In the NLDS in 2004 with Houston, playing against Atlanta, he was 10-22 (.455), 4 HR, 9 RBI in the five game series. He was on another level against St Louis when he was 10-24 (.433), 4 HR, 5 RBI. He also drew 8 walks as the Cardinals decided wisely not to pitch to him after a while.
Add in his quiet 1-4 in this year's Wild Card play-in game against the Braves and Beltran for the postseason is hitting .378 (42-111), 14, 25 with 9 2B in 30 career postseason games. He has 24 walks and 15 strikeouts (just 13.5 percent of the time) and has a SLG of .838, OBP of .489 for a 1.327 OPS.
The only thing holding Beltran back from being a top postseason player is the fact that he has not played in a World Series. He single handedly nearly took the Astros past the Cardinals in 2004 as they lost in 7 games, giving him two game 7 losses in the NLCS. It remains to be seen if he can keep up this level of play in the World Series. His division series and championship series numbers are up there with the best of all time.