how long does it required for a club to distinguish a future star from a flop?

how long does it take for a club to know who to invest on who to let go of? and whats the qualities you look at?

Epoto wrote:how long does it take for a club to know who to invest on who to let go of? and whats the qualities you look at?

Well, if you look at Marco Reus, Borussia Dortmund considered him not good enough when he was about 16 and released him to a then 2nd league club youth academy (Rot-Weiß Ahlen) as he was considered to weak and small. Only when he was about 20, his real class showed.

So in this case, you could say Dortmund sort of "gave up on him" when he was 16. It very likely depends on the youth coaches and the players, too. Quite some players shine at 17 or 18 in the respective U17 etc NTs and then their development stagnates, so you have both ways. I would say there is not one definite way to decide that, and there is probably some luck involved, too (does the right coach see the kid at the right time?)