In 1929 FIGC changed the mechanism of the championship, and created the Serie A as we know it today (1 league only with 16, 18 or 20 teams). These are the 66 teams which took part to the championships played from 1929–30 to 2016–17: Internazionale is the only team which played all the seasons following Juventus' relegation to Serie B after the 2005–2006 season.
There are 67 teams that have taken part in 87 Serie A championships in a single round that was played from the 1929–30 season until the 2020–21 season. The teams in bold compete in Serie A currently. Internazionale is the only team that has played Serie A football in every season.
This championship was disputed during the second World War and won by Vigili del Fuoco di La Spezia (V.V.F. Spezia, Spezia Firefighters). It was not recognized by the FIGC until 2002 and assigned to Spezia Calcio 1906, though Spezia's Scudetto is considered a "decoration".
This championship is not usually included in the statistics, because some of the southern sides that took part to the competition were Serie B teams, while northern Serie B teams played at the second level with the Serie C teams. Torino's scudetto is considered official.