I have 4 16lbs and 1 15lbs. I feel a bit of a difference in the weight (ball speed primarily, but not timing, technique or feel). The only thing I have to remind myself is to not muscle the ball, and to maintain the same speed (or really close) as to what my 16's travel. As far as timing, that will only matter if you REALLY muscle the ball through at the release...that one pound DOES make a difference when it's travelling through at 24MPH versus 16MPH. Momentum increases as a piece of mass times velocity. As velocity increases, the change in momentum increases at that same factor. So, with a 24MPH velocity at release, the momentum with the 15 and the 16lb ball have a greater difference than than the momentums at 16MPH. If you are one with a huge ball speed, this might create a problem. However, if you don't have a large ball speed, it's not so much of an issue.
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