The Serie A (Italian pronunciation: ), officially known as Serie A enilive in Italy and Serie A Made in Italy abroad for sponsorship reasons, is a professional league competition for football clubs located at the top of the Italian football league system. The winners are awarded the Coppa Campioni d'Italia trophy and the scudetto, a decoration that they wear on the jersey the season after the victory. It has been operating as a round-robin tournament for over ninety years since the 1929–30 season. It had been organized by the Direttorio Divisioni Superiori until 1943, the Lega Calcio until 2010, and the Lega Serie A ever since. Serie A is regarded as one of the best football leagues in the world and it is often depicted as the most tactical and defensively sound national league. Serie A was ranked the world's best national league in 2023 by IFFHS, and is ranked second among European leagues according to UEFA's league coefficient – behind the Premier League, and ahead of La Liga, Bundesliga and Ligue 1 – which is based on the performance of Italian clubs in the Champions League and the Europa League during the previous five years. Serie A led the UEFA ranking from 1986 to 1988 and from 1990 to 1999. In its current format, the Italian Football Championship was revised from having regional and interregional rounds, to a single-tier league from the 1929–30 season onwards. The championship titles won before 1929 are officially recognised by FIGC with the same weighting as titles that were subsequently awarded. Similarly, the 1945–46 season, when the round-robin was suspended and the league was played over two geographical groups due to the ravages of World War II, is not statistically considered, even if its title is fully official. The league hosts three of the world's most famous clubs as Juventus, AC Milan and Inter Milan, all founding members of the G-14, a group which represented the largest and most prestigious European football clubs from 2000 to 2008, with the first two also being founding members of its successive organisation, European Club Association (ECA). More players have won the Ballon d'Or award while playing at a Serie A club than any league in the world other than Spain's La Liga. Juventus, Italy's most successful club of the 20th century and the most winning Italian team, is tied for sixth in Europe and twelfth in the world with the most official international titles with eleven. Prior the first Europa Conference League final in 2022, it was also the only one in the world to have won all the historical five official confederation competitions, an achievement reached after its triumph in the 1985 Intercontinental Cup and revalidated after winning a sixth tournament, the UEFA Intertoto Cup, fourteen years later. Milan is joint third club overall for official international titles won with nineteen. Inter, following their achievements in the 2009–10 season, became the first Italian team to have achieved a seasonal treble. It is also the team to have competed uninterruptedly for the most time in the top flight of Italian football, having seen its debut in 1909. All these clubs, along with Lazio, Fiorentina, Roma and Napoli, are known as the "seven sisters" (sette sorelle) of Italian football. Serie A is one of the most storied football leagues in the world. Of the 100 greatest footballers in history chosen by FourFourTwo in 2017, 42 players have played in Serie A, more than any other league in the world. Juventus is the team that has produced the most World Cup champions (27), with Inter (20), Roma (16) and Milan (10), being respectively third, fourth and ninth in that ranking.