There are three possible outcomes: The Mets could sweep, the Braves could sweep, or the two clubs could split the doubleheader.
If a team wins both games Monday, said club is in the playoff field alongside Arizona, with the loser of the doubleheader headed home for the winter. A split between New York and Atlanta would propel both teams into the playoffs and send the Diamondbacks packing, even though all three teams would have identical records. That’s because both the Mets and the Braves hold a tiebreaker over the Diamondbacks.
If the Mets and Braves split the doubleheader, Atlanta would be the No. 5 seed and New York the No. 6 seed, based on Atlanta’s winning the season series between the two. The Braves would then head to San Diego to face the Padres, while the Mets would return to Milwaukee to play the Brewers.
If a team goes 2-0 on Monday, that club, be it New York or Atlanta, would head to San Diego as the No. 5 seed, while Arizona would play Milwaukee as the No. 6 seed in a rematch of last year’s wild-card round.