As mentioned in this thread:
Game 163s and on are sometimes required to sort out who makes the MLB playoffs. These games WILL NOT count in H2H leagues or leagues that are in playoffs. H2H games have a set schedule and will not be extended into Monday, etc in the case of Game 163s.
These games will affect season-long points and roto leagues, and will extend the deadline to start auctions and make waiver claims. They are regular-season games and will extend the Ottoneu Fantasy Baseball season.