NBC has already had its share of bad luck (and bad ratings) this fall. Now there may be more on the way. MLB’s decision to postpone tonight’s Game 6 of the World Series to tomorrow night because of bad weather means that if the series goes to a seventh game, it will likely air on Friday — against the series premiere of Grimm and the final-season premiere of Chuck on NBC. NBC already pushed the shows’ debut by a week to create a Halloween-themed block on Thursday and Friday this week, so another delay seems unlikely. As for Fox, it had already cleared both Wednesday and Thursday night for baseball, so it will air Glee repeats tonight. If a seventh game is needed, the network will preempt the originals of Kitchen Nightmares and Fringe, currently slated for Friday.