University of Oklahoma quarterback Baker Mayfield has won the 2017 Heisman Trophy, college football’s top individual prize. Mayfield had been a Heisman Trophy top-five finalist each of the past two season as well, and he becomes the sixth Sooner to win the award.

He expressed gratitude for the OU community at large.

“Everybody at OU. Staff welcoming me with open arms. It’s been the greatest thing that’s ever happened to me. I can’t thank everybody enough,” Mayfield said after receiving the trophy. “There’s a standard and tradition there that’s set very high, and I wouldn’t have it any other way.”

Mayfield thanked his family, teammates and coaches.

“Coach Stoops, you welcomed a chubby, unathletic kid into the program with open arms,” Mayfield said to Bob Stoops, former OU head coach. “The thing I’m most thankful for is (you) hiring Coach Riley.”

Mayfield addressed Riley directly.

“You’ve been a great mentor to me. We’ve been through a lot together,” he said.

He concluded his speech with advice for children who might be watching.

“To the kids out there. Don’t give up. Don’t ever give up.”

From walk-on to Heisman Trophy winner

A former walk-on at Texas Tech University, Mayfield joined the Sooners for the 2014 season, also as a walk-on. A controversial rule forced him to lose a year of eligibility while sitting out that season as a transfer within the Big 12 Conference. But the conference ultimately changed the rule and Mayfield was granted a fourth year of eligibility, which he has put to use with record efficiency.

With OU set to play Georgia in a national semifinal matchup Jan. 1, Mayfield has already established career highs this season in yards (4,340), passing touchdowns (41), yards-per-attempt (11.8) and QB rating (203.8). He trails only Oklahoma State University quarterback Mason Rudolph for the national lead in passing yards (4,553), and his QB rating is 19 points higher than the next closest player, McKenzie Milton of the University of Central Florida.

He already holds the single-season QB rating record for his 196.39 mark in 2016. He finished third in voting for the Heisman Trophy that year behind electrifying Houston Texans rookie QB Deshaun Watson (Clemson) and the 2016 winner, Louisville’s Lamar Jackson.

Mayfield joins former OU Sooners Billy Vessels (1952), Steve Owens (1969), Billy Sims (1978), Jason White (2003) and Sam Bradford (2008) as Heisman Trophy winners.

He has faced criticism for on-field and off-field actions this year. Before the season began, Mayfield was arrested in Arkansas for attempting to evade a police officer after a fight at a club.

After an early-season victory over highly ranked Ohio State, Mayfield planted the OU flag at midfield in Columbus, Ohio. During a road game at the University of Kansas, Mayfield was caught on camera cussing at KU players and gesturing with his crotch. He was suspended for one series in his final home OU game against West Virginia.

Thursday, Mayfield won two other major college football awards: The Davey O’Brien Award for the nation’s top quarterback and the Maxwell Award for the top overall player.

He is the first Heisman Trophy winner who started his collegiate career as a walk-on.

Mayfield mentions Mackenzie Asher

Asked a series of interview questions during Saturday night’s Heisman presentation television show, Mayfield noted inspiration he has taken from Mackenzie Asher, a child who became close to the OU football program while battling leukemia.

“She’s a girl that (had) the biggest heart I’ve ever met,” Mayfield said. “She really showed not to take anything for granted.”

Mayfield said Asher died days earlier at age 11.

“I didn’t make her day, she made mine,” Mayfield said of Asher.

(Update: This post was updated at 8:09 p.m., Saturday, Dec. 9, 2017, to include comments from Mayfield’s post-ceremony speech.)