were changed in 2013. Regulations The championship, in its current form, has been organized since the 1992–93 season by the Hellenic Basketball Clubs Association (HEBA), under the authority of the Hellenic Basketball Federation. The fully professional Greek basketball clubs compete in the first division championship, which is often colloquially called the "A1", in which 12 teams compete for the Greek National Championship. There is also a professional level second division championship that is run entirely by the Hellenic Basketball Federation, which is called the "A2", in which 16 teams compete for the second division crown. The bottom one place finishing team each year in the A1 division standings is relegated to the A2 division, due to poor performance. While conversely, the top one teams each year from the A2 division is promoted to the A1 division, due to good performance. Club and arena standards In order to compete in the Greek Basket League, clubs must invest a minimum of €1 million on club operations per season. The minimum club budget per season is €800,000 euros, and each club must also invest €200,000 euros into a league-wide fund that insures players get their full salaries. Most of the league's clubs invest more than the minimum requirements in each season. Currently, Greek Basket League clubs must play their home games in arenas with a seating capacity of at least 2,000 people, in order to play Greek domestic league games. Several Greek clubs have two arenas that they primarily use. One for domestic Greek League games, and one for European-wide games. Greek clubs that play in European-wide competitions, such as the EuroLeague, the EuroCup, or the FIBA Champions League, must play their home games in those leagues in arenas that fit the arena standards of those leagues. Which are currently, a 5,000 seat minimum for the EuroLeague, and a 3,000 seat minimum for the EuroCup and FIBA Champions League. Although the FIBA Champions League's minimum seat rule can be waived with the league's approval. Foreign players Greek Basket League teams were first allowed to have foreign (non-Greek) players on their rosters in the 1988–89 season. Under the league's current foreign player rules, Greek Basket League teams must have at least 6 Greek players on their active 12 man game rosters. Each team is allowed to have up to 6 foreign (non-Greek) players, on their active 12 man game roster. There are no restrictions