When I was a child living in Augusta, GA, the main HS was "Richmond Academy", public not private. Each year they would start out 9-0 it would seem beating to a pulp teams like Martinez and whatever else. Then they would play Valdosta and get absolutely demolished. I don't think they ever beat Valdosta.
I later learned that back in the day the businessmen in Valdosta would "scout" good junior high players, find out what their dad did for work, and offer him a lucrative job in Valdosta to get him to move, with his son of course, and perhaps younger son who had talent. This was back when segregation was still in force in practice is not legally. I don't think Georgia high schools yet had black players at all, which is "interesting".
So, Valdosta would run through the schedule and championships almost every year. This apparently was legal.
Today, they are still competitive even though neighboring programs are also quite good at times, and the ATL metro schools can be powerhouses as well, including the one I attended.
The South can be interesting.