Jugglers needed (base version): 4 intermediate
Two more diagrams would be needed to show a complete cycle, but it's fairly
easy to understand what's happening. A&D always move in the same direction
in a square, movin from corner to corner after each pass. B&C do the
same in their own square. Passes are made alternately to each of the two
passers in the opposite square. In a version that may be easier, passes
may always be made to the same person if A&D rotate in the opposite direction.
The rhythm is usually a 4-count.
For a 6 jugglers version, try prism.