Carlson Gracie Rio de Janeiro’s head instructor Ari Galo explains his concept of the ‘Ball guard’. It’s basically similar to the inverted guard but think of yourself as a giant ball that cannot be passed or controled. If your opponent pushed on one side, your hips and legs go over the other an so so forth.
Ari Galo also shows the difference between a traditional open guard and his ball guard.
Here you can see his concept in more detail as he rolls without using any grips:
