I bowled last weekend, and the lefties that were around me had nothing. Looked like 10 out was slicker than snot.
I didn't see any lefty try to get waaayyyy left and go up the crack, we could get it off 1-2 on the right side if you got it out there quick enough.
I would go with it shiny how you like it, especially if you like playing deep. I don't know if you are allowed to scotch brite during practice or not, we are allowed to in PBA. If so, you can know some shine off, you get 10 minutes of practice during team event.
Hope this helps ya....
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