Ryan McGee takes a look at Baker Mayfield and how the three-time winner of the Big 12 has become the face of college football. (1:58)

Editor's note: This story was originally published in the run-up to Baker Mayfield's Heisman victory. It has been updated.

When Oklahoma quarterback Baker Mayfield was named the winner of the 83rd Heisman Trophy it was a moment that marked the culmination of one of the most improbable rises in college football history.

Mayfield didn't start the season opener of his high school junior year.

He walked on at Texas Tech.

He transferred to Oklahoma without invitation, much less a scholarship.

Yet all along the way, Mayfield defied the odds, utilizing unrivaled self-confidence and unmatched competitive spirit. Tom Herman, coach of the rival Texas Longhorns, says Mayfield is college football's "ultimate competitor."

That ubercompetitive, ultraconfident mentality, full of trash-talking, flag-planting -- and in one case, crotch-grabbing -- swagger, has ruffled Mayfield's opponents over the years.

But he has backed up his bold antics with a dazzling display of quarterbacking magic, passing for 4,340 yards and 41 touchdowns this season with just five interceptions. And having gone from an undersized, under-recruited afterthought to one of college football's greatest-ever quarterbacks, Mayfield has earned the respect and admiration of the opposition.

Told through the viewpoint of those he has competed against for wins and positions, this is Mayfield's story, from high school all the way to the Heisman ceremony.

Chris Ross remembers all too well the play that convinced him Mayfield was different from the quarterbacks he'd coached against. In the fourth round of the Texas Class 4A state playoffs, Ross and Cedar Park faced Mayfield in a rematch from the regular season. Because the teams knew each other well, the game turned into a defensive struggle. Mayfield, however, would deliver the game-turning pass Ross says he'll "never forget."

"We blitz a guy through the A-gap, and he's unblocked," said Ross, now on the staff at Boise State. "Baker sees it, slides right into the hit and throws an absolute dart, a touchdown pass, and wins the game. Our guy knocked him out of the game, too.

"How many kids are going to step up and take that hit? As the opposing coach, there's nothing else you can do. It was an unbelievable play only somebody like a Baker Mayfield could make."

AP Photo/Tony Gutierrez

That 2011 season actually began with Mayfield watching from the sideline. But on the fifth play of Lake Travis' opener, starter Collin Lagasse suffered an injury that catapulted Mayfield into the lineup against rival Westlake at Texas' Darrell K Royal-Memorial Stadium. Mayfield won that first game. Then he took Lake Travis all the way to a Texas record fifth straight state title.

In the state championship against Hewitt Midway, Mayfield delivered the play of the game, rolling out of an all-out rush to find a receiver for a 17-yard touchdown.

"Once you had it figured out, that didn't mean you'd stopped him," said Terry Gambill, Midway's coach that season, who is now at Allen. "When he got pressure, he could keep his eyes down the field and find receivers. He was good at that, even back in those days."

Above all else, Mayfield excelled at winning. In two seasons as Lake Travis' starting quarterback, Mayfield went 25-2. And according to those who had to go against him, Mayfield approached every game with a unique brazenness.

"He had that 'it factor' that you don't coach," said Aledo coach Steve Wood, who couldn't beat Mayfield even with five-star running back Johnathan Gray. "He had just cranked it up then. He wasn't fist-pumping or carrying on like he does now. But it seemed like he had a different wheel than other kids."

Despite his sterling prep record, Mayfield never became a blue-chip prospect. He was barely over 6 feet tall. And because he lacked prototypical size, the big schools in Texas all passed, most notably TCU. With few options available, Mayfield opted to walk on at Texas Tech.

Yet, while college recruiters didn't think much of him, those Mayfield had competed against in high school still saw greatness ahead.

"There's something to be said for kids that win, whether you're 5-8 or 6-8," Wood said. "And Baker Mayfield was one of those guys that was going to make his own way because people were not going to give him anything."

Before becoming his position coach, playcaller and eventually, this season, his head coach, Lincoln Riley actually attempted to dissuade Mayfield from transferring to Oklahoma.

Riley was the offensive coordinator at East Carolina. And Trevor Knight had just quarterbacked the Sooners to a Sugar Bowl win over Alabama as a freshman.

"I was using that when I was trying to recruit him," Riley said. "I was like, 'Trevor Knight is going to be the guy there for three years, are you crazy?' I told him that verbatim on the phone."

Mayfield didn't listen. And when no one else did, he still believed in himself.

"He had a passion, he had a dream," Knight said. "He went to Texas Tech, realized he was capable of playing at a high level, and he wanted to go where his heart was, his passion was. And so, he decided to go to his dream school."

Before Mayfield would challenge Knight for the starting job, he challenged Oklahoma's defense. Ineligible for a season after transferring, Mayfield ran the scout-team offense in 2014 and torched the first-team defense on an almost-daily basis.

"Scrambling forever to make a play, the things he does now, he would be doing those in practice," said Eric Striker, an All-American linebacker for Oklahoma that year. "And he liked to make you feel it. He wasn't just going to do you in, he was going to talk to you about it, too."