[AlexD744]

Even if each team only competed at one regional, they still play different numbers of matches. Especially since some go to eliminations and other don't, unless your just basing this on qualifications. But even so a team at Florida played 9 matches in qualifyers, while a team in New Orleans may have played 12 or 13 (not sure of that number). I think an OPR over the whole nation would give you the closest things to an accurate ranking system. It would not be perfect but it would be close.