The 1966 NFL season was the 47th regular season of the National Football League, and the season after which was played Super Bowl I, though it was called the AFL-NFL World Championship Game. The league expanded to 15 teams with the addition of the Atlanta Falcons, thus an odd number of teams (making byes necessary). This was the last season that NFL teams were divided into just two groups called conferences, and only one round of playoffs was played, the NFL championship game between the two conference champions.