the next decade, three non-Victorian clubs gained entry: Adelaide (1991), Fremantle (1995) and the SANFL's Port Adelaide (1997), the only pre-existing club outside Victoria to join the league. In 2011 and 2012, respectively, two new non-Victorian clubs were added to the competition: Gold Coast and Greater Western Sydney. The AFL, currently with 18 member clubs, is the sport's elite competition and most powerful body. Following the emergence of the AFL, state leagues were quickly relegated to a second-tier status. The VFA merged with the former VFL reserves competition in 1998, adopting the VFL name. State of Origin also declined in importance, especially after an increasing number of player withdrawals. The AFL turned its focus to the annual International Rules Series against Ireland in 1998 before abolishing State of Origin the following year. State and territorial leagues still contest interstate matches, as do AFL Women players. Although a Tasmanian AFL bid is ongoing, the AFL's focus has been on expanding into markets outside Australian football's traditional heartlands in order to maximise its broadcast revenue. The AFL regularly schedules pre-season exhibition matches in all Australian states and territories as part of the Regional Challenge. The AFL signalled further attempts at expansion in the 2010s by hosting home-and-away matches in New Zealand, followed by China. Laws of the game Field Australian rules football playing fields have no fixed dimensions but at senior level are typically between long and wide wing-to-wing. The field, like the ball, is oval-shaped, and in Australia, cricket grounds are often used. No more than 18 players of each team (or, in AFL Women's, 16 players) are permitted to be on the field at any time. Up to four interchange (reserve) players may be swapped for those on the field at any time during the game. In Australian rules terminology, these players wait for substitution "on the bench"—an area with a row of seats on the sideline. Players must interchange through a designated interchange "gate" with strict penalties for having too many players from one team on the field. In addition, some leagues have each team designate one player as a substitute who can be used to make a single permanent exchange of players during a game. There is no offside rule nor are there set positions in the rules; unlike many other forms of football, players from both teams may disperse across the whole field before the start of