From BR Bullpen
Between 1884 and 1890 postseason games were played only as exhibition matches. The first official World Series between the AL and the NL took place in 1903 WS. There was no such postseason in 1904 WS, however the tradition took on more permenance as of the 1905 WS season.
Up to 1968 the only post season series was the World Series, featuring the teams who won their respective league titles. The leagues were not yet divided into Divisions. The winners of the titles had to have the best overall record in their league.
With the expansion of 1969, the leagues were divided into East and West Divisions, necessitating League Championship Series. From 1969 to 1984 these series were held as best of five playoffs, and from 1985 until 1993 they were best of seven playoffs.
There was only one exception to this scenario, and it came in 1981 Postseason, and was caused by the 1981 strike. The strike came in the middle of the season, so a decision was made to have the leading teams of each division from before the strike play the leaders of each division from after the strike (see 1981 AL East Division Series, 1981 AL West Division Series, 1981 NL East Division Series, 1981 NL West Division Series).
In 1994 the leagues were further divided into three divisions: East, Central, and West. In order for postseason play to produce a winner in an even number of match-ups, a Wild Card winner was chosen from each league. This would be the team from each league who had the best overall record yet did not win their division. The three division winners along with the Wild Card winner from each league would play a five game Division Series. Ironically, the first year of this new arrangement did not go as planned. The 1994 strike cut the season short and postseason play was cancelled for the first time in 90 years. The first such postseason scenario took place in 1995 Postseason.
In 2012 the postseason was expanded again with the creation of a second wild card team in each league. The now 2 wild card teams per league would play each other in a one game winner take all round hosted by the team with the better record. The winner would then advance on to the Division Series to play the team with that league's best regular season record, regardless of division.
- 1 game Wild Card round
- Best of 5 Division Series
- Best of 7 League Championship Series
- Best of 7 World Series