Watching the gymnastic competition in the Olympics and was struck by the obvious.
On the beam, for example, it's all circular movement around a center that must stay over the beam. They may flip frontwards or backwards, or turn, or in one amazing move, flip and twist in the air landing facing the other direction, but it is all circles around a maintained center. To the extent that they can perform their moves and keep their one point, they stay on the beam.
This is not to say there is anything easy about gymnastics. Only that I am seeing the four basic principles used over and over by athletes at a very high level of training.