To MLB's credit, they have eliminated the silly mid-series, non-travel off days in recent years. Again, this has never been done in baseball, dating back to the start of divisional play in 1969. It's not really a matter of sharing stadiums, or even TV (although TV has plenty of control), it's the logistics of trying to plan and carry out major events. You need more than 1 day advance notice to staff a stadium, for example. Imagine the Twins finishing off an ALCS sweep on Oct. 20 this year, knowing they are going to host World Series Game 1... but not yet knowing whether it will be Oct. 23, 24, 25, 26, or 27 (or possibly later, depending on NLCS weather), and only getting 1 day notice when the date is final. It's just not practical. As it is, the Twins already know exactly which days they will host potential games for the entire postseason (aside from weather delays, which they deal with in the regular season too). They can make all of the arrangements now, contingent only on their postseason qualification and advancement (and "if necessary" games are much easier to deal with than "we don't know if OR when the heck this is happening" games). (And yes, I have worked in stadium concessions, so I am the world's foremost expert on this subject )