It has some effect on how the surface bites the oil. Without adjusting the cover a bit, your ball will have some added length and a bit less move when it does make it's move on the back end. Doc (the person that used to make it) used to recommend sanding the ball to the next lower grit than the ball came with when NIB.
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"Whenever I feel the urge to exercise I lie down until the feeling passes away."
Brick