WHETHER YOU are a 175-average amateur planning to make your initial purchase of one of approximately 150 reactive resin bowling balls that are currently available, or a professional seeking to supplement your current arsenal, you are embarking on a complex journey, fraught with peril.

However, just as it's considerably easier - and less dangerous - to negotiate a mine field if you know where the explosives are placed, it helps if you (or your pro-shop operator, a.k.a. "ball driller") understand all the variables associated with the ball selecting and drilling process.

Assuming that your ball driller has mapped out the proper span, pitches, finger inserts, etc., to meet your needs, you must now negotiate your way through the following array of options, not necessarily in order of importance:

1. Cover Stock Rating
2. Hook Rating
3. Surface Preparation
4. Radius of Gyration (RG) Rating
5. RG Differential Rating
6. Pin-In Configurations
7. Pin-Out vs. C.G. Position
8. Top Weight (pre-drilled)
9. Core Torque Rating
10. Ball Manufacturer

These are not the only considerations that you and your "equipment technician" must resolve, besides explaining what RG differential means. You should also deliver 10 to 15 shots on the lane of your choice so an assessment can be made of your physical game. A discussion should then commence in regards to the bowling center and/or lane conditioning procedure you are attempting to decipher, in relationship to your ability to score.

If, at this juncture, you are willing to place the decision regarding the ball and its "layout" solely in the hands of the ball-drilling professional, you need read no further. However, if you desire to make a more informed decision, you will need to understand the definitions and importance of the 10 key variables mentioned above. Only when you have an adequate understanding of these issues can you make an intelligent decision regarding your impending purchase.

1. Cover Stock Rating - This is usually broken down into three categories: 1) Highly aggressive, 2) Aggressive, 3) Moderate. It refers to coefficient of friction potential (porosity) based upon the products used in the construction of the shell (exterior surface). Highly aggressive ball surfaces are designed for oily conditions; conversely, a moderate coverstock is primarily designed for a much drier environment.

2. Hook Rating - This is a number that can range between 1 and 8, or 1 and 20, depending upon the ball chart, brochure, or advertisement you are reading, and refers to hook potential. (1 being the lowest, 8 or 20 the highest).

3. Surface Preparation - This has become a science unto itself. A ball can be rendered to three or four basic states: 1. Sanded (100 to 400 grit), 2. Polished (many compounds available), 3. Finessed and Polished (the process of taking a ball from 100 to 2000 grit, in four to eight stages, then applying various polishes, with each changing the friction potential, producing variations in skid-hook ratio).

4. Radius of Gyration (RG) Rating - Comprised of three categories, it refers to the Potential for Skid, based upon the interior design components. (The ABC/WIBC requires that every ball has its mass rotating not less than 2.43 inches nor more than 2.80 inches from the axis). The ratings used are a) High, b) Medium and c) Low.

5. RG Differential Rating - This is a measurable assessment of the ball's "track flare," which is defined as the migration of the ball track from the player's initial axis to the final axis at impact. The ratings used are: high, medium, and low. A large amount of track flare results in the ball's rotating on a dry surface with each successive revolution, thereby enhancing the friction potential. The maximum differential allowed by the ABC/WIBC is .080; there is no minimum figure.

   NOTE: Based upon the information divulged in the two previous ratings (RG and RG Differential), you can see that a High RG coupled with a Low RG differential provides increased skid; conversely, Low RG combined with High RG differential yields earlier hook, resulting in a diminished skid pattern.

6. Pin-In Configurations - This refers to drilling patterns that utilize a configuration wherein the pin or CM (geometric center of mass) and the CG (center of gravity) are one and the same; consequently, earlier hook, delayed hook (skid), stronger or weaker back-end reactions, and increased or decreased track flare can be achieved through the utilization of any one of five basic drilling lay-outs: 1. Label - Pin is placed 6-3/4 inches from your positive axis point (P.A.P.); 2. Half (1/2) Leverage - Pin is 5-1/16 inches from P.A.P.; 3. Leverage - Pin is 3-3/8 inches from P.A.P.; 4. Axis - Pin is 1-11/16 inches from P.A.P.; 5. Axis - Pin is on the axis.

1. Label Weight: This pin position, 6-3/4 inches from your positive axis point (P.A.P.), produces maximum skid, with average backends, and minimal track flare.

2. Half (1/2) Leverage: This pin position, 5-1/16 inches from your P.A.P., produces above-average length, with above-average backends, and above-average track flare.

3. Leverage: This pin position, 3-3/8 inches from your P.A.P., produces average length, with maximum backends, and maximum track flare.

4. Half (1/2) Axis: This pin position, 1-11/16 inches from your P.A.P., produces below-average length with below-average backends, and below-average track flare.

5. Axis Weight: This configuration places the pin right on the positive axis point (P..A.P.), which produces minimal length, minimal backends, and essentially no track flare.

   NOTE: If the individual whom you have contacted to prepare your equipment is not familiar with the terms "Positive Axis Point (P.A.P.)" and "Axis Coordinates (A.C.)," I suggest you seek assistance elsewhere.

6. Pin-out versus the CG Placement - This is a question that is answered by the combination of ball reactions needed to conquer a particular lane condition. In one situation, you might need above average skid with strong backends. This can be achieved with a pin-out of 1-1/2 to 2 inches. You then place the CG in the leverage position 3-3/8 inches from your positive axis point (P.A.P.), with the pin directly above, also 3-3/8 inches from your axis. This is commonly known as flip, double or stacked leverage. Conversely, the environment in question might require early hook with an above-average backend reaction. A solution to this dilemma would include a pin-out of approximately 3-3/8 inches. You would then place the pin in a leverage position, 3-3/8 inches from your positive axis point, which would allow the CG to be placed on your axis. This lay-out is referred to as an axis-leverage drilling.

   NOTE: Regardless of your pin placement, you can create an enhancement, diminishment, or additional reaction, through properly-designed C.G. positioning.

7. Top Weight (Pre-Drilling) - I advocate specific top weight for each of the seven basic drilling techniques. 1. Label: 2-l/2 to 3 ounces; 2. Half Leverage: 3 to 3-l/2 ounces; 3. Leverage: 3-l/2 to 4 ounces; 4. Half Axis: 2 to 2-1/2 ounces; 5. Axis: 1 to 1-1/2 ounces; 6. Double or Stacked Leverage: 3-l/2 to 4 ounces; 7. Axis Leverage: 2 to 2-l/2 ounces.

   NOTE: Your particular speed-turn coefficient can create a need for increasing or decreasing the amount of top weight required in reference to these recommendations. Analysis and experimentation, under the watchful eye of your teacher, can simplify this process.

8. Core Torque Rating - This particular characteristic is a new addition to most ball charts. It refers to the mass distribution within the core, and the internal lever arms making up the core structure. It is an indication of a ball's ability to deter "roll-out" (the ball's axis becomes too vertical prior to impact, producing inordinate deflection, yielding no "carry"). The ratings utilized are high, medium, and low, with "high" referring to an aggressive transition from skid to hook. Conversely, a low core torque rating yields a very subtle change-over.

9. Ball Manufacturers - A few of the established manufacturers who come to mind are AMF, Brunswick, Columbia, Ebonite and Faball. Some of the more recently formed companies are Ballistic, Dyna-Thane, Sports Tec, Storm, Track and Visionary. Each of the aforementioned produces some very fine bowing balls; however, one of the most commonly heard statements on the PBA and LPBT Tours is: "I do not care how I 'set up' that piece of equipment; it will not give me the ball reaction I need." Therefore, I suggest you find the ball designers whose products provide you with acceptable results and stick with them.

   NOTE: Please keep in mind that the effectiveness of any bowling ball, regardless of the player delivering it, is primarily based (75-80 percent) upon two factors; cover stock and surface preparation. That said, here are a few more frames of reference to further empower you.

Once you feel confident that you understand the 10 variables and the seven basic drilling techniques, proceed with the purchase of your next piece of equipment. The first four factors you should consider are hook rating, RG, RG differential, and surface preparation. These aspects are primarily contingent upon your particular speed-turn coefficient. If you deliver the ball at 12 to 14 miles per hour with 10 to 12 revolutions, a high RG, low RG differential is required in a 12-14 hook rated ball, highly polished.

Conversely, if you propel the spheroid down the lane at 17-19 mph, with 16-18 revolutions, a ball with low RG, high RG differential, and a 16-18 hook rating in a polished state is recommended.

Obviously, the lane condition in question can require variations on a theme; however, when the four factors herein are resolved, you can now decide upon the appropriate pin versus CG positioning, predicated upon the environmental requirements.

If the oiling procedure yields dry head areas with oily backends, you should utilize a pin and CG combination that allows for skid up front with a very strong back-end reaction (pin-out 1-1/2 to 2 inches, double or stacked leverage). At the other end of the spectrum, if the front ends are oily and the backends dry, you should use pin-in, placing the CM and the CG on your axis (P.A.P.). This would yield early hook with minimal backends.

If you encountered a condition where both the front and backends hook, you will need to place the pin in a label configuration, with the CG in a l/2 axis position (pin-out 5-1/16 inches), producing excellent length with moderate backends.

On the rare occasion when the front and back-ends are very oily, your only alternative may be an axis-leverage configuration (pin-out 3-3/8 inches), yielding early hook with a strong back-end reaction.

As you can readily observe, the task ahead is difficult at best, so proceed with caution. I believe that the most intelligent course of action is to align yourself with a teacher and a pro-shop operator who provide themselves with an accelerated comprehension, through intense study and analysis, of the contemporary facets of our sport, one of the most difficult to master. My book, The Pro Approach, might also help you come to a greater understanding of the complexities outlined above.

In the end, you cannot purchase success. However, enhancement of existing capabilities, through the implementation of technological advancements in bowling-ball design and drilling techniques, is definitely available.