The NCAA was without a playoff for the major college football teams in the University Division, later known as Division I-A, during the 20th century. The NCAA recognizes Division I-A national champions based on the final results of polls including the "wire service", FWAA and NFF. The 1964 AP poll continued to rank only ten teams, compiling the votes of 55 sportswriters, each of whom would give their opinion of the ten best. Under a point system of 10 points for first place, 9 for second, etc., the "overall" ranking was determined.
The 1980 NCAA Division I-A football season saw a university from the state of Georgia take its first national title since 1942.
The 1958 NCAA University Division football season was notable in that it was the first to feature the two-point conversion. On January 13, 1958, the eleven-man NCAA Rules Committee unanimously approved a resolution to allow teams to choose between kicking an extra point after a touchdown, or running or passing from the three-yard line for two points. University of Michigan athletic director Fritz Crisler said at the meeting in Fort Lauderdale, "It's a progressive step which will make football more interesting for the spectators," adding that the rule "will add drama to what has been the dullest, most stupid play in the game."
The 1957 NCAA University Division football season saw two different national champions. Auburn was ranked first in the AP writers' poll taken at season's end, while Ohio State was first in the UPI coaches' poll. Auburn was ineligible for a bowl game, however, having been placed on probation indefinitely by the Southeastern Conference, after having paid two high school players $500 apiece.
The 1973 NCAA Division I football season was the first for the NCAA's current three-division structure. Effective with the 1973–74 academic year, schools formerly in the NCAA "University Division" were classified as Division I. Schools in the former "College Division" were classified into Division II, which allowed fewer athletic scholarships than Division I, and Division III, in which athletic scholarships were prohibited.
The 1929 college football season saw a number of unbeaten and untied teams. Purdue, Tulane, Notre Dame, and Pittsburgh all finished the regular season with wins over all their opponents. Notre Dame was recognized as national champion by two of three contemporary major selectors, while the third (Houlgate) named USC (10–2). Eight of nine retrospective selectors later also named Notre Dame and USC as No. 1 teams.
The 1944 college football season was the 76th season of intercollegiate football in the United States. Competition included schools from the Big Ten Conference, the Pacific Coast Conference (PCC), the Southeastern Conference (SEC), the Big Six Conference, the Southern Conference, the Southwestern Conference, and numerous smaller conferences and independent programs.
The 1955 college football season saw the Oklahoma Sooners win the national championship after going 10–0–0. Although the final poll was taken before the postseason bowl games, Oklahoma played against the nation's other unbeaten and untied (10–0–0) team, the Maryland Terrapins, at the Orange Bowl in Miami, and won 20–6.
The 1954 college football season saw three teams finish unbeaten and untied, with Ohio State Buckeyes and the UCLA Bruins sharing the national championship as the No. 1 picks of the AP Poll and the UPI Poll, respectively. Although the winners of the Big Ten and the Pacific conferences normally met in the Rose Bowl, a "no repeat" rule prevented the two champions from meeting. UCLA, which had been in the Rose Bowl earlier in the year, was replaced by conference runner-up USC.
The 1953 college football season was marked by the surprising abandonment of the two-platoon system and unlimited substitution by the NCAA rules committee in January in favor of the historic one-platoon system with its highly restrictive substitution rules. This radical rules shift made the 1953 season "The Year of the Great Adjustment," in the words of sportswriter Tommy Devine of the Detroit Free Press, in which teams scrambled to tighten their rosters and alter their strategies in accord with the more conservative "iron man" game.
The 1952 college football season ended with the unbeaten Michigan State Spartans (9–0) and Georgia Tech Yellow Jackets (12–0) each claiming a national championship from different polls. Michigan State finished first according to two of the "wire service" polls, which both placed Georgia Tech second. Georgia Tech was first in the International News Service poll. UP and INS merged in 1958 to form UPI.
The 1950 college football season finished with the unbeaten and untied Oklahoma Sooners (9–0) being the consensus choice for national champion. On New Year's Day, however, the Sooners were upset by the Kentucky Wildcats in the Sugar Bowl. The Army Cadets, ranked No. 2 in the AP Poll, had been defeated in their final regular season game by 2–6 Navy, 14–2. However, the final poll had been issued on November 27, and the bowl games had no effect on Oklahoma's status as the No. 1 team.
The 1948 college football season finished with SMU halfback Doak Walker as the Heisman Trophy winner and six teams in contention for the national championship:
- Bennie Oosterbaan's Michigan compiled a 9–0 record, defeated six ranked opponents, and was the consensus national champion, receiving 192 of 333 first-place votes in the final AP Poll. It was Michigan's second consecutive undefeated season, extending the program's winning streak to 23 games.
- Frank Leahy's Notre Dame Fighting Irish compiled a 9–0–1 record and had a 21-game winning streak dating back to the 1946 season before playing a 14–14 tie with USC in the final game of the 1948 season. Notre Dame was ranked No. 2 in the final AP Poll, receiving 97 of 333 first-place votes.
- Carl Snavely's No. 3 North Carolina Tar Heels, led by Heisman Trophy runner-up Charlie Justice, were undefeated in the regular season (9–0–1) but lost to Oklahoma in the 1949 Sugar Bowl.
- Pappy Waldorf's No. 4 California Golden Bears, led by Jackie Jensen who finished fourth in the 1948 Heisman Troophy voting, were undefeated in the regular season (10–0), but lost to Northwestern in the 1949 Rose Bowl.
- Bud Wilkinson's No. 5 Oklahoma Sooners compiled a 10–1 record, including a victory over No. 3 North Carolina in the 1949 Sugar Bowl.
- Earl Blaik's No. 6 Army Cadets finished the season undefeated (8–0–1). They won the first eight games of the season and were ranked No. 3 in the AP Poll before playing Navy to a tie in the annual Army–Navy Game.
The 1947 college football season finished with Notre Dame, Michigan, and Penn State all unbeaten and untied, but the Fighting Irish of Notre Dame were the first place choice for 107 of the 142 voters in the final AP Poll in early December, and repeated as national champions. Michigan was selected for the top spot by six contemporary math systems.
The 1946 college football season was the 78th season of intercollegiate football in the United States. Competition included schools from the Big Ten Conference, the Pacific Coast Conference (PCC), the Southeastern Conference (SEC), the Big Six Conference, the Southern Conference, the Southwestern Conference, and numerous smaller conferences and independent programs. The season saw the return of many programs which had suspended play during World War II, and also the enrollment of many veterans returning from the war.
The 1937 college football season ended with the Panthers of the University of Pittsburgh being named the nation's No. 1 team by 30 of the 33 voters in the Associated Press writers' poll. The AP poll was in its second year, and seven votes were taken during the final weeks of the 1937 season, starting with October 18. Each writer listed his choice for the top ten teams, and points were tallied based on 10 for first place, 9 for second, etc., and the AP then ranked the twenty teams with the highest number of points. With 33 writers polled, Pitt received 30 first place votes and 3 second-place, for a total of 327 points.
The 1938 college football season ended with the Horned Frogs of Texas Christian University (TCU) being named the nation's No. 1 team by 55 of the 77 voters in the final Associated Press writers' poll in early December. Tennessee was also chosen by six contemporary math system selectors as a national champion; both teams won every game. Notre Dame was chosen by the Dickinson System and won the Knute Rockne Memorial Trophy.
The 1939 college football season concluded with the Aggies of The Agricultural and Mechanical College of Texas being named as the national champions by the voters in the Associated Press writers' poll. Led by consensus All-American fullback John Kimbrough, the Aggies went undefeated at 11–0 and outscored their opponents by a combined total of 212 to 31, with the defense allowing just 54 first downs and 763 yards all season, or 1.71 yards per play. On New Year's Day, Texas A&M defeated Tulane, 14–13 in the Sugar Bowl.
The 1941 college football regular season was the 73rd season of intercollegiate football in the United States. Competition included schools from the Big Ten Conference, the Pacific Coast Conference (PCC), the Southeastern Conference (SEC), the Big Six Conference, the Southern Conference, the Southwestern Conference, and numerous smaller conferences and independent programs.
The 1945 college football season was the 77th season of intercollegiate football in the United States. Competition included schools from the Big Ten Conference, the Pacific Coast Conference (PCC), the Southeastern Conference (SEC), the Big Six Conference, the Southern Conference, the Southwest Conference, and numerous smaller conferences and independent programs. The season followed the end of World War II in August 1945, though many college players remained in military service.