The National Basketball Association (NBA) (formerly Basketball Association of America (BAA) from 1946–49) Finals is the championship series for the NBA and the conclusion of the sport's postseason. All Finals have been played in a best-of-seven format, and contested between the winners of the Eastern Conference and the Western Conference (formerly Divisions before 1970), except in in which the Eastern Division champion faced the winner between the Western and Central Division champions. Prior to 1949, the playoffs were instituted a three-stage tournament where the two semifinal winners played each other in the finals. The winning team of the series receives the Larry O'Brien Championship Trophy.