2017 MLB Magic Numbers

Two-way tie for the division or wildcard

1. A one game tie-breaker is played between the two teams, winner take all.

Two-way tie between division winners

1. The team with the best record in head to head play.
2. The team with the best overall record in intra-division games.
3. The team with the best record in the final 81 games of the season, ignoring inter-league play.
4. The team with the best record in the final 82 games of the season, extending backward until the tie is broken.

Three-way tie for the division or wildcard

1. The team with the best intra-division record is determined as Team C. If intra-division records are tied, refer to above tie-breakers to determine team C.
2. The other two teams, A and B, play one game.
3. The winner of this game plays team C in one game.
4. The winner of this second game is the winner of the tie-breaker.

Tiebreaking prodecures from MLB.com