I learned about this exact drill from Bert Kinisters instuctional DVD called"Building the 6 pointed star".This is one of a few pre-drills that he reccommends that you get good at before laying out all the 6 balls that make up the 6 pointed star.
In the six pointed star layout:
The other four balls are placed on the long rail at the second diamond(on the rail) up from each of the four corner pockets in all kinds of different random numerical sequences using the 1,2,3,4,5 and 6 balls.The idea is to run out the balls in numerical sequence.Vary the ball placements for different runout scenarios.To simulate a nine ball experience, use the 4,5,6,7,8 and 9, so you get the feel of making that money(9)ball.
The six pointed star is a fantastic 9 ball drill.The drill Blackjack illustrated is also great for nine ball.Work on Blackjacks drill and then progress to the more difficult 6 pointed star.It's practice time well spent that you won't regret.
RJ