This makes no sense if you are in different divisions. Different opponents.
MLB:
1. The team with the best record in head to head play.
2. The team with the best overall record in intradivision games.
3. The team with the best overall record in intraleague games.
4. The team with the best record in the final 81 games of the season, '''ignoring''' interleague play.
5. The team with the best record in the final 82 games of the season (provided the game added is not between the tied teams), extending backward until the tie is broken (Interleague games are skipped and ignored in this process.)