ALCS is an acronym that stands for American League Championship Series. It is the penultimate series of the playoffs, with the winner going on to represent the American League in the World Series. It is a best-of-seven series, with the first two and last two games of the series played at the team’s ballpark which holds the home-field advantage in the series.
Home-field advantage is determined as follows: Division champions have home-field advantage over a wild card team, and if both participants are division champs or both are wild card teams, then the team with the better regular season record gets home-field advantage for the series.
History of the ALCS
Up until 1969, the American League team with the best regular season record went to the World Series without a playoff. In 1969 the American League split into two divisions (East and West), and the teams with the best record in each division would face off in the ALCS to see who would go to the World Series. This was a best-of-5 series until 1985 when it went to a best of seven, which it still is today.
The New York Yankees have played in the most American League Championships, with 18 appearances. They also hold the record for wins, with 11. The Boston Red Sox have won in 6 of their 12 appearances, the Oakland Athletics have won 6 of their 11 appearances, and the Baltimore Orioles have won 5 of their 10 appearances. The most common matchup has been the Kansas City Royals vs the New York Yankees, with four head-to-head matchups in the ALCS (1976, 1977, 1978, 1980). The Yankees have won three of those four series.