NC went to an opened up format originally for the 1A schools because there was such disparity in size between the smallest and the largest schools and most of the 1A's are clumped to the far east and far west of the state with few in the middle.
The other class coaches saw the chance to say "Hey I took us to the playoffs too" and thus the 4 classes subdivided into 8 state champions was born. When first introduced, we had 1 win teams qualifying in certain split class conferences if that one win was a conference game. This has subsided some but it is still possible to reach the playoffs with a sub- .500 record if some of your wins are in-conference.
NC playoffs now last 5 weeks. The season begins the middle Friday in August and is over the last Friday in October, normally. The weeks have been tinkered with to allow an extra playoff week, be done before the NC-SC Shrine Bowl Game in December, and try to keep the basketball coaches from griping so much about playoffs running into their season.
This Friday is the East and West Region finals (state sem-final level) with 11/30 & 12/1 being the State Championship games spread between UNC, NC State, And Wake Forest's stadia.
When gas got so high 2-3 years ago the state introduced the Pod System to cut down on travel. This turned the first and even second round games into little more than a conference tournament with many schools playing the same opponent from Season Week 11 to Playoff Week 1. The coaches hate it, the fans hate it, and I'm not so sure the officials are much a fan of it either. Thus the state has deemed it good and says its here to stay for the forseeable future.
There are a lot of first round blowouts but reviewing the scores from last Friday's 3rd round games, at least 12 had winning scores of 50+ with 20-30 pt. margins so we've probably got some conferences much weaker than others.