards. That’s pretty impressive for someone who wasn’t expected to start before the season.

20. Stanford: Bryce Love, running back

It’s fair to say the expectations were high for Love coming into the year. It’s also fair to say he’s done what seemed impossible: adequately replace Christian McCaffrey. Love’s 1,387 rushing yards lead the country, as do his 1,406 yards from scrimmage. He has a conference-leading 11 rushing touchdowns as well. Perhaps the most impressive stat: 10.3 yards per attempt. Love deserves more Heisman buzz — he’s the only running back in the country who’s been comparable to Saquon Barkley.

21. USC: Deontay Burnett, wide receiver

Burnett has been a safety blanket for quarterback Sam Darnold this season. The junior has already surpassed his 2016 reception total with 57 catches through Saturday’s action. That leads the Pac-12, as do Burnett’s 739 receiving yards. With Burnett nearly doubling the reception total of any teammate, it’s clear that Darnold has an extra level of trust with him.

22. West Virginia: David Sills, wide receiver

Sills has one of the best stories out there. He signed a letter of intent to USC in seventh grade — eventually decommitting to go to West Virginia. He played four games at quarterback for the Mountaineers in 2015 and struggled, so he transferred to El Camino College for a year. When he came back to WVU this year, Sills — who continued at quarterback at El Camino — was a wide receiver. And, wouldn’t you believe it, he leads the country with 15 receiving touchdowns. He’s been absolutely pivotal for the Mountaineers and the story makes it all the more better

23. LSU: Devin White, linebacker

White, a sophomore from Springhill, Louisiana, is already one of the best defensive players in the country. Through eight games, White has 80 tackles, which is good enough to lead the SEC by a wide margin. That includes 3.5 sacks and 7.5 tackles for a loss. However, as a linebacker, most of White’s production has come on the second level. He’s been an absolute force there for LSU. It is impossible to watch the Tigers and not be impressed by No. 40.

24. Memphis: Anthony Miller, wide receiver

If you want to know how important Miller is to Memphis’ passing game, you don’t have to look hard. The senior has 784 receiving yards, leading the team. Tony Pollard, who has the second-most, clocks in at 291. Miller has over 2.5 times the receiving yards of any of his teammates. This on an offense that ranks 20th in S&P+. Fair to say he’s a pretty big piece for the Tigers.

25. Iowa State: Joel Lanning, linebacker/quarterback

Though Lanning plays both ways for the Cyclones, the vast majority of his contributions are on defense, especially as Kyle Kempt has grown into a solid quarterback. It almost gets overshadowed because of how often the media discusses him as a two-way player, but Lanning is one of the better linebackers in the Big 12. He has 64 tackles, 2.5 sacks, and 6.0 tackles for a loss this season. Lanning also picked one off against Akron for good measure. That’s an impressive resume for someone who was a full-time quarterback until this season.