Not sure where you're getting your info, but it's wrong. Correct info is:
PSU opp: 1-3 (NW 1-1, Ill 0-1, Iowa 0-1)
OSU opp: 2-2: (Wisc 1-0, Minn 1-1, Purdue 0-1)
Mich opp: 1-3 (Neb 0-1, Minn 1-1, Purdue 0-1)
So as of now OSU would win the 3-way tie breaker