Per the MLB site: A tiebreaker game will be played to determine a division winner, even if the tied clubs are assured of participating in the postseason. If a division championship tiebreaker is necessary, the head-to-head record between the clubs will determine home-field advantage. If the head-to-head record is tied, then division record will be the next tiebreaker.
Well, we know that the Yankees and Orioles split their 18 games this season. So, the division record will determine who gets home field in the tie-breaker game.
At this writing, the Yankees are 36-29 against the A.L. East and the Orioles are 38-27. So, it’s close – considering that both New York and Baltimore have games left other A.L. East teams.
Therefore, if the Yankees and Orioles are tied for first place at the end of the season, we know they would have to play a game on October 4th – with the loser than having to play the Wildcard playoff on the next day. But, where that game on October 4th will be played is still TBD.