IPv6
If there's a three-way tie in the NL Central standings, there would be a tiebreaker game, with the loser becoming a Wild Card. Then there would be a tiebreaker game with the winner of the first tiebreaker against the team that hasn't played a tiebreaker yet. The winner of that game would be the Central champ, and the loser would play a wild-card game against the other loser.