Okay here is the scenarion.

If you buy two balls that are exactly the same; Heavy oil ball (Example - Virtual Gravity).

You drill one for length and one to hook early.

Is there going be a big difference between these balls on lanes when thrown by the same person.

How much more length is that person going to see?

Does the oil pattern play a bigger part in this? Would there be a bigger difference on Long vs. Short oil pattern?

Yes you would see a difference and yes you would see more of a difference on different oil patterns.  as for the amount of length I would imagine that would depend on the individual axis tilt, revs, speed, etc.
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