Lega Basket Serie A (English: Basket League A Series) is the first-tier level club competition in Italian professional basketball where play determines the national champion. It is organized by Lega Basket. The season consists of a home-and-away schedule of 30 games, followed by an eight-team playoff round. Quarterfinals and semifinals series are best-of-five, and the finals series is best-of-seven (in the 2012-13 season, all series are best-of-seven). The bottom two clubs are relegated, and replaced by the top team from the regular-season phase and the eight-team playoff round winner of the second-level Legadue.
The national basketball league was first organized for play in Italy in 1920. The first title was won by SEF Costanza Milano, and the team holding the record for title championships is Olimpia Milano, who have won 25 championships. Twenty different teams have won the championship since its inception. In recent years, the league has been dominated by a handful of teams:
Virtus' crosstown rivalsFortitudo (who dropped from the professional ranks in 2009); although only with two scudetti, they had an 11-year run from 1996 to 2006 in which they appeared in the championship series 10 times.
Through the 2007–08 season, 18 teams competed; however, in September 2008, two clubs, Basket Napoli (not related to the current NSB Napoli, which moved from Rieti to Naples after the 2008–09 season) and Orlandina, were forcibly relegated from the professional ranks for financial irregularities and were not replaced for the 2008–09 season. Today, 16 teams compete in the highest level of play.