* Back Spin *

** a.k.a. *** Loophole *

* Patented by F. Lammertink 1992, copyright 1991 Binary Arts. *

(plastic, 6 inches diameter by 1.25 inches thick)

Two discs that can rotate with respect to each other hold a total of 35 balls in six three ball slots on each side,
at any time one slot is missing one ball,
creating a gap into which a ball from that slot can be rolled or a ball from the other side can be pushed through if the discs are rotated appropriately.
The slots on each side are arranged as three spokes and three outer slots;
the three colors of the balls in the spokes are the same as the three colors of the outer slots on the opposite side.
*Jaap's Page*
observes that this puzzle is relatively easy to solve by first solving the inner two balls of each spoke and then the remaining balls,
essentially correcting one ball at a time.

**Further Reading**

*Jaap's Page*,
from: http://www.jaapsch.net/puzzles/backspin.htm

*Lammertink Patent*,
from: www.uspto.gov - patent no. 5,172,912