Star Wars fans!! Why do they believe that Aniken is the chosen one to bring balance to the force?

Since Aniken ultimatly ends up becoming evil why is he seen as the chosen one? Was Qui-Gon Gin wrong in thinking he was the chosen one? Or does he restore the balance by fathering Luke Skywalker who ultimatly restores balance. Sorry if that is a messed up question but I am just trying to figure this out in my mind.