A project manager plays with two major forces: Chaos and Freedom. When a project starts, nothing is clear, the previous stages like business analysis and user requirements collection have likely been a complete failure and collected input won't help much the team and the manager. At this point, the manager has to control the Chaos and reduce it to the minimum, by creating an environment where everyone know exactly what to do, how to do it and how much time would it take.
So he starts to plan, as the work moves on. The days roll out, and he slowly realizes that there is not much left of the initial planning, and the team is swirling out in different directions. This is where the Freedom control takes precedence. The manager has to give everyone enough Freedom so that every morning employees felt the urge to scratch an itch, while still working in the planned direction.
He slowly realizes that the Chaos/Freedom ratio is unique for each employee, and he has to work out a personal approach to everyone if the wants the team to work at full throttle.
By the time everything is crystal clear in his mind, and all the errors have been consumed and learned from, the project ends, and the manager moves on the next one or bails out.