Beginning with the 1933 season, the NFL featured a championship game, played between the winners of its two divisions.
In this era, if there was a tie for first place in the division at the end of the regular season, a one-game playoff was used to determine the team that would represent their division in the NFL Championship Game.
1967 was the first year where a pre-scheduled playoff (rather than regular season results) determined participation in the championship.
In 1982, the league held a 16-team tournament due to the players strike, which reduced the regular season to just 9 games.
Starting with the 1970 merger with the American Football League the NFL expanded its playoffs to 8 teams total.