Lots of 9th graders start on varsity teams. And good ones too. Skilled, gifted players, that have played the game for 10 years, can play with anyone, as long as they have sufficient size to do so. Since many/most kids hit their growth spurt in 8th grade, there is no longer a huge difference in size between many 9th graders and 12th graders. In fact, for many of these players who were undersized until hitting puberty, it’s actually far easier playing against 12th graders than playing against post-pubescent holdbacks, a year or two ago. So, for many of these kids, it’s easier for them then it’s ever been since playing the sport.