kick12x,
RG gives indication as to how well the ball will get down the lane. This is normally the situation, but some balls have a very strong cover over a core with a high RG. High RG numbers usually mean the ball will get down the lane well, lower RG numbers indicate that the core will want to reb up quickly. Just remember.....coverstock is going to play a huge part here.
Hook potential: This is just as it states, how much potential the ball has to hook. You would want to look and see what the company suggests the ball to be (heavy oil, medium oil, light oil etc...).
Diff: This number indicates the difference between the ball's high RG and low RG. Usually the higher the Differential the more flare potential.
I hope this helps,
-EX-
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C-G Pro Shop (owner/operator)
Youngstown Ohio
Track Intl.-Amateur/Pro Shop Staff