I count four marque football programs in the B1G with the addition of USC, and those are OSU, Mich, PSU, and USC. If we based marque on national titles in the past twenty years, only OSU would be marque. Thus, the B1G should push to be a 20-team conference and add UM, FSU, ND, and Clemson. Three of those four have won titles since 2000. I know to some Clemson probably makes more sense as an SEC school, but it has fit in the ACC, so it can fit in a bigger B1G.
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Following Boarcane's reasoning, which really seems like where we are headed, the B1G could offer the four aforementioned schools and Pitt, Va Tech, UNC or UVA, and Oregon out of the PAC 12 to get to 24.