This passing pattern is based on the star (the passes and positions are the same) from which a juggler has been removed. Then you have an empty space and C should not throw to that 'hole'.  Thus C will start with no clubs (see variations at the bottom); all the others get 3 clubs.
Meanwhile, B does not receive any passes from the others, so when 3 passes have been made, he won't have any clubs left. At that moment, C will have 3 clubs, and will be about to throw a club in the hole. B now has to go through the pattern and be ready to catch C's pass.
Once B's there, you start again from the beginning, but B now has C's role and D has B's. That's the principle.  Now there are a few different ways to cross the pattern (running and hoping you won't get hit by a club is one of them). Here is another one that works on a 2-count.

In fact, B only does 2 passes in diagram 1. Before making his third pass, B steps in the middle of the pattern so that A's pass will travel just behind his neck (diagram 2). He now has to turn to be ready to catch C's first pass (diagram 3) while D's pass to A flies behind his back. By moving backward, he reaches his new position and can breathe again (diagram 4). D can now start to worry about himself.

See also the other runarounds.

Rhythms and number of clubs:
The above version uses a 2-count and 9 clubs.
But you can also play with the rhythm (between 2 and 4-count) and on the number of clubs (you can add 1 or 2 clubs--though I don't know exactly how--with the 4-count). The more clubs, the faster it gets.

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