Gday Pat, here is something for you, an accidental 5 year study.
My son Max started on my beginners program at 15, 5 years ago. It consisted of squats, bench, deads, cleans, overheads, rows and chins.
He was 51kg.
He has just turned 21, trains 7 days a week, weighs 90kg, squats, in competition, not gym lifts, 270kg, benches 170kg paused and deadlifts 260kg. He is 21 and has numerous World Records and Medals from World Championships. Until 2010 he trained whole body, started 2007.
The base he laid training correctly from the beginning will hold him in good stead for the rest of his career. He has never ignored lifts that will be beneficial, here are a few "odd" vids