One of the sensitivities of pin placement is how much natural length you get from your delivery. This involves such characteristics as ball speed, axis tilt, PAP (and therefore track location) and hand rotation at the release point.
These make your ball try to go into a roll sooner or later depending on the degree. Thus they require your pin to be closer or further from the PAP and high or lower with respect to its height above the midline (the line between fingers and thumb hole perpendicular to the grip line).
Higher ball speed needs pin closer to PAP rather than further and a lower pin.
More axis tilt means you get more natural length. So you need lower pin and possibly pin closer to PAP.
More rotation means more length and more backend (usually). So you may need a combination of lower pin with pin further from PAP.
And all these are respect to the same type of ball, like your Horizon Solid. The good thing is that your Mystic has the same core; so comparisons are easier but still not simple than if they had different cores as well as different coverstocks.
As you can see, once you start combining these factors, you need someone who can balance them against one another to get you the best pin (and MB) placement to get the best reaction from your ball based on the condiiton and lane surface on which you'll bowl.
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"None are so blind as those who will not see."
