I was just researching this same thing as I'm planning something for the night of the 30th -- I didn't find anything too concrete. I found that ESPN's MLB calendar of important dates shows playoffs starting Sep 30 / Oct 1. On the official MLB site, their calendar of important dates just shows a vague "October - Playoffs". Every team is done on the 28th unless there are important makeups or 1-game playoffs ... by looking at years past, even when there's been special 1-gamers, it looks pretty normal for the playoff schedule to kick off just two days later ... aka, the 30th. My guess is that two or three series will start on the 30th and one or two will start on the 1st. I'm scheduling my thing for the 30th anyways, hoping that if the Brewers make the playoffs and if they have home field, that the series will start on the 1st. Or at the very least, that the 30th won't be my one and only chance to see them in person in October this year.