I think the rule of thumb is 2 years or less and they can wrestle novice. Anything over 2 and they need to go to open. That's also the most straight forward and uncomplicated way to approach it. That being said, I have a few kids each year making the transition that don't have any business wrestling open yet and unfortunately, more often than not they will drop out. Many times, I will just encourage those wrestlers (and parents) to practice only and stick with the sport, with the hope that they will eventually mature physically and athletically in a way to match their peers.