Per the MAC's website:
TIE-BREAKER PROCEDURE
Ties in winning percentage, and thus for tournament, seeding positions shall be broken as follows:
1. Between TWO teams:
A. Head-to-head competition
B. Division Record (10 games)^
C. Winning percentage* vs. ranked conference teams (top to bottom, regardless of division, vs. common opponents regardless of the number of times played)
D. Coin flip
2. For MULTIPLE (3 or more) team ties:
E. Total won-lost record/winning percentage* of games played among the tied teams
F. Two (2)-team tie-breaker procedure goes into effect (refer to A)
[NOTE: Once a three-team tie has been reduced to two teams, the two-team tiebreaker will go into effect.]
^ - For the purpose of determining the Division champion. This tiebreaker is ONLY used for seeding purposes if the two teams in question are tied for the Division lead. (Teams will still be considered co-divisional champions)
* - Winning percentage is used instead of record because of situations where teams do not play each other the same number of times. Therefore, a team that is 1-0 (1.000) would win the tiebreaker over a team that is 1-1 (.500).