Some state playoffs have begun, but startup dates are staggered across the nation -- a few champions will be crowned this month, while others won't be determined until late March.
And the process varies, too. In some states, two teams from a region (or district or section) will move on to the next level of competition, which means the loser of the regional championship game lives to play another day. In other states, it's one-and-done.
As with all tournaments and playoffs, there is no guarantee that the best team will win. It is certain that a good team will, but a couple bad breaks (injuries, say), a bad call here or there (just ask Rutgers), or that banked-in three at the buzzer, and the favorite is history. Of course, that's what makes it so much fun.