Bruce Banner has no power over the Hulk. Bruce doesn't even remember what happens when he is the Hulk. He is afraid to turn into the Hulk all the time. Especially inside a Helicarrier. In one of the scenes, he crushed everything on his way and almost kill Black Widow, and fought with Thor.
But in the battle against the Chitauri in New York Bruce arrived on a small motorbike, did a maneuver and turned into the Hulk, who could understand where is the allies are and where is the villains.
I don't think that Bruce had learned to control him, because in Thor Ragnarok he didn't know that he spent 2 years on Sakaar.
So, why and how he could understand the situation?
