The 1999 National League Championship Series (NLCS), to determine the champion of Major League Baseball's National League, was played between two East Division rivals, the division champion Atlanta Braves and the wild card New York Mets.
After the Mets lost eight of nine games in September—including five of six to the NL East rival Braves—the Mets seemed unlikely to make the playoffs, two games out of the wild card lead with three games to play.
Following the Mets' most recent defeat in this stretch, an eleven-inning loss to Atlanta at Shea Stadium, Braves third baseman Chipper Jones was quoted as saying, "Now all the Mets fans can go home and put on their Yankees stuff." Braves closer John Rocker was also quoted as saying he hated the Mets, and "How many times do we have to beat them before their fans will shut up?" Thinking they had buried the Mets, the Braves had closed out their season with another division title and were poised to enter the playoffs and leave the Mets behind.
However, the Mets swept their season-ending three-game series with the Pittsburgh Pirates at Shea Stadium, while the wild card leading Cincinnati Reds lost two out of three to the Milwaukee Brewers. The Mets and Reds had the same record at 95–66 heading into an eventful final day of the season. That Sunday saw the Mets win their game, 2–1, on a wild pitch in the bottom of the ninth; the Reds avoided the sweep in Milwaukee following a seven-hour rain delay. Both teams finished even with records of 96–66 after 162 games.
Per MLB rules, the one game wild card playoff was held the next day, October 4, at Cincinnati's Cinergy Field. Al Leiter shut down the Reds with a two-hit shutout in a 5–0 Mets victory, sending New York to its first playoff berth since 1988. (As the wild card team, the Mets would be scheduled to play the division winner with the best record. However, since that team came from their own division—the 103–59 Braves—New York faced the team with the second best record, the 100–62 Arizona Diamondbacks.)
In the National League Division Series, both the Mets and Braves would advance in four games. The Mets would defeat the Arizona Diamondbacks, with the series ending on a walk-off home run by seldom-used backup catcher Todd Pratt, only playing due to a thumb injury to star catcher Mike Piazza. The Braves would vanquish the Houston Astros in four games, with Brian Jordan and eventual National League MVP Chipper Jones leading the way. And that would set up a National League Championship Series that was anticipated by many, pitting two bitter rivals against each other on the national stage. This marked the Braves' record eighth-straight appearance in the NLCS, while the Mets advanced to the league championship for the first time since 1988. This would be the second time that the Braves and Mets met in the NLCS. The two teams met in the very first National League Championship Series in 1969, with the Mets sweeping the best-of-five set.