1) Pro teams travel more via air/bus. There's a lot more exposure in various locations. (Most TX HS teams are within 3 hours of each other for most games)
2) They're testing more, so they're going to have more cases of the asymptomatic variety probably popping up than we would catch in our programs.
3) Blind luck. My district has so far been spared much since July. I feel like we're living on borrowed time with every rehearsal we get in while I hear about others losing weeks...
4) I guarantee there are coaches that are telling their players not to be tested. If they don't test positive for it they don't have to quarantine the team... The Players Union for the pros watches out for them. No one is watching out for the teenagers here.