The new format will expand the Wild Card with two additional teams, one each in the American and National Leagues. As of now, the winner will be decided by a one-game playoff prior to the three-tiered postseason, which will remain the same.
The expanded playoffs were linked to the sale of the Astros by Drayton McLane to Houston businessman Jim Crane and their move from the NL to the AL, effective for the 2013 season. The Commissioner's Office and the MLB Players Association collaborated on those developments during the just concluded collective bargaining negotiations.
The Astros' shift from the NL Central to the AL West will give each league 15 teams and all six divisions five clubs.
Rob Manfred, MLB's executive vice president of labor relations and human resources and its lead negotiator during nearly 11 months of collective bargaining talks, said Tuesday that it was likely the determination to immediately expand the playoffs would be made by the first quarterly owners meeting in January in Paradise Valley, Ariz.
"Our agreement is that the union will allow us to expand the playoffs in 2012," Manfred said. "There's a process whereby we need to share with them what we intend to do with the actual postseason format and get everybody on the same page. March 1 is just an end [date] of the process. I think the clubs will have a pretty good feel where this is going well before that."
MLB has been studying how to expand the playoff for at least two years, and it became a hot topic of discussion in Selig's 14-man special committee that has been studying on-field improvements of the sport. So was the expansion of rosters to 26 players for certain doubleheaders, which is in the new agreement and will be implemented this coming season.
The playoff and realignment matters had to be collectively bargained because they involve scheduling, and the union made it clear that any playoff expansion would be tied to moving a team from the six-team NL Central to the four-team AL West to create better competitive balance.
"The expanded playoffs were certainly connected to it and wouldn't have happened without it," Michael Weiner, the union's executive director and lead negotiator, said.
The current Wild Card format and three divisions in each league were adopted in 1994. From 1969 to 1993, there were two divisions in each league and a League Championship Series between the first-place teams as a prelude to the World Series. Prior to 1969, only the pennant winners in each league met in the World Series.
The new format means that 10 of the 30 teams make the postseason, a breakdown that Selig has said is not objectionable.