In a non-typical move, Obi Wan secretly uses a force push on Anakin from one of the observation decks high up on one of the spirals of the Jedi Temple. Then Anakin falls to his death and we lose all the movies!
No, in reality, IF Qui Gon HAD LIVED (which could not have happen since it was the will of the force i.e. George Lucas, for Anakin to fall) Qui Gon would have tried to give Anakin the room to grow, but no matter who trained Anakin, he still would have failed with the Tuskens, Padme, and the choices he made because Anakin believed his own hype about being the chose one.
I think a better question is what would have happen to Obi Wan? I don't think he would have become the great jedi he became because he would not have had Anakin to push him.