With all the bowling ball choices now in the marketplace, it can be confusing as to which ball to buy. My first suggestion is to start with a reputable pro shop with experience in fitting the ball to your grip. A proper grip is one of the most important requirements for your new ball. A new high performance ball that does not fit will probably lower your score rather than raise it. This is because subconsciously, you will be squeezing to hold on to the ball rather then having a loose arm swing and rolling the ball over your target. The pro shop owner also knows the performance characteristics of each ball and can help you make the proper selection to suit your game, the lane condition you bowl on, and your pocket book.
As far as choosing a ball, each ball is designed to suit a different lane condition. Any balls can strike if the lane condition (or oil) matches the performance characteristics of that ball. Proper ball selection is the key to high scores. A bowler cannot out-execute a bad ball reaction. A good ball reaction will create area on the lane, making it easier to get to the strike pocket. This results in a loose arm swing, which is the key to throwing strings of strikes.
So how do you choose the proper ball? There are three primary properties that determine the design performance of a ball:
• Shell material
• Radius of gyration (Rg)
• Differential Rg
There are four major shell materials. Polyester (also called plastic) balls are colorful balls that have very low friction. Friction is the property that measures how well the ball grabs the lane to create hook. Therefore, the low friction of polyester balls hook the least and are mostly used to throw a straight ball, especially for spares. Urethane balls are very durable balls that will try to hook in the oil, but are not aggressive enough to snap hard on the backend of the lane. These are good balls for a lower average bowler's first ball. They are controllable with medium hook on the backend of the lane. Reactive resin shells are the high performance balls of the 90's. They slide on the oil applied to the front part of the lane and then snap on the dry backend of the lane. Reactive shells create greater entry angles into the pins and more total hook. On some conditions, these balls can hook too much and they become uncontrollable. The newest shell materials are the particle technology shells. These balls have microscopic particles mixed into the shell to bite through the oil and grab the lane. This creates the most hook in oil of any shell material.
The radius of gyration (commonly known as Rg) tells the weight distribution inside of the ball. This is determined by the core design. ABC specifications allow the maximum weight for a bowling ball to be 16 pounds. The weight can be located in the core close to the center of the ball, which would be a low Rg ball, or in other words, a center-heavy ball. Or, the weight can be located near the outside of the ball, which would be a high Rg ball, or cover-heavy ball. A center-heavy ball will be easier to rotate or roll down the lane. Therefore, a low Rg, center-heavy ball, is good for oily lane conditions because it will try to roll as soon as it touches the lane. A ball that rolls early will not snap on the backend. Therefore, the characteristics of a center-heavy ball are early roll with an arcing ball path. They are good for oily conditions and lanes that have oil carrydown on the backend of the lane.
A high Rg ball is a cover-heavy ball. In these balls, the majority of the weight is moved towards the outside of the ball closer to the shell. This weight shift to the outside makes it slide further down the lane and then hook sharper when it gets to the dry backend. The problem that occurs is that on carrydown oil, it may want to slide too far.
The last major property is differential Rg, which is also very important. The shape of the core will result in a preferred axis of rotation. As the ball rolls down the lane, the track, which can be seen as an oil ring around the ball, will move to rotate about the preferred spin axis. This creates many rings of oil on the ball and is called a flared ball track. The rings of oil will actually separate, creating a gap between them on the ball surface. As the ball rolls down the lane, the contact point of the ball with the lane is constantly changing. The oil that was picked up from the lane onto the ball track is not in contact with the lane again. Therefore, the flare ball track creates more friction with the lane due to no oil being on the area of the ball that is contacting the lane. This creates more hook. The differential Rg is the property that determines the spacing between oil rings. High performance balls all are designed to create this track flare for added hook.
Those are the three major properties in determining the reaction of the ball on a lane. By knowing the amount of oil on the lanes, a ball can be selected to match up to that condition. A pro shop owner is very good at helping you with this selection process.
For example, if you bowl on a heavy oil condition, you would want a strong hooking ball. The shell should be a particle technology. A low Rg core is needed to get the ball into a early roll, and a higher differential Rg will create track flare for more friction.
If you are bowling on a medium oil condition, a reactive resin cover will help get the ball down the lane and still hook on the backend. A medium Rg to low Rg core will ensure the ball gets into a roll. A medium differential Rg will add to the backend hook. What ball will actually work the best will be decided by the amount of carrydown.
When purchasing a ball, these concepts should be kept in mind. In developing a ball arsenal, you need balls that react differently to match different lane conditions. By mixing these properties in your ball arsenal, you can have a ball reaction that matches up with any condition. The goal is to always to find a ball reaction that will give you area to the get to the strike pocket so you can relax, roll the ball, and string strikes in a row.