Martin, just so we're on the same page, drilling refers to the layout on the ball not how well it fits. Where I saw a big difference in ball reaction was when I drilled a ball with the pin on my pap vs a ball drilled 4" pin to pap. Definitely more than 10% difference between balls. IMO the percentages are general. I think how a person throws the ball changes the percentages.
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Dick
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So many questions, so little time but I'm having fun.