National League Division Series

In Major League Baseball, the National League Division Series (NLDS) determines which two teams from the National League will advance to the National League Championship Series. The Division Series consists of two best-of-five series, featuring the three division winners and the winner of the wild-card play-off.

The Division Series was implemented in 1981 – for only one year – as a result of a midseason strike with first-place teams before the strike taking on the first-place teams after. After 1993, Major League Baseball decided to implement the Division Series permanently, because it was restructuring each league into three divisions. (The implementation of this decision, however, was delayed a year, until 1995, due to the 1994–1995 players' strike.) 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 (who finished with a losing record from 1993 to 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 2008, the Milwaukee Brewers became the first team to play in division series in both leagues when they won the National League wild card, 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-shortened 1981 season.

...
Wikipedia