Again whenever this gets brought up ...
The regional site selection the committee made pretty well guarantee that the Louisville region followed by the South Bend region will be the strongest two regions IF the committee continues to use proximity as their primary assignment criteria for each seed line. It is simple geography - 19 of the top 25 teams in this weeks AP poll are geographically closer to either Louisville or ND than to either Nebraska or Stanford. And of those 19 I believe 16 are closer to Louisville than South Bend. I imagine when the addition 39 teams in the field are selected that same kind of ratio will exist again - 80/20. What this means in conjunction with the proximity rule (if in force) is that the #1, 5, 9, 13, 17, etc teams in the committees estimation will in 80% of the cases be assigned to Lousiville and/or South Bend and that the #2, 6, 10, 14, 18, etc teams by the committees estimation will be assigned in 80% of the cases to the other of those two locations. If there is another rule involved that precludes that assignment, then the next closest location will be the other of those two regionals followed by Nebraska. Stanford (the West Coast regional) will by proximity rule as is always the case be the weakest regional because the 4th best of each seed line will get sent the furthest.
As soon as the S curve assignment of regionals was scrapped the idea of balanced competition went out the window - though everyone had plenty of complaints back then too.