Question: Who was Baker Mayfield's football coach in 2015?

Context articles: Baker Mayfield
Karl Spear
Gene Mayfield
John Frangoulis
Trevor Knight
2015 Oklahoma Sooners football team
Mark Raymond
Willie Fritz
Art Baker (coach)
Ernest T. Jones

Baker Reagan Mayfield (born April 14, 1995) is a college American football quarterback for the Oklahoma Sooners.
 Mayfield began his college football career as a walk-on player for the Texas Tech Red Raiders.
 He is notable for being the first walk-on true freshman quarterback to start a season opener at a BCS school.
 Mayfield transferred from Texas Tech to Oklahoma following alleged scholarship issues and a lack of communication with coaches.
 After sitting out the 2014 season due to NCAA transfer rules, Mayfield won the starting quarterback job in 2015 over Cody Thomas and incumbent starter Trevor Knight.
Karl E. Spear (December 15, 1910 – March 11, 1981) was an American football coach and college athletic administrator.
 He was the head football coach at Baker University in Baldwin City, Kansas.
 He held that position for 17 seasons, from 1946 until 1962.
 His coaching record at Baker was 87–61–4.
Clurel Eugene Mayfield, known as Gene Mayfield or "Father of Mojo" (January 31, 1928 – October 2, 2009), was an American football coach in Texas high schools and at West Texas A&M University.
 In May 2005, Mayfield was inducted into the Texas High School Coaches Hall of Fame.
John Frangoulis is an American football coach.
 He was the head football coach at Baker University in Baldwin City, Kansas for eight seasons, from 1996 until 2003.
 His coaching record at Baker was 45–39.
Trevor Knight (born October 3, 1993) is an American football quarterback for the Atlanta Falcons of the National Football League (NFL).
 He played college football for the Oklahoma Sooners and Texas A&M Aggies.
 After leading Oklahoma to an 8–5 record in the 2014 season, he lost the starting job in an open quarterback competition to Texas Tech transfer Baker Mayfield prior to the 2015 season.
 On January 4, 2016, it was announced that Knight would transfer to Texas A&M University.
The 2015 Oklahoma Sooners football team represented the University of Oklahoma in the 2015 NCAA Division I FBS football season, the 121st season of Sooner football.
 The team was led by two-time Walter Camp Coach of the Year Award winner, Bob Stoops, in his 17th season as head coach.
 They played their home games at Gaylord Family Oklahoma Memorial Stadium in Norman, Oklahoma.
 They were a charter member of the Big 12 Conference.
Mark Raymond is an American football coach, currently serving as the head football coach at Williams College.
 Raymond served as the head football coach at St. Lawrence University from 2010 to 2015, winning two conference titles and compiling an overall record of 31–30.
 Raymond was named Liberty League Coach of the Year following the conclusion of both the 2010 and 2015 seasons at St. Lawrence.
 Raymond was named head football coach at Williams College on February 24, 2016.
Willie Fritz (born April 2, 1960) is an American football coach and former player.
 He is the current head coach at Tulane University.
 From 2014 to 2015, he was head coach at Georgia Southern University.
 From 2010 to 2013, he was the head football coach at Sam Houston State University.
 From 1997 to 2009, Fritz served as the head football coach at the University of Central Missouri.
 From 1993 to 1996, he was the head football coach at Blinn College, a junior college in Brenham, Texas.
Art Baker (born November 30, 1929) is a former American football coach.
 He served as the head coach at Furman University (1973–1977), The Citadel, The Military College of South Carolina (1978–1982) and East Carolina University (1985–1988).
 Baker is a 1948 graduate of Edmunds High School (now Sumter High School) in Sumter, S. C. and a 1953 Presbyterian College graduate and also was a former assistant football coach there.
 Baker played football for the "Blue Hose" from 1950 to 1952, starting at halfback his last two years.
 He was a member of Mu chapter of Pi Kappa Alpha fraternity.
 Baker is a recipient of Presbyterian's Bob Waters Award.
 He was an assistant coach for Frank Howard at Clemson from 1965 to 1969.
 From 1970 to 1972, Baker was an assistant coach at Texas Tech.
 Baker succeeded Bob King at Furman for the 1973 season.
 As head coach at Furman Baker hired Dick Sheridan, Jimmy Satterfield and Bobby Johnson as assistants and all later became head coaches at Furman.
 Baker was an assistant coach in 1984 for Bobby Bowden at Florida State.
 He was Associate Athletics Director for Development and Gamecock Club Director at the University of South Carolina for 6 and a half years, retiring on June 30, 1995.
Ernest T. Jones (born January 18, 1970) is the current head coach at ASA Miami, a two-year college starting its first football season in 2015.
 He was briefly running backs coach for the University of Connecticut Huskies football team.
 He was head football coach at Alcorn State University.
 He was named the head football coach after the 2007 season and served as head coach in 2008.
 He was controversially fired from this position in December 2008.
 He returned to the University of Cincinnati as the Director of Player Services in 2009.
 For the 2010 he will be an assistant coach at the University at Buffalo under former University of Cincinnati assistant coach and now UB head football Coach Jeff Quinn.