The NBA closed the book on high school starts straight to the NBA well over a decade ago as Howard Beck wrote then at the New York Times (subscription required). ln the past we’ve seen the likes of LeBron James (which would first come to mind for fans of the Cleveland Cavaliers), Dwight Howard and Kevin Garnett go straight from high school to the NBA.
Right now you must be 19 and a year removed from high school, but it appears that maybe coming to a end.