The National League Division Series is comprised of two concurrent best-of-five game series featuring the three division winners and a wild card team.
The NLDS uses a 2-2-1 format. The team with the best record gets the three home games—the first two games and the last one (if necessary). The wild card team can never have home field advantage.
The winners of the NLDS advance to the next round of the MLB postseason which is the National League Championship Series. The winner of that round goes to the World Series.
Preceding the NLDS, is the NL wild card game. This contest pits the two wild card teams (the two teams with the best record who failed to win their division) in a one-game playoff.
The winner of the wild card game advances to the NLDS.
The wild card team that advances to the NLDS plays the division winner with the best record. It no longer matters if the NL team with the best record and the wild card team are from the same division, they will still play each other in the division series.
The first time Major League Baseball employed the NLDS format was in 1981 when a player’s strike cut the seasons into halves.
Major League Baseball decided that the winner of the first half of the season would face the leader of the second half the season in the NLDS.
This decision resulted in the Montreal Expos tackling the Philadelphia Phillies and the Los Angeles Dodgers clashing with the Houston Astros.
The downside to the aforementioned idea was it excluded the two teams—St. Louis Cardinals and Cincinnati Reds—who had the best overall records.
The NLDS was implemented for good in 1994, the same year the league was realigned into three divisions. No NLDS was held in 1994, however, as another player’s strike cancelled the MLB playoffs.
That made 1995 the first year baseball fans actually got to experience the new MLB postseason format.
In the 1995 MLB playoffs, the Atlanta Braves dispatched the Colorado Rockies in four games and the Cincinnati Reds swept the Los Angeles Dodgers.
The Atlanta Braves are perennial NLDS participants. Their most frequent foe has been the Houston Astros.
The two teams tussled in the NLDS in 1997, 1999, 2001, 2004, and 2005.
It’s highly unlikely that those two teams will ever meet in the NLDS again as the Astros are now members of the American League.