Can You Limit Yourself to One Ball? by Ed Cotter
Can you imagine limiting yourself to one ball? Probably not, but that is what the pros did in Dick Weber and Earl Anthony’s era. Pros now have 6, 8, 10 (possible more) ball arsenals that they cart around. I’m going to work at this as an old-time pro in a current pro’s world. I’ll be trying to select one ball that will cover most lane conditions from a stroker’s point of view.
The first thing to consider in ball selection is your style. This will determine what type over ball you’ll want to use. A cranker isn’t going to want a course coverstock (less than 1000 grit). The ball will roll out and lack the desired punch into the pocket. A stroker isn’t going to want a polished coverstock (3000 or higher). The ball will slide more than it hooks and will deflect more in the pocket. Croakers or tweeners (which ever you prefer) have a little more difficulty in choosing a coverstock. They have to also consider other ball factors in a manner that crankers and strokers don’t. I find polish the best way to smooth coarse balls. Then I only have to remove the polish versus having to find a ball spinner to sand the ball.
Now that you have your style, you’ll need to consider the coverstock. The main aspects to consider in a coverstock are the type of material and the finish out of the box. The types of current coverstock range from polyester (hard plastic little traction) to reactive resin to particle (pieces of broken material in the coverstock). The finish of the ball out of the box is important. Many bowlers try to rough-up polished balls and finely sand coarse balls. The problem is after about 15-24 games, the ball’s coverstock will start to revert to the original out of the box finish.
From a stroker’s perspective, I then consider ball dynamics. The dynamics I would consider are radius of gyration (RG), differential (Diff), pin placement (PP), and center of gravity (CG). The lower the RG (2.48 or lower), the less effort required to have an unstable ball rotation move to a stable rotation, a.k.a. flip. The higher the Diff, the easier it is to start the RG on its way to a stable rotation and the greater the flare. PP is important in helping to create an initially unstable weight block position. The further the PP is from the CG the greater the capability to create an initially unstable weight block. The more unstable the weight block is when the ball first starts rolling the more the ball will hook and turn to arrive at a stable weight block position.
http://www.bowl.com/articleView.aspx?f=21&i=12811 (bowl.com article on radius of gyration)
http://www.bowlersparadise.com/help/faq/balls/specs.shtml (Bowler’s Paradise list of bowling ball term definitions)
http://www.currahee-usbc.org/korner/rg_diff/index.php (Currahee USBC of northeast Georgia explanation of radius of gyration and differential)