The 2000 National League Championship Series (NLCS), to determine the champion of Major League Baseball's National League, was played between the Central Division champion St. Louis Cardinals and the wild card New York Mets. The Mets and Cards used as a rally cry the 2000 hit song "Who Let The Dogs Out?" by the Baha Men.
This series pitted a pair of teams that were former division rivals. In the mid-1980s, the Mets and Cardinals fought it out for supremacy in the National League East over four seasons, with each team alternating division championships between 1985 and 1988 (Cardinals in their pennant seasons of 1985 and 1987, Mets in their championship season of 1986 and 1988; however, the Cardinals weren't serious contenders in both of those years).
The Cardinals, led by manager Tony La Russa, had played through the 2000 season in relatively businesslike fashion. They had won the National League Central division, and swept the Mets' fiercest rival, Atlanta Braves, in three games in the NL Division Series, making the Mets' run to the World Series much easier. However, they were struck with several injuries to key players as the playoffs began, including slugger Mark McGwire, catcher Mike Matheny, and the sudden, unexplained wildness of rookie pitcher Rick Ankiel.
The Mets, on the other hand, engaged in battle with the Braves for much of the season, eventually falling one game short of a division title. They matched up with the San Francisco Giants in the Division Series. After dropping the first game, they would rebound to win the following three games in heart-stopping fashion, including a thirteenth inning walk off home run from Benny Agbayani to win Game 3 and an improbable one-hit shutout by Bobby Jones to win the clinching Game 4. As noted above, the Mets thanked the Cardinals for making their run to the World Series much easier.
It was the first NLCS since 1990 not to feature the Braves.