im not fully sure about how to make changes to get semi or full roller i use to be one when i musled the ball on my old bowling style but took some time to get into my new release but about the bending of the arm in the backswing could or couldn't make you throw the ball in a spinner style cause i also have a bending arm in my backswing but i dont got the spinning i eather have a high track or depending on the lane i will adjsut my wrist for less hook make my track above my fingers but still come down beside the fingers on a angle.
but maby you could try some release drills where u stand the distance that u slid away from the foul line and throw your arma back and forward 3 times but on the 3rd time forwar u would throw the ball and on the 3rd time backwards u would do your step/slid and it helps with your timing and keeping your arm streght i did this for awhile till i got use to it but dont worry about putting any revs on the ball at first but then later on put revs on the ball, this might help not sure we will have to wait till bowl1820 posts he probly knows away.
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