was watching Boca vs River PLate the other day

THIRTY TEAMS

they like Mexico, play 2 seasons, Inicial and Final

For the 2012–13 season, the Torneo Apertura and Clausura became "Torneo Inicial" and "Torneo Final," being disputed with the same format as before but proclaiming only one champion each season, unlike the last format that had two champions (Apertura and Clausura, respectively). At the end of both tournaments, the winners of Inicial and Final tournaments play a match to determine the champion of the season.

Before those changes, a controversial project for the 2012–13 season had been proposed: it consisted in a new tournament that would contain both the Primera División and Primera B Nacional teams: the former was not going to have any relegated team in its 2011–12 season and include sixteen teams from the latter, Primera B Nacional. The tournament would also include a team from the Primera B Metropolitana and one from the Torneo Argentino A, creating a thirty-eight team league. These changes were strongly opposed by the media and the people, and finally the tournament was called off.

The 20 teams play two single round-robin tournaments each year: the Torneo Inicial from August to December and the Torneo Final from February to June which determines the champion of the season unlike the Apertura and Clausura seasons that proclaimed a champion each.[15]

Since August 2014, a new tournament (named "Torneo de Transición") is being held, with 20 teams participating (17 from the 2013–14 season and 3 promoted from the 2013–14 Primera B Nacional). No teams will be relegated at the end of the championship.[16]

From 2014, the format will switch to a tournament with 30 teams. The first five clubs of the Zonas A y B of 2014 Primera B Nacional season will be promoted to the Primera División. Those 10 teams, with the addition of the 20 clubs currently participating in the top division, will contest the next season.[17]

In November 2014, the AFA announced the format for the next five seasons of the Primera División:[18]
From February to December 2015, the league will be contested between thirty teams. Two teams will be relegated to and two teams will be promoted from Primera B Nacional.
In the first half of 2016, the league will be contested between thirty teams. Three teams will be relegated to and one team will be promoted from Primera B Nacional.
From August 2016 to June 2017, the league will be contested between twenty-eight teams. Four teams will be relegated to and two teams will be promoted from Primera B Nacional.
From August 2017 to June 2018, the league will be contested between twenty-six teams. Four teams will be relegated to and two teams will be promoted from Primera B Nacional.
From August 2018 to June 2019, the league will be contested between twenty-four teams. Four teams will be relegated to and two teams will be promoted from Primera B Nacional.

Superfinal[edit]

Once Inicial and Final tournaments have finished, both winners have to play a match for the Copa Campeonato (familiarly known as Superfinal). The AFA had determined that the first edition (played in 2013) would be considered as a Primera División official title (2012-13 season), therefore Vélez Sársfield awarded its 10th official championship after defeating Newell's.[19]

Nevertheless, from the 2014 edition it was determined that the Superfinal would not be considered as a Primera División title but an official cup.[20]

Relegation[edit]

Relegation is based on an averaging system.[21] At the end of each season, the two teams with the worst three-year averages and the worst positioned team in the season table are relegated, and the best team in the Primera B Nacional is promoted while the promotion of the other two is yet to be decided. There will be three promoted teams per season. Newly promoted teams only average the seasons since their last promotion.

Averaging was instituted in 1983, two years after San Lorenzo de Almagro were relegated in 1981. That year, River Plate finished 18th out of 19 teams and would have been relegated under the old system. Racing and Nueva Chicago were the first teams to be relegated on average.[22] Boca Juniors was also struggling at that time and had a dismal 1984 season. These facts have led some to speculate that the averaging system was instituted to minimize the chance of big teams being relegated.