Their top teams don't play each other. tOSU is the only team that has played two of the other top four teams. The rest of the top-4 teams have only played one other top-4 team. The conference is so big and filled with so many mediocre teams that they can put together a fairly easy schedule for their top teams. No more playing all three of tOSU, Penn State and Michigan in the same season. Purdue, on the other hand, played all four top-4 teams.