List of NFL seasons
The National Football League is a professional American football league in the United States and the highest professional level of American football in the world. It was formed in 1920 as the American Professional Football Association before adopting its current name for the 1922 season. After initially determining champions through end-of-season standings, a playoff system was implemented in 1933 that culminated with the NFL Championship Game. Following an agreement to merge the NFL with the rival American Football League in 1966, the Super Bowl was first held in 1967 to determine a champion between the best teams from the two leagues and has remained as the final game of each NFL season since the merger was completed in 1970. After the merger, all AFL Championship Games and records were included in NFL record books, and the teams have been divided between the American Football Conference and the National Football Conference.
Since 2002, the league has consisted of 32 teams based across the United States. Each NFL season since 2021 has started with a three-week preseason in August, followed by the 18-week regular season which runs from early September to early January, with each team playing 17 games and having one bye week. Following the conclusion of the regular season, seven teams from each conference advance to the playoffs, a single-elimination tournament that culminates in the Super Bowl, which is contested in February and is played between the AFC and NFC conference champions.
Early years (1920–1932)
Early championships between 1920 and 1932 were awarded to the team with the best won-lost record, initially rather haphazardly, as some teams played more or fewer games than others, or scheduled games against non-league, amateur or collegiate teams; this led to the 1920 title being determined during a league meeting after the season, the 1921 title being decided on a controversial tiebreaker, a disputed 1925 title, and the scheduling of an impromptu 1932 indoor playoff game.| Season | No. of teams | Champion | Ref. |
| 1920 | 14 | Akron Pros | |
| 1921 | 21 | Chicago Staleys | |
| 1922 | 18 | Canton Bulldogs | |
| 1923 | 20 | Canton Bulldogs | |
| 1924 | 18 | Cleveland Bulldogs | |
| 1925 | 20 | Chicago Cardinals | |
| 1926 | 22 | Frankford Yellow Jackets | |
| 1927 | 12 | New York Giants | |
| 1928 | 10 | Providence Steam Roller | |
| 1929 | 12 | Green Bay Packers | |
| 1930 | 11 | Green Bay Packers | |
| 1931 | 10 | Green Bay Packers | |
| 1932 | 8 | Chicago Bears |