16 (as the Big XVI), then the zipper model may be the perfect model to use for its conference schedule. It would allow both divisions equal access to the state of Texas, it could implement protected cross-division games that make sense, and still allow the Red River Shootout to be an annual division game.

Even though it makes more sense for OU and Texas to be in opposite divisions, it would mean that OU and Texas would have to become protected cross-division rivals to ensure the Red River Shootout is played every year as a conference game. Also, it would mean Okie State would have to be in the same division as OU to ensure Bedlam is played annually. It would mean that Okie State would get paired up with a non-OK school (most likely Texas Tech or TCU) which doesn't make a lot of sense from a rivalry perspective.

The North-South model works only if the 2 OK schools are placed in the same division as the 4 TX schools. However, it means that the North is perceived to be weaker which could lead to less interest in the Big XII CCG.