They played 5 rather than 7 in 1980.
Houston, in its first post season, played Philadelphia, the loser of the NLCS in 1976 to the Reds plus 1977 & 1978 to the Dodgers.
The Phillies beat Montreal on the last Saturday of the season. The Astros needed a 1-game playoff against the Dodgers to win the division.
In other words, both teams arrived at the NLCS with a spent pitching staff.
Game 5 was one of the best post season games ever. It went into extra innings.
On the top of the 10th inning, the Phillies scored on Gary Maddox’s double. This is the same Maddox who had dropped a line drive and given LA a victory in the 1978 NLCS. A little justice for Maddox, a great player.
It was a great game.