The National Football League champions, prior to the merger between the National Football League (NFL) and American Football League (AFL) in 1970, were determined by two different systems. The National Football League was established on September 17, 1920, as the American Professional Football Association (APFA). The APFA changed its name in 1922 to the National Football League, which it has retained ever since. From 1921 to 1931, the APFA/NFL determined its champion by overall win–loss record, with no playoff games; ties were not counted in the winning percentage total. The APFA did not keep records of the 1920 season; they declared the Akron Pros, who finished the season with an 8–0–3 record, as the league's first champions by a vote of the owners. The Canton Bulldogs won two straight championships from 1922 to 1923, and the Green Bay Packers won three in a row from 1929 to 1931.