I think it's by classification from what I've seen by graduate year so it sounds like you're following the model that the Thunder have here.... THE difference is neither the Thunder NCDC VS. Premier is sanctioned by USA Hockey.... NCDC is on par w/ the Nordiques of the NAHL as both are Tier II, JUST AS THE original Nordiques that was shuttered by the current ownership of the NAHL entry is on par w/ the Thunder Premier team from what a quick check of searching what is the difference.....Is there a pretty big skill gap between ncdc and premier? I live in Idaho Falls and our premier team is part of the ncdc expansion next season. Looking forward to it!