The National Football League divided its teams into divisions in 1933 and began holding a single playoff championship game between division winners. In 1967, the NFL expanded and created four divisions, which led to the institution of a larger playoff tournament. After the merger with the American Football League, the NFL began to use a single wild card team in each conference in its playoffs, in order to produce eight contenders out of six divisions; this was later expanded so that more wild card teams could participate.
