Who'd a thunk it?
Anyway, here are how some possible scenarios would play out from an MLB article.
What if the AL East and Central divisions end in ties?
Next Monday, the Red Sox would play the Yankees at Yankee Stadium and the White Sox would play the Indians at Jacobs Field. The losers would then play a Wild Card playoff game on Tuesday to determine the AL's final playoff setup. The Yankees would play the Indians at The Jake; the Red Sox would play Cleveland at Fenway Park; and all combinations against the White Sox are yet to be determined.
What if those divisions are won outright and two teams in the AL Wild Card race finish with the same records?
Next Monday, the Yankees would play the Indians at the Jake or the Red Sox would play Cleveland at Fenway Park. All combinations against the White Sox are yet to be determined.
What if the Yankees, Red Sox and Indians all finish with the same records?
The Yankees and Red Sox play in New York for the AL East title and the loser plays the Indians for the Wild Card berth on Tuesday. New York is at the Jake if the Yanks lose and the Tribe is at Fenway if the Red Sox lose.
Why, you might ask, is there a Wild Card playoff game when the Indians would have a half-game better record than the Yankees-Red Sox loser? MLB has determined that it would not be fair for a team that's tied for a division title at the end of the regular season to be displaced in the postseason by a second-place team. Thus, the mandatory Wild Card playoff game.
What if the Yankees tie the Red Sox in the AL East?
Next Monday, the Yankees would host the Red Sox, unless those two teams finish with the best records in the AL. In that case, there wouldn't be a playoff game. Both teams would make the playoffs and the first-place team is determined by the two teams' head-to-head record. As of Tuesday, the Yankees led the season series, 9-7.