The Brazilian Football League

The Série A (informally called Brasileirão) is the main division of Brazilian football. It is presently composed of 20 teams; currently, the bottom four teams in Série A are relegated and the top four teams in Série B are promoted.

Since 2003, the Série A has been contested in a double round-robin format. In other words, each team plays against each other home and away, and the team with most points is declared champion. There is no final match, which is a very controversial subject. Prior to 2003, the Brazilian championship has traditionally been decided with some type of playoff format (most commonly the "Octagonal", where the top 8 regular season teams comprise a single elimination tournament), rather than the European model of points accumulated over a season. Although some purists complain that this system lacks the drama of playoffs and finals, the championship has so far shown to be well balanced, without the limited number of clubs dominating the league as found in many European leagues.

The seasons with more entrants were: 2000 (116 entrants), 1979 (94 entrants) and 1986 (80 entrants).

All the big clubs from São Paulo, except Palmeiras, withdrew from the 1979 championship. They protested against the odd system of tier qualification which made rivals Palmeiras and Guarani, previous-year finalists, enter only in final phase, and asked for the same privileges. Indeed oddly enough, Guarani finished in the top 12 playing only 3 games, probably a world record especially in a championship with 96 entrants. Palmeiras itself finished third despite playing only 5 games.

In 1984, Juventus, a small club from São Paulo, managed to qualify for the Série A. That year participants could be promoted and relegated from and to Série B in the middle of the tournament. Juventus started thus the tournament in the premiership, was relegated in the middle of the tournament but eventually managed to clinch te Série B title. Despite this the team was not promoted the year after to Série A and failed to qualify to it from the state championship.

In 1999, an averaging relegation system similar to the one used in the Primera División Argentina was adopted. The two clubs with the worst point results in the first stage of the two previous seasons were to be relegated. However, this system only lasted for a single season.

In 2005, each team played 42 games, 21 home and 21 away, for a total of 462 games. The champion and runner-up automatically qualified for the 2006 Copa Libertadores. The third and fourth placed teams may also represent Brazil in the Libertadores by defeating foreign clubs to be determined by CONMEBOL in pre-tournament trials. The champion and 5th through 11th placed teams also win the right to represent Brazil in the Copa Sudamericana, another South American championship of lower stature. The four last ranked teams (19th, 20th, 21st and 22nd) were relegated to the following year's Série B.

Eleven matches of the 2005 competition were annulled due to a match-fixing scandal and had to be replayed.

For the 2006 season, the number of contestants was reduced to 20, and CBF claims it to be the "definitive" format. In 2006, the limit on the number of foreign players was that no team can have more than 3 foreign players on the field or on the bench in a single match.