The Division Series was implemented in 1981 as a result of a midseason strike with first place teams before the strike taking on the first place teams after. After 1993, it was implemented for good when Major League Baseball restructured each league into three divisions, but their next playing was in 1995 due to the cancellation of the 1994 playoffs. Previously, because of a players' strike in 1981, a split-season format forced a divisional playoff series, in which the Montreal Expos won the Eastern Division series over the Philadelphia Phillies three games to two while the Los Angeles Dodgers beat the Houston Astros three games to two in the Western Division. The team with the best overall record in the major leagues, the Cincinnati Reds, failed to win their division in either half of that season and were controversially excluded, as were the St. Louis Cardinals, who finished with the NL's second-best record. The Atlanta Braves have currently played in the most NL division series with thirteen appearances. The St. Louis Cardinals have currently won the most NL division series, winning ten of the twelve series in which they have played. The Pittsburgh Pirates (whose finished with a losing record from 1993-2012) were the last team to make their first appearance in the NL division series, making their debut in 2013 after winning the 2013 National League Wild Card Game. In 2011, the Milwaukee Brewers became the first team to play in division series in both leagues when they won the National League Central Division title, their first postseason berth since winning the American League East Division title in 1982 before switching leagues in 1998. Milwaukee had competed in an American League Division Series in the strike-shortened1981 season.
The wild-card team is assigned to play the division winner with the best winning percentage in one series, and the other two division winners meet in the other series. (From 1998 to 2011, if the wild-card team and the division winner with the best record were from the same division, the wild-card team played the division winner with the second-best record, and the remaining two division leaders played each other.) The two series winners move on to the best-of-seven NLCS. The winner of the wild card has won the first round 7 out of the 11 years since the re-alignment and creation of the NLDS.[needs update] According to Nate Silver, the advent of this playoff series, and especially of the wild card, has caused teams to focus more on "getting to the playoffs" rather than "winning the pennant" as the primary goal of the regular season.[1]
Initially, the best-of-5 series played in a 2-3 format, with the first two games set at home for the lower seed team and the last three for the higher seed.[2][3] Since 1998, the series has followed a 2-2-1 format,[4] where the higher seed team plays at home in Games 1 and 2, the lower seed plays at home in Game 3 and Game 4 (if necessary), and if a Game 5 is needed, the teams return to the higher seed's field. When MLB added a second wild card team in 2012, the Division Series re-adopted the 2-3 format due to scheduling conflicts. It reverted to the 2-2-1 format from 2013 onwards.[5]
One-time split-season format, due to strike (first half leader vs. second half leader); despite best overall NL East record, St. Louis Cardinals miss the playoffs
One-time split-season format, due to strike (first half leader vs. second half leader); despite best overall NL West record (and best overall NL record), Cincinnati Reds miss the playoffs
Todd Pratt hit a home run in the 10th inning of Game 4 to win series for Mets; Diamondbacks set new record by reaching postseason in only their second season
In one of the best pitching match ups ever, Chris Carpenter outduels his good friend Roy Halladay in the deciding Game 5 as the Cards eliminate the Phillies
Giants became the eighth team to win a five-game playoff after trailing 2-0; MLB's new playoff format makes them the first to do so by winning last three on the road
The Cubs set a postseason record with 6 home runs in Game 3, defeating the Cardinals, the team with the best record in 2015, in Game 4 to advance to their first NLCS since 2003
1996, 1997, & 2007 are the years in which the National League Division Series finished in sweeps in both series.
^Nate Silver, "Selig's Dream: The Wild Card as Enabler of Pennant Races," in Steven Goldman, Ed., It Ain't Over 'til It's Over (New York: Basic Books): 170-178.
^Gillette, Gary; Palmer, Pete, eds. (2006). "October Classics: Postseason Series and Playoffs". The 2006 ESPN Baseball Encyclopedia. New York: Sterling Publishing. p. 1656.