In VA - Public and Private separate. In publics - 6 classes. Each class has 4 regions which determine how many teams make the regional. It is not uniform across the state. Top 2 advance to "States" in single elimination. Regional Final is a "seeding" game with winner as #1 seed from region and loser as #2 from Region.
The 4 regions enter state tournament of 8 teams with bracket changing from year to year matching the various regions so that Region A play B in Year 1, C in Year 2 and D in Year 3. In round of 8 #1 seeds play 2's and it is single elimination.