Question: What position does Bob Diaco hold with the football team hat has the most wins and the highest winning percentage of any program over the last 50 years?

full_context: Document 1: 1981 Nebraska Cornhuskers football team: The 1981 Nebraska Cornhuskers football team represented the University of Nebraska–Lincoln in the 1981 NCAA Division I-A football season. The team was coached by Tom Osborne and played their home games in Memorial Stadium in Lincoln, Nebraska.
Document 2: Nebraska Cornhuskers men's basketball: The Nebraska Cornhuskers men's basketball team is the college basketball program representing the University of Nebraska-Lincoln in the Big Ten Conference of NCAA Division I. The program saw its first game in 1897 playing 7-on-7 basketball. The first collegiate game was against Nebraska Wesleyan University. Throughout the years, the program had 1,370 wins and 1,218 losses (.529) with 7 NCAA appearances and 16 NIT appearances. Nebraska's only major national trophy came when they won the 1996 NIT.
Document 3: 1995 Nebraska Cornhuskers football team: The 1995 Nebraska Cornhuskers football team represented the University of Nebraska–Lincoln and was the national champion of the 1995 NCAA Division I-A football season. The team was coached by Tom Osborne and played their home games in Memorial Stadium in Lincoln, Nebraska. The Cornhuskers scored 638 points (53.2 per game) while only allowing 174 (14.5 per game). Their average margin of victory was 38.6 points, and their lowest margin of victory, against Washington State, was 14 points. They are regarded by many as the greatest college football team of all time.
Document 4: Oklahoma Sooners football: The Oklahoma Sooners football program is a college football team that represents the University of Oklahoma (variously "Oklahoma" or "OU"). The team is currently a member of the Big 12 Conference, which is in Division I Football Bowl Subdivision (formerly Division I-A) of the National Collegiate Athletic Association (NCAA). The program began in 1895 and is one of the most successful programs since World War II with the most wins (606) and the highest winning percentage (.762) since 1945. The program has 7 national championships, 45 conference championships, 154 All-Americans (76 consensus), and five Heisman Trophy winners. In addition, the school has had 23 members (five coaches and 18 players) inducted into the College Football Hall of Fame and holds the record for the longest winning streak in Division I history with 47 straight victories, a record that stands to this day. Oklahoma is also the only program that has had four coaches with 100+ wins. They became the sixth NCAA FBS team to win 850 games when they defeated the Kansas Jayhawks on November 22, 2014. The Sooners play their home games at Gaylord Family Oklahoma Memorial Stadium in Norman, Oklahoma. Lincoln Riley is currently the team's head coach.
Document 5: Oklahoma Sooners football: The Oklahoma Sooners football program is a college football team that represents the University of Oklahoma (variously "Oklahoma" or "OU"). The team is currently a member of the Big 12 Conference, which is in Division I Football Bowl Subdivision (formerly Division I-A) of the National Collegiate Athletic Association (NCAA). The program began in 1895 and is one of the most successful programs since World War II with the most wins (606) and the highest winning percentage (.762) since 1945. The program has 7 national championships, 45 conference championships, 154 All-Americans (76 consensus), and five Heisman Trophy winners. In addition, the school has had 23 members (five coaches and 18 players) inducted into the College Football Hall of Fame and holds the record for the longest winning streak in Division I history with 47 straight victories, a record that stands to this day. Oklahoma is also the only program that has had four coaches with 100+ wins. They became the sixth NCAA FBS team to win 850 games when they defeated the Kansas Jayhawks on November 22, 2014. The Sooners play their home games at Gaylord Family Oklahoma Memorial Stadium in Norman, Oklahoma. Lincoln Riley is currently the team's head coach.
Document 6: Nebraska Cornhuskers football: The Nebraska Cornhuskers football team represents the University of Nebraska–Lincoln. Among the 128 Division I-A teams, Nebraska is one of ten football programs to win 800 or more games. Nebraska has more victories against Power Five opponents than any other program, as well as the third most victories all-time, behind only Michigan and Texas. Nebraska also has the most wins and the highest winning percentage of any program over the last 50 years. Two of Nebraska's national championship-winning teams, the 1971 and 1995 teams, are considered to be among the best college football has ever seen.
Document 7: Iowa Hawkeyes football: The Iowa Hawkeyes football team represents the University of Iowa in college football. The Hawkeyes compete in the West division of the Big Ten Conference. They have been a member of the Big Ten since 1899, and are currently a Division I Football Bowl Subdivision (FBS) member of the NCAA. The Hawkeyes play their home games in Iowa City, Iowa at Kinnick Stadium, with a capacity of 70,585. The Hawkeyes are currently coached by Kirk Ferentz, who is in his 19th season as the head coach and is the longest current tenured head coach in NCAA Division I FBS.
Document 8: Nebraska Cornhuskers: The Nebraska Cornhuskers (often abbreviated to Huskers) is the name given to the intercollegiate athletic teams of the University of Nebraska–Lincoln. The university is a member of the Big Ten Conference and the Cornhuskers compete in NCAA Division I, fielding 22 varsity teams in 15 sports.
Document 9: 1892 Iowa Hawkeyes football team: The 1892 Iowa Hawkeyes football team represented the University of Iowa during the 1892 college football season. The season involved many 'firsts' for the Hawkeyes. After going three years without a conference, Iowa joined the Western Interstate University Football Association, along with Nebraska, Missouri, and Kansas. But in another first, Edward A. Dalton, formerly of Princeton University, was hired as Iowa's head coach. Although he was only hired for 10 days prior to the season, he is recognized as Iowa's first head coach.
Document 10: Nebraska Cornhuskers football statistical leaders: The Nebraska Cornhuskers football statistical leaders are individual statistical leaders of the Nebraska Cornhuskers football program in various categories, including passing, rushing, receiving, total offense, defensive stats, and kicking. Within those areas, the lists identify single-game, single-season, and career leaders. The Cornhuskers represent the University of Nebraska-Lincoln in the NCAA's Big Ten.
Document 11: Dave Doeren: David William Doeren (born December 3, 1971) is an American football coach currently serving as the head football coach at North Carolina State University. He was previously the head coach at Northern Illinois University and has been an assistant at the University of Wisconsin, University of Kansas, University of Montana, and University of Southern California. He played college football at Drake University, where he also held his first assistant coaching position.
Document 12: Bob Diaco: Robert Albert Diaco (born February 19, 1973) is an American football coach and former player. He is currently the defensive coordinator at Nebraska. He previously was the head coach of the Connecticut Huskies football team. Prior to coaching at Connecticut, he has been a coach at Western Illinois, Eastern Michigan, Central Michigan, Virginia, Cincinnati, and Notre Dame. He played college football at Iowa.
Document 13: Kirk Ferentz: Kirk James Ferentz (born August 1, 1955) is the head football coach at the University of Iowa, a position he has held since the 1999 season. From 1990 to 1992, Ferentz was the head football coach at the University of Maine, where had a record of 12-21. He has also served as an assistant coach with the Cleveland Browns and Baltimore Ravens of the National Football League (NFL). Ferentz played college football as a linebacker at the University of Connecticut from 1974 to 1976.
Document 14: Tom Osborne: Thomas William Osborne (born February 23, 1937) is a former American football player, coach, college athletics administrator, and politician from Nebraska. He served as the head football coach at the University of Nebraska football team for 25 years, from 1973 to 1997. Osborne was one of the most successful coaches in American college football history, with a career record of 255–49–3, 13 conference championships, and three national championships. He was inducted into the College Football Hall of Fame as a coach in 1999. Osborne was later elected U.S. Representative from Nebraska's 3rd congressional district, as a Republican. He served three terms, from 2001 to 2007. In 2007, he returned to the University of Nebraska as athletic director (AD). He retired as AD in January 2013.
Document 15: Scott Frost: Scott Andrew Frost (born January 4, 1975) is an American football coach and former player. He is currently the head coach at the University of Central Florida (UCF). He was previously the offensive coordinator at the University of Oregon. He played six years in the National Football League with the New York Jets, Cleveland Browns, Green Bay Packers, and Tampa Bay Buccaneers. Frost was the starting quarterback for Tom Osborne's undefeated Nebraska Cornhuskers 1997 team that shared the national championship with the Michigan Wolverines.
ground_truth: defensive coordinator