Our HS has both kinds of tryouts, skills and scrimmages over a four day period. Several camps and open fields before the tryout also provide opportunities for kids to get a look.
Our HS will normally keep 20-25 Freshmen on the freshmen team, 18-22 on JV and 20-22 on varsity.
In discussions with the coach, he tries to keep every freshman who shows any kind of skill and basically won't be in a safety hazzard situation if they play. The most difficult cuts are at JV where things really get cut down and then again when 3-5 broken hearted seniors who don't make varsity and are let go. Every player is required to try out every year.
I think our HS coach does everything he can to provide the player to show he belongs and prove it.