well ill try to explain it though mechanics arent my strong point. wrist strength plays a huge roll, before you roll a shot i suggest holding the ball with your fingers in it down by your side and cup your wrist. soo how long you can hold it before you have to let it collapse. if you cant hold it for at least 10-15 seconds, or however long it takes you to go through your approach on the lanes, you might need to strengthen your forearms. the key to it for me it to be able to do it just with your wrist, you want little if any muscle involved, the rest of your arm needs to be relaxed. as for your question about fingers/thumb exiting the ball, you always want your thumb to exit before the fingers. really what you are shooting for is to be able to collapse your wrist at the bottom of the swing, allowing your fingers to generate all the revs. sort of like cracking a whip is you can visualize it. the force of your wrist collapseing at the bottom transfers power and tourque to your fingers, which equal more revs. the goal is for the whole motion from pushaway to release to be fluid, no herky jerky motion. smooth is the name of the game. the best in the business at this is chris barnes. he cups in his stance, his hand opens up at the top of his swing, and really pay attention to how smooth he is at the bottom. i hope i havent consfused you too much, like i said i do it, but ive been doing it almost 10 years lol. it took me a long time to perfect it.
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