Well yes you can, if cupping your wrist starts giving you pains or if its throwing off the consistency of your release then it might be too much. But cupping the wrist usually allows for more revs and a stronger release. If your comfortable with it and consistent/accurate then there is no reason to change. Or better yet...teach yourself to bowl with a cupped wrist AND a straight wrist. Each will have conditions that they match up better with. Versatility leads to greatness.
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-If you're not willing to change, you're not willing to improve.
-Life is like a coin, you can spend it any way you want, but you can only spend it once.
-I will forever love this great game, I love the people and the competition, I only wish the best would get the recognition of an ATHLETE that they deserve.