Those Extra Playoff Days
For the last who-knows-how-long, the World Series has started on Saturday night, with off days on Monday and Friday (if necessary), and Games 6 and 7 on Saturday and Sunday. Since Saturday is traditionally a day when no one watches television, Fox is understandably interested in moving the games to a more watched night. As a result, starting next year the Series will start on Tuesday night, with off days presumably on Thursday and Monday. Of course, this still means that Game 4 will be played on Saturday, but it prevents 2 games being played on that night.
Since the regular season will still end on a Sunday, with the playoffs beginning on Tuesday, there will be a couple of extra days in the playoff schedule. Sounds like they're going to use those extra days for additional off days in the Divisional Series. Since, ya know, playing 2 games in a row necessitates a rest.