Three of the top four teams in the first College Football Playoff rankings do not have a clear-cut Heisman Trophy candidate. Two running backs, Saquon Barkley and Bryce Love, who had been trying to run away from the field have fallen back to the pack after a rough couple weeks. The preseason favorite, Sam Darnold, has had an inconsistent season, and the defending winner, Lamar Jackson, is playing for a 5-4 team that's in last place in its division.

Baker Mayfield, the stage belongs to you.

Mayfield surged to the top of the Heisman conversation after his sterling performance at Ohio State in Week 2, fell back after Oklahoma lost to Iowa State and has now recaptured the pole position in the race after throwing for 598 yards and five touchdowns in the Sooners' 62-52 Bedlam win over Oklahoma State, during a week in which other top candidates saw their resumes take a hit.

As I wrote in September, Mayfield is trying to become the 15th player to finish in the top 10 of the Heisman vote three times and just the seventh player to finish in the top five three times. The six players with three top-fives all won the award at least one of those years and are among the most legendary players in the sport's history: Doc Blanchard, Glenn Davis, Doak Walker, Archie Griffin, Herschel Walker and Tim Tebow.

Mayfield, who began his career as a walk-on at Texas Tech and earned the Week 1 starting job as a freshman, finished fourth in his first season as Oklahoma's quarterback in 2015 and third last year, when he was a finalist. In doing so in 2016, he set the FBS single-season record for passer rating (196.4). Now, despite losing head coach Bob Stoops, top receiver and fellow Heisman finalist Dede Westbrook and star tailbacks Samaje Perine and Joe Mixon, Mayfield is trying to surpass all he accomplished his first two years in Norman, with the help of offensive-coordinator-turned-head-coach Lincoln Riley.

Can anybody catch Mayfield in the next four weeks? Let's break down the field for the home stretch of the season with three weeks of regular-season games left before the conference championship games.

The Frontrunner

Baker Mayfield, QB, Oklahoma

71.7 percent, 3,226 yards, 28 TDs, 5 INTs, 201.6 rating, 11.9 YPA
62 carries for 181 yards and 5 TDs

The senior is checking just about every box needed for a Heisman candidate: He's a known star who's had big performances in big games near the start and end of the season. He threw for 386 yards and three TDs in a win at Ohio State and a school-record 598 yards and five TDs in a win at Oklahoma State. He also had a stellar Red River Rivalry game against Texas. Mayfield has thrown multiple TD passes and completed over 60 percent of his passes in every game, and he's averaged over 10 yards per attempt in seven of nine games. As a passer, Mayfield is having one of the best seasons in college football history, and he's trying to lead Oklahoma to a third straight Big 12 title and second playoff bid in three years. Mayfield has a clear Heisman lead now, and he can take an even bigger lead on Saturday when Oklahoma hosts TCU, which has the Big 12's best defense. It could actually be the first of two meetings with the Horned Frogs, as a Big 12 title game rematch is possible. How Mayfield played against Ohio State and Oklahoma State put him in position to lead the Heisman race. How Mayfield plays against TCU could win it.  

Top Challengers

Listed in alphabetical order, the players who have been in the conversation for all or part of the year.

Josh Adams, RB, Notre Dame

137 carries for 1,191 yards and 9 TDs

Do not take this as a knock on Adams: He has not been the best player on the Notre Dame offense. That's because the biggest story of the season has been the dominant play of the offensive line, led by Quenton Nelson and Mike McGlinchey. But Adams has taken full advantage of his stellar blocking to deservingly become a Heisman candidate, running with some power and showing a knack for making big plays: He averages 8.7 yards per carry, has two 200-yard games and has 12 runs of 30-plus yards. After sitting out most of the game against Wake Forest, the spotlight will be on Adams for a potential Heisman-making performance at Miami. He's the clear top candidate for the Irish, given that Brandon Wimbush hasn't done enough as a passer to get consideration.

Saquon Barkley, RB, Penn State

152 carries for 864 yards and 9 TD
39 catches for 504 yards and 3 TDs
1 TD pass
2 kick return TDs

The most talented player in college football doesn't always win the Heisman, just as the Heisman frontrunner at the midway point of the season often doesn't win it, either. Unfortunately for Barkley, both might prove to be true for him. Widely regarded as a top-10 pick for the 2018 NFL Draft, Barkley is a highlight-creating all-purpose star who runs with speed, power and unmatched agility. He vaulted to the top of the Heisman race with countless highlights and 358 all-purpose yards -- 211 rushing, 94 receiving, 53 kick return -- in a win at Iowa. Even when he has been contained, he's typically made an attention-grabbing big play or two most weeks. However, offensive line problems have held back his Heisman campaign, as he's been hit too often in the backfield before he has any chance to make a play, particularly in back-to-back heartbreaking losses to Ohio State and Michigan State that ended Penn State's playoff hopes after it rose to No. 2 in the polls. Barkley is still in the race -- perhaps the top challenger to Mayfield, given the recognition he's earned all season -- but, to reignite his case down the stretch, he'll need big performances and memorable highlights in games against Rutgers, Nebraska and Maryland that otherwise won't draw much attention.

J.T. Barrett, QB, Ohio State

67.5 percent for 2,375 yards, 28 TDs, 5 INTs, 168.2 rating, 8.5 YPA
101 carries for 517 yards and 5 TDs

Barrett still may hang around in the conversation, but what happened in Iowa City last week ends his chances of actually winning the Heisman: a 55-24 loss to Iowa in which he was intercepted four times. Given his lackluster performance in the loss to Oklahoma, Barrett's case for still being in the race centers around big numbers in a series of games against teams with losing records and, most of all, his brilliant, near-perfect performance in leading a comeback win over Penn State.

Lamar Jackson, QB, Louisville

60.4 percent, 2,808 yards, 18 TDs, 6 INTs, 147.3 rating, 8.6 YPA
163 carries for 1,029 yards and 14 TDs

I wrote a few weeks ago that Jackson's 2017 season has been underappreciated. The 2016 Heisman winner has been a brilliant one-man show who's been stuck dealing with continued struggles on the offensive line and a drastic drop-off in performance by the Louisville defense. After ending last season on a three-game losing streak, Louisville is just 5-4 in 2017 with a 2-4 record in the ACC. Jackson has been spectacular and fun, again. He deserved to win the Heisman last year, and if he finishes this season strong, he'll have the numbers and highlights to deserve a second trip to New York as a finalist. But he's fighting against both his team's performance and the ridiculously high standard he set last year, which makes winning seem nearly impossible.

Bryce Love, RB, Stanford

151 carries for 1,456 yards and 12 TDs

Love had a 52-yard touchdown run in last week's loss to Washington State, but he was held to just 69 rushing yards in the entire game. That came after he sat out Stanford's ugly win over Oregon State with an ankle injury. Love was never going to keep up the absurd big-play pace he started the season with, but he hasn't had a big game since Oct. 14 and he's playing for a three-loss Stanford team. Still, his numbers remain amazing: 9.6 yards per rush and 19 runs of 30-plus yards. He's been a spectacular home-run hitter, and based on what he's accomplished so far this season, he deserves a spot in New York. But with Stanford fading from the national picture, Love's candidacy depends on having big performances in the Cardinal's two remaining spotlight games against playoff contenders: Friday vs. Washington and Nov. 25 vs. Notre Dame.

Mason Rudolph, QB, Oklahoma State

63.3 percent, 3,314 yards, 27 TDs, 7 INTs, 170.4 rating, 10.0 YPA
7 rushing TDs

Rudolph seriously pushing for the Heisman depended on out-dueling Mayfield in Bedlam. He threw for 448 yards and led Oklahoma State to 52 points … but Mayfield threw for 150 more yards and led the Sooners to 62 points. Now, Rudolph being a candidate depends on Oklahoma State winning out, earning a Big 12 title game spot and perhaps winning a rematch with Mayfield and the Sooners (or TCU). Rudolph's numbers are fantastic, but Oklahoma State lost its two biggest games and he's the second-best quarterback in his state.

Khalil Tate, QB, Arizona

61.2 percent for 930 yards, 8 TDs, 5 INTs, 157.7 rating, 9.5 YPA
95 carries for 1,087 yards and 9 TDs

Tate already faced an uphill battle, given that he didn't start a game until October and given that few people actually watched his games late at night on Pac-12 Network. But he miraculously worked his way into the conversation with an absurd October in which he rushed for 840 yards in four straight Arizona wins, including 327 against Colorado. Despite being the primary quarterback for only five games, Tate is 12th nationally in rushing and has 14 rushes of 30-plus yards, more than anybody but Love. Tate's darkhorse hopes likely faded late last Saturday night, when he was intercepted twice to end a second-half comeback attempt against USC. He should put up huge numbers down the stretch against Oregon State, Oregon and Arizona State, but it won't be enough to land atop many ballots.

Jonathan Taylor, RB, Wisconsin

190 carries for 1,368 yards, 12 TDs

Taylor's problem is the same as Wisconsin's playoff race problem: The Badgers haven't played in big games. Wisconsin is undefeated, but the freshman Taylor entered this season as an unknown, and he's been overshadowed by Barkley in the Big Ten despite leading the conference in rushing by a wide margin and cracking 200 yards three times. Taylor's biggest opportunities for national recognition are ahead: games against Iowa and Michigan the next two weeks, plus either Ohio State or Michigan State in the Big Ten championship. If Wisconsin wins out and makes a playoff push, Taylor will vault into the conversation as the face of an undefeated team.

Sleepers/Last-Minute Long Shots

They're not contenders right now, and they probably won't be. But if everything breaks right in the next four weeks …

Jalen Hurts, QB, Alabama

60.6 percent for 1,406 yards, 10 TDs, 1 INT, 145.8 rating, 8.0 YPA
98 carries for 616 yards, 7 TDs

Defensive back Minkah Fitzpatrick is widely viewed as Alabama's best player, so he has some sleeper potential, too, but he doesn't have the numbers that a defensive player typically needs to be seriously considered. So let's mention Alabama's widely known quarterback: Hurts doesn't throw enough to earn Heisman consideration -- although he averages 2.7 more passes per game than Georgia QB Jake Fromm -- but there's always a chance that he makes big plays as both a runner and thrower in Alabama's biggest games down the stretch against Mississippi State, Auburn and Georgia. If other candidates continue to fade and Hurts saves his best for last for an undefeated, SEC champion Alabama, there's a chance for him to appear on ballots.

Kerryon Johnson, RB, Auburn

166 carries for 868 yards and 15 TDs

Again, let's emphasize the term long shot. So why is Johnson mentioned? He has played well, with several big performances in SEC games as Auburn deals with an injury to Kamryn Pettway. Mostly, it's because Auburn plays No. 1 Georgia and No. 2 Alabama in the final three weeks. If Auburn somehow beat both, it would likely be because of Heisman-conversation-worthy performances from Johnson or QB Jarrett Stidham. Remember, Tre Mason emerged from nowhere to become a finalist when Auburn made its miracle run to the national title game in 2013, with miracle wins over Georgia and Alabama.

Ronald Jones II, RB, USC

159 carries for 1,082 yards and 13 TDs

Jones has been a better player than his quarterback, Darnold, who was the preseason favorite to win the Heisman and be the No. 1 pick. Darnold is still having a strong season, but he's been too inconsistent and USC faded from the playoff race after losing to Washington State and Notre Dame. Keep an eye on Jones, though, as the underrated first-round talent who rushed for 216 against Arizona State and 194 against Arizona the past two weeks. If he continues this strong late-season push and has an impressive Pac-12 title game for a USC team that creeps back into the top 10, he could get some late attention.

McKenzie Milton, QB, UCF

70 percent, 2,409 yards, 20 TDs, 5 INTs, 189.1 rating, 11.1 YPA
55 carries for 298 yards and 3 TDs

Many people may not have noticed, but there's a quarterback for an undefeated team who averages 11.1 yards per pass attempt and has completed 70 percent of his passes. Milton has made astonishing strides from his freshman season to now, as has UCF as a whole in Scott Frost's second season. The Knights are 8-0 and average 48.5 points per game, and they are the favorite to land the Group of Five's New Year's Six bowl spot.

Rashaad Penny, RB, San Diego State

229 carries for 1,602 yards and 15 TDs
17 catches for 136 yards and 2 TDs
1 kick return TD

Losses to Boise State and Fresno State in which he was contained put an end to Penny's sleeper Heisman talk, but he's still having a phenomenal season. In replacing 2,000-yard rusher Donnel Pumphrey, Penny is on track for 2,000 yards himself. He's rebounded from those two losses by burning Hawaii for 253 yards and San Jose State for 234 yards the past two weeks. He has overtaken Barkley for the national lead in all-purpose yards per game.

James Washington, WR, Oklahoma State

52 catches for 1,133 yards and 9 TDs

Washington isn't going to overtake his quarterback, Rudolph, but he averages 21.8 yards per catch, is widely regarded as the nation's top receiver and is a big-play machine. He is, unfortunately, dealing with an ankle injury now, but if he has a strong finish to the season and the race for second and third is wide-open, perhaps he could copy Oklahoma rival Dede Westbrook's trip to New York last year.

* * *
Contact Matt at matt.brown5082@gmail.com and follow him on Twitter @MattBrownCFB and Facebook.