What is the most important task of a Project Manager? (makes a great dinner discussion if you want to get rid of your guests :))

Planning? No!
Control? You wished… NO!
Communication… HECK NO!

The answer is… allocation of scarce resources.

Come again?

You have limited time, your money pit is not without bottom, you have only a handful of team members, you have all those elements that you can only deploy in a certain way, and it's your job to allocate them in such a way that is most ideal in certain circumstances. 'Allocation of scarce resources" is the name of the PM game.

To be able to do this you need those risk analysis logs.
You need list of requirements that are prioritized.
You need a plan to see how decisions might affect current ideas about the future.
You need a clear goal to have a beacon to steer your project towards to.
You need communication to get the right information to base your allocations on.

You all need that. And more.

Still, on top of all this… allocation of scarce resources.

It is like a game of chess, it is all about moving your pieces.

And before anyone asks… most important PM skill is the ability to negotiate.