The National League Division Series (NLDS) is a best-of-five series. This means each matchup in the NLDS can have a maximum of 5 games. The first team to win 3 games in a series advances to the next round, the National League Championship Series (NLCS).
So in total, there are 2 NLDS series, each can have up to 5 games, but the exact number played in any given year depends on the outcomes of those series.
