All "Primera Metropolitana" tourneys cover the area in and around Buenos Aires, the capital city. The "Torneo Reducidos" (reduced tournaments), however, involve 8 teams below the top two, as opposed to 4. Before the top-flight Argentine Primera División abandoned its traditional Apertura and Clausura format in 2015 in favor of an expanded single season, there was no playoff between the Apertura and Clausura winners. As a result, the league crowned two champions each year. After each Clausura, the two teams with the lowest points-per-game total for the previous six tournaments (three years, counting only Primera División games) were relegated to Primera B Nacional to be replaced by that league's champion and runner-up teams; the two teams immediately above contested promotion/relegation series with the third and fourth places in Primera B Nacional, counted by its aggregate table. In Primera B Nacional, the same procedure continues in use for relegation to either Primera B Metropolitana or Torneo Argentino A for non-Buenos Aires clubs. From 2015 onward, relegation from the Primera División will be based solely on league position at the end of the season (which, effective in 2016–17, changed from a February–December format to an August–June format). The Australian A-League, which also features a team in New Zealand, has determined its champions via a playoff system, officially known as the "Finals Series" (reflecting standard Australian English usage), since its inception in the 2005–06 season. From the league's inception through the 2008–09 season, the top four teams advanced to the finals series, employed using a modified Page playoff system. The top two teams at the end of league play were matched in one semifinal, with the winner advancing directly to the Grand Final and the loser going into the Preliminary Final. The next two teams played a semifinal for a place in the Preliminary Final, whose winner took the other place in the Grand Final. Both semifinals were two-legged, while the Preliminary Final and Grand Final were one-off matches. When the league expanded to 10 teams beginning in 2009–10, the finals expanded to six teams. The format of the six-team playoff established at that time was:  Starting with the 2012–13 season, the finals format has been changed to a pure knockout tournament consisting entirely of one-off matches:  The concept of a finals series/playoff is standard in Australian sport.