Liga 1 is the top professional football league in Indonesia, established in 2017. It replaced the previous competition, Indonesia Super League, and features clubs from across the country. The league operates on a promotion and relegation system with Liga 2, the second tier of Indonesian football. The league consists of 18 teams that compete in a round-robin format, where each team plays home and away matches. The team with the most points at the end of the season is crowned the champion, while the bottom teams face relegation to Liga 2.