The AFC Champions League (abbreviated as ACL) is an annual continental club football competition organised by the Asian Football Confederation, and contested by Asia's top-division football clubs. It is the most prestigious club competition in Asian football, played by the national league champions (and, for some nations, one or more runners-up) of their national associations. Introduced in 1967 as the Asian Champion Club Tournament, the competition rebranded and took on its current name in 2002 as a result of the merger between the Asian Club Championship, the Asian Cup Winners' Cup and the Asian Super Cup. A total of 40 clubs compete in the round-robin group stage of the competition. Clubs from Asia's strongest national leagues receive automatic berths, with clubs from lower-ranked nations eligible to qualify via the qualifying playoffs, and they are also eligible to participate in the AFC Cup. The winner of the AFC Champions League qualifies for the FIFA Club World Cup. The most successful club in the competition is Al-Hilal with a total of four titles. They are also the reigning champions after winning their fourth title in 2021. History 1967–1972: Asian Champion Club Tournament The competition started as the Asian Champion Club Tournament, a tournament for the champions of AFC nations, and had a variety of different formats, with the inaugural tournament staged as a straight knock-out format and the following three editions consisting of a group stage. While Israeli clubs dominated the first four editions of the competition, this was partly due to the refusal of Arab clubs to play them: In 1970, Lebanese club Homenetmen refused to play Hapoel Tel Aviv in the semi-final, which was scratched with Hapoel advancing to the final. In 1971, Aliyat Al-Shorta of Iraq refused to play Maccabi Tel Aviv on three occasions: in the preliminary round (which was redrawn), in the group stage, and in the final, which was scratched with Maccabi being awarded the championship. During the award ceremony for Maccabi, Aliyat Al-Shorta players waved the Palestinian flag around the field, while the Iraqi media considered Aliyat Al-Shorta as the tournament's winners, with the team holding an open top bus parade in Baghdad. After the 1972 edition had to be cancelled by the AFC for various reasons, including two Arab clubs being excluded for refusing to commit to playing against Israeli club Maccabi Netanya, the AFC suspended the competition for 14 years, while Israel would