Astros' Yordan Alvarez celebrates after after hitting a walk-off three-run home run against the Mariners in the ninth inning.

4 things we learned from Division Series Game 1s: Astros never die

It’s mathematically impossible to win a best-of-five series in Game 1. It’s figuratively possible to lose it, though. And a quartet of Division Series openers on Tuesday brought a bevy of surprises, heart palpitations and crucial pivot points, for Game 1 certainly and quite possibly for the series at large. Mercifully, the American League will…