In 1924, the National Football League (originally the American Professional Football Association) decided that its season would begin on Sept 27 and end on Nov. 30, and that the championship would be based on the best winning percentage of all games played between league teams within that time period. Only wins and losses counted; a tie was simply ignored, as if the game had never been played.
That led to an odd situation in 1932, when the Green Bay Packers won 10 of their 14 games, but lost 3 and tied 1. The Chicago Bears had a 6-1-6 record and the Portsmouth Spartans were 6-1-4. Under today's system, in which a tie counts as half a win and half a loss, the Packers would have had their fourth straight championship. But with tie games left out of the formula, the Bears and Portsmouth were tied for first place with .857 winning percentages and the Packers were third .769.
The result was the first playoff game, and probably the strangest game of any kind, in NFL history. Scheduled for Dec. 18 Comiskey Park, the Bears' home field, the playoff had to be moved indoors, to Chicago Stadium, because of heavy snow. The field was only 80 yards long-60 yards from goal line to goal line-and 45 yards wide.
The Bears won the game, 9-0. Much more important, there was so much public interest in a post-season championship that the league decided to have one every year. For the 1933 season, the NFL was reorganized into the East and West Divisions, each with its own champion, and a post-season game to determine the league champion.
That simple but effective playoff system remained in place until 1967, when the NFL expanded to 16 teams and realigned into four divisions, two in each conference. That required playoffs between division champions to determine the conference championships.
The American Football League, founded in 1960, used the NFL's format for its first nine seasons, with two divisions and a league championship game between the division champions. In 1969, the last year of its existence, the AFL instituted a four-team playoff. In the first playoff round, the first-place team from each conference played the second-place team from the other conference, with the winners meeting for the championship.
In 1970, the AFL merged into a new, bigger NFL, made up of the American and National Football Conferences. Each conference was split into three divisions. Partly because a three-team playoff is unwieldy and partly to create more fan interest in the regular season, the NFL added something new to the playoff mix: a wild card, the team with the best record among those that finished second in their divisions.
When the NFL grew to 28 teams in 1978, a second wild-card team was added. Since 1990, there have been three wild-card teams from each conference. In 2002, when the NFL expands to 32 teams, there will be four four-team divisions in each conference, with the division champions and two wild-card teams from each conference advancing to the playoffs.
