Pin Position, before drilling, is the distance from the Pin to the Center of Gravity. Different lengths lend themselves to different drilling options and reactions.
Pin Position, after drilling, is the distance from the Pin to your PAP(Positive Axis Point)
Top Weight is weight concentrated at the top of the ball. When you drill out the fingers, top weight compensates for the material removed to help the ball retain balance.
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The clock on the wall says 3 O'Clock...last call...for Alcohol!