Newton’s Law of Motion.

A body in motion tends to stay in motion unless acted on by outside forces.

When playing the Orbiter, these are some of the forces that the ring will encounter.

   1.    There is a constant restricting force caused by the fact that the ring is tied to a string that is tied to a post. The string restricts and slows the ring.

   2.    Gravity constantly pulls the ring down and causes it to slow.

   3.    Momentum affects the ring and helps it to move along its path.

To work with these forces and complete a successful swing, you have to exert onto the ring precisely the right amount of force and in the right direction. If you do these two things, the ring's forward motion will finally be stopped when it lands onto the top of the second post for an orbiter ringer.