I suspect that what you are actually seeing is a bigger move on the back end, which is what a polished ball will do versus a ball with a matte finish. The matte finish is going to give you a more even reaction, reading the lane a bit earlier than a shiny finish and hooking less in the back end.
Also, bowlers don't usually pick up (see) their ball right out of their hand. Depending on how far down the lane you pick up the ball, a polished ball will seem to hook more because it probably isn't even reading the lane before you pick it up. OTOH, the matte finish ball may start reading the lane (hooking) before you pick it up, so you could be missing part of the ball's reaction.
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RW (THB)
