When the regular season ends after the first Sunday in October (or the last Sunday in September), ten teams enter the postseason playoffs. These ten teams consist of six teams that are division champions by earning the best regular-season overall win-loss record for their respective divisions, and four who are "wild-card" teams that are each one of two teams in their respective leagues who have earned the best regular season win-loss record but are not division champions. Four rounds of series of games are played to determine the champion: