To measure tilt, you trace the first oil ring all the way around the ball. You take the prosect, and measure the diameter across. People with low tracks are going to have short diameters and people with high tracks will have longer diameters. The distance is what we call Track Circumference. We have a scale that translates the T.C. into degrees of axis tilt.
You can pretty much determine axis rotation with your naked eye. Bowlers who roll the ball end over end have 0 - 10 degrees A.R. Average axis rotation is 30 - 45 degrees. Bowlers that really get around the ball in order to push the ball cleaner through the heads and get more backend reaction are more in the 70-80 degree area.
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Steven Vance
Former Pro Shop Operator
If anyone out there is worried about the scores being too high, try duckpin!!
