As we are now starting to see some academies bear some fruit in terms of A-league players coming through and then eventually being sold, im genuinely curious as to how they operate.

Do they scout players from other local teams and then have the best players in one team then play against the local teams within that state competition? That seems a bit unfair
Do they play up age groups?
At what age do they essentially "age out" if they arent going to make it as a professional footballer. 

For example, i see that in the under 18 Victoria competition last season, the three A-league teams finished 1st, 2nd and 3rd in that competition. How is that good for anyone? Victory had a goal difference of around 60.