I have currently been buying a ball a year. Increasing the weight of the ball each time. Now that I have reached a weight where I will get the actual core in the balls I buy, I will start buying balls with different types of cores and for different conditions to experiment to help learn about different ball specs and also for different tournaments I end up participating in each year. I will probably slow down on buying balls once I get at least 3-4 balls that I am happy with.