[EricH]

Originally Posted by Zanfardino2892

but how would you define possession? I know that-

"POSSESSION: Controlling the position and movement of a BALL. A BALL shall be considered in POSSESSION if, as the ROBOT moves or changes orientation (e.g. backs up or spins in place), the BALL remains in approximately the same position relative to the ROBOT."

but if the balls are free spinning can you still control the general direction of the balls?

If the robot were to suddenly stop, reverse, or spin, would it have to chase a ball that it was pushing before that sudden movement? If the answer is no, the ball is possessed. If the answer is yes, the ball was probably not possessed.

Take a look at 16's robot from 2008. It had a large frame that came down over the trackballs. If that frame had been bigger, big enough that the trackballs weren't squeezed, 16 would still have been in possession of a trackball when the frame was around it. If it had had one open side, possession would not necessarily have been the case.