Pistons is an asynchronous four
ball pattern in which every ball is thrown along its own vertical path. It is
essentially a Fountain where the balls do not travel in circles, but are
instead thrown in columns. Though it may look difficult to perform, Pistons
is actually a fairly simple and easy trick.
Before learning Pistons, it is important that you already know how to do a vertical Two-in-One in each hand.
To learn the full pattern, start with two balls in each hand. Then, make a vertical throw with your dominant hand near the center of your body. When that ball is almost at its peak, make a similar throw from your non-dominant hand. When the first ball begins falling back down, throw the second ball in your dominant hand vertically along the side of the first ball. When the second ball (thrown from your non-dominant hand) begins falling back down, throw the last ball from your non-dominant hand vertically along the side of the second ball. Then catch all the balls.
Practice these first four throws, making sure to maintain consistent and accurate timing. To fully run Pistons, just keep making throws in the same pattern as the first four, and eventually you will get into a rhythm.