The most important factor by far is to have the pin placed where you want/need it to be. The difference in thumb or finger weight will be so neglible that, if you threw it before and after, you would not be able to see it. Whereas, if you changed the pin position and threw it before and after, you would be able to see the difference. The effect of 1/2" of CG movement with respect to changes in thumb or finger weight and its final effect on dynamic cored balls can virtually be ignored.
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