- Before 1969, the team with the best record from the AL and the team with the best record from the NL during the regular season played in the World Series.
- Between 1969 and 1993, there was one playoff round before the World Series (AL/NLCS).
- Between 1995 and 2011, there were two playoff rounds before the World Series (AL/NLDS, AL/NLCS).
- Since 2012, there has been a play-in game for Wild Card teams, adding an additional game to the format for Wild Card teams.
Has any two teams in the World Series ever get there without losing a game during the postseason?