The National Lacrosse League (NLL) is a men's professional box lacrosse league in North America. The league is headquartered in Philadelphia, Pennsylvania. The NLL currently has fifteen teams: ten in the United States and five in Canada. The NLL ranks third in average attendance for pro indoor sports worldwide, behind only the NHL and NBA. Unlike other box lacrosse leagues which play in the summer, the NLL plays its games in the winter and spring, from December to June. Each year, the playoff teams battle for the National Lacrosse League Cup. The NLL has averaged between 8,900 and 10,700 spectators per game each year since 2004.