I think they are saying that
If OU (7-2), then they beat OSU and ut in all three-way ties, probably playing ISU.
IF there is a four way tie, then tu > ISU. So OU is 2-1, tu is 2-1, ISU is 1-2, & OSU is 1-2 in the four-way round robin. Hope this helps.
RE: The article writes, 'Texas (4-2) is...