He obviously didn't know it at the time, but when Oklahoma football coach Bob Stoops agreed to take in walk-on transfer Baker Mayfield in the spring of 2014, he potentially might have inherited the program's sixth Heisman Trophy winner.

Mayfield first approached Stoops about joining the Sooners following a team meeting at spring practice almost two years ago. “I went up and shook his hand and said, 'Coach, I'm Baker Mayfield .' He looked at me like, 'He really is here,'” Mayfield recalled. “People probably thought I was crazy just showing up without talking to the coaches. It kind of was crazy.”

Stoops described the chain of events with Mayfield as “Maybe the strangest thing that has ever happened in my coaching career. I was hearing the rumors that he was transferring to Oklahoma. I've never talked to the guy. He's never called to ask if he could.”

After earning the starting role as a walk-on freshman quarterback at Texas Tech, Mayfield left the Red Raiders in early December 2013 because of uncertainty as to whether he would be placed on scholarship.

He opts not to slide or run out of bounds despite it being in the best interest of safety. Instead, Mayfield squeezes out as many yards as possible, plus a few more yards that didn't seem possible.

Even with Mayfield's impressive showing at Texas Tech that resulted in him being named Big 12 Offensive Freshman of the Year, it was still a courageous move to show up unsolicited at OU. “If I said no (to joining the team), he might be in a fraternity playing yard ball,” Stoops said.

In late September 2014, the NCAA denied Mayfield's appeal for immediate eligibility with the Sooners, but OU was granted a waiver to exceed the 85-scholarship limitation by one. Mayfield was placed on scholarship the next day, but he had to sit out last season due to NCAA transfer rules.

Mayfield had chosen to compete for a starting spot against Trevor Knight , a redshirt freshman who had just been named MVP of the Sugar Bowl after throwing for 348 yards and four touchdowns in a 45-31 upset over two-time defending national champion Alabama.

For someone who received scholarship offers out of high school from only five FBS programs (Army, Florida Atlantic, New Mexico, Rice and Washington State), Mayfield certainly could have chosen a path of less resistance, but he has long loved the Sooners even though he grew up in Austin, Texas.

The 6-foot-1, 209-pound Mayfield also enjoys a challenge, perhaps a bit too much. It's an admirable trait that's easily visible with nearly every snap from center this season.

We've seen it many times: Mayfield drops back looking to pass; steps up in the pocket; avoids the pass rush; still looking; steps out; slips a tackle, and another, and another; scrambles some more; reverses field; then finally tucks the ball and takes off running. He opts not to slide or run out of bounds despite it being in the best interest of safety. Instead, Mayfield squeezes out as many yards as possible, plus a few more yards that didn't seem possible.

Mayfield's bull-headed refusal to go down when pressured has caused defenses fits all season.

A recent example: On a third-and-27 in the first quarter of the Sooners' 44-34 upset victory at Baylor, Mayfield dropped back to pass, zig-zagged approximately 35 yards and wound up gaining only 2, refusing to go down despite having multiple opportunities to do so.

Mayfield smiled when he recalled the play. “At the end of it, I saw a light right there,” Mayfield said of escaping a horde of defenders. “I almost slipped out of it. If I had slipped out of one tackle, it probably would have been a very big play. Plays like that, it's either get some yards or get the ball out of my hand.”

Later that same game, with less than five minutes remaining and OU clinging to a 37-34 lead, a scrambling Mayfield extended a pass play long enough for fullback Dimitri Flowers to release and find a seam in the end zone, where Mayfield fired a game-clinching 7-yard touchdown strike.

Consider it a Heisman moment for a player who was not on anyone's Heisman watch lists. After not receiving a single vote in ESPN's Heisman watch list the previous week, Mayfield catapulted to No. 2 behind Alabama running back Derrick Henry two weeks ago.

Perhaps an even more indelible Heisman moment for Mayfield came in a 58-23 victory over Oklahoma State in Stillwater that clinched the Sooners' ninth Big 12 championship.

When redshirt freshman running back Joe Mixon was stopped cold on a run off left tackle, he improvised and reversed field. An alert Mayfield threw a key block that sprung Mixon for a 66-yard touchdown run. After making the block, Mayfield began sprinting downfield directly behind Mixon as if he was trying to catch the speedster. It appears Mayfield's goal is to be the first to congratulate whoever scores a touchdown for the Sooners, and such was the case with Mixon in Bedlam.

WATCH: Joe Mixon spun away from a would-be tackler and sprinted 66 yards, sprung by a block from Baker Mayfield , to put the Sooners up 21-10 in their Big 12 Championship-sealing game against Oklahoma State.

Overlooked after Mayfield executes all these exhausting maneuvers during a scoring drive is that he sprints back to the line of scrimmage to run the next play in the Sooners' no-huddle offense, a fast-paced attack that's exhausting to watch, let alone execute. This perpetual hustle proves Mayfield and his teammates are in remarkable shape.

“Oh, yeah,” Mayfield acknowledged with a huge grin. “You can't ever show a sign of weakness, so you have to be tough.”

Tough like the time Mayfield's body was snapped backward on a horse-collar tackle by Baylor's Travon Blanchard. A contorted Mayfield slowly rose to his feet, shook off the effects and promptly led the Sooners on a 78-yard, game-clinching drive capped by the aforementioned touchdown pass to Flowers.

“It was pretty painful,” Mayfield admitted of being horse collared. “I hurt my shoulder later on that drive, but the horse collar kind of was a wake-up call. It tweaked some things … but I'm good. My lower back was a little strained, but nothing other than that.”

Since the NCAA began awarding athletic scholarships in 1950, no walk-on has ever won the Heisman Trophy.

Since the NCAA began awarding athletic scholarships in 1950, no walk-on has ever won the Heisman Trophy. This would make things doubly impressive if Mayfield were to become the first two-time walk-on to ever win sport's most prestigious individual award. With the 11-1 and No. 3-ranked Sooners almost certainly bound for the College Football Playoffs thanks in large part to Mayfield, it also seems certain Mayfield will be among the Heisman finalists to travel to New York City next week.

OU has had two Heisman-winning quarterbacks in the Stoops era (1999-present), but Jason White (2003) and Sam Bradford (2008) had the luxury of being protected by All-American receivers and offensive linemen such as Mark Clayton, Jammal Brown, Vince Carter, Duke Robinson, Jermaine Gresham, Trent Williams and Ryan Broyles.

Mayfield has a potential All-American receiver in senior Sterling Shepard , but the Sooners' offensive line has been a perpetual work in progress this season with a true freshman and redshirt freshman starting at the tackles and a true sophomore at left guard who saw only a handful of snaps last year. Though the O-line undoubtedly has improved and continues to evolve, it is nowhere near the ilk of who shared the field with White and Bradford.

All of which makes Mayfield's season even more remarkable.

Mayfield said his biggest improvement this season is his ability to make routine plays, which sounds odd coming from someone with such unique improvisational skills. “Scrambles and reaction plays are on the fly,” Mayfield admitted, “but on the routine plays, there's a lot more focus on getting the ball out of your hands and helping your team out.”

The only moves fans got to see from an inactive Mayfield last year was a “Whip” dance recorded during Russell Athletic Bowl week, a video that went viral when it was posted on YouTube nine months later. Mayfield has been sacked 37 times this season. If he didn't have all his dance moves to escape the pressure, Mayfield would have been sacked even more.

Mayfield is both mesmerizing and terrorizing, not only to opponents but also to enraptured OU fans, who cringe that their bandana-wearing savior is trying to do too much too often.

Is Mayfield courageous or just plain crazy in his refusal to surrender at any given moment on any given play?

Reality hit hard against TCU when Mayfield was forced to miss the second half after suffering a headache on a vicious helmet-to-helmet hit in the second quarter from linebacker Ty Simmons, who was ejected for targeting.

One of Mayfield's greatest contributions to the OU offense has been terminating the “Pick 6” plight that severely damaged the psyche of players, coaches and fans in recent seasons.

This is Stoops' 17th year with the Sooners. In the first 16 seasons, OU quarterbacks had an astonishing 19 interceptions returned for touchdowns. In his 31 starts with the Sooners, Bradford never threw a Pick 6. In his 12 starts at OU, Mayfield also has thrown a shutout.

Mayfield has avoided making colossal mistakes that can instantaneously flip a game upside down, and this quest for damage control is hardly by accident. One of Mayfield's first meetings with Stoops and new offensive coordinator Lincoln Riley pertained to this very subject. Mayfield's decision making and Riley's low-risk play-calling deep in OU territory have helped stem a previously disastrous tide.

“Something they both stressed during the quarterback competition (among Mayfield, Trevor Knight and Cody Thomas in the offseason) is we need to take care of the ball,” Mayfield said. “Obviously you need that from your quarterback to help your team out, but that's something we really stressed.”

The OU athletics communications department commenced with a #Baker4Heisman campaign two weeks ago that includes a creative 8-bit GIF of a dancing Mayfield and a highlight video. Heisman ballots are due Dec. 7 and the trophy presentation is Dec. 12. Many of Mayfield's teammates also have begun to lobby for him publicly.

“It's always good to see your teammates behind you like that,” said a smiling Mayfield, who vows not to let the Heisman hype become a distraction. “You can either let it (the attention) get to your head and focus on that, or you can realize the only reason you're here is because of all the hard work you and your teammates have done. I'm not trying to change anything as to my process right now.”

Mayfield's candidacy isn't a matter of him stringing together a few good weeks. His numbers have sparkled all year, which explains why he led the nation in passing efficiency much of the season and now stands third (178.9), a rating just shy of Bradford's (180.8) the year he won the award. Mayfield ranks fourth in points responsible for (252), fifth in touchdown passes (35), sixth in points responsible for per game (21.0) and eighth in completion percentage (.686). Mayfield also has thrown just five interceptions and has not lost a fumble.

If the Sooners were to win their eighth national championship this season, they would finish with a 13-1 record. That would be a Baker's Dozen, a befitting total given how frantically Mayfield has been cooking up victories this season.

No way would Mayfield have experienced this same success had he remained at Texas Tech. “It's been a weird ride,” Mayfield said. “Honestly, I wouldn't have drawn it up any different, looking back on it now. It's made me who I am today. I'm happy I'm here. I'm not sure I would have near the success if I was there. I really am happy I'm here.”

So are his teammates and coaches, and OU fans.