Here is an example of some moveable flagpoles.  They are a solid free standing pole with a propeller type design that allows either side to be up.  The ends of the propeller can be painted or have flags attached and can indicate when a team owns or has capture a flag point.

Materials
1x 4x4 pole
4x 2x6 pieces for base
1x 60inch 1x4
1x 6" bolt ( a 5" would probably be fine, I need to trim these now.)
3x nuts (one to keep the bolt in place and 2 to counter tighten and adjust prop tension)
3x washers to create smoother rotation.