Others might disagree, but an 8th grader who has placed and won at national tournaments would probably do fine there. It could be an eye-opening experience about how tough the training and competition is at the higher HS level, but if he is tough, works hard already, and probably trains with some older guys anyways, I'd sign him up. But that's as 'low" as I'd go. In other words, I wouldn't send a 7th grader even with similar credentials.