Oklahoma is playing in Oklahoma City. How is this possible? Because the game is hosted by the Oklahoma City Sports Association and the Big Twelve.
The NCAA Division I Men's Basketball Championship returns to Oklahoma City March 18 and 20, 2016. The Oklahoma City All-Sports Association and the Big 12 Conference will host the first- and second-round games at the SMG-managed Chesapeake Energy Arena.
Every time Nationwide Arena hosted NCAA games, OSU was ineligible as the host school. Clearly the host doesn't have to be a school. Imagine the ticket demand if OSU played first and second round games at Nationwide.
*Mod Edit: More descriptive title