Hey Nollster,
On the average, I usually give my customers a standard of 1/8 forward in the fingers for lift and adjust from there to either increase or decrease for personal feel(some guys use 0). Laterals are set at 3/8 and 1/2 in opposite directions, true parallel impression is supposed to be 7/16left - 7/16right per Bill Taylor.
Not sure if your release is in any way close to my cousins' but I'll describe it for you. He has quite a bit of hand rotation, almost 80 degrees. His thumb is also still in the ball as his hand rotates around it, if his wrist gives a little, his fingers will clip the ball on the way out. This is how he was getting his friction. I learned from a couple of other customers that the other thing I found consistent in seeing this bruise was if their wrist gave out at the point of release causing the ball to fall mainly on the fingers and if the fingers bent back, it created the friction from there. When I got them to stay under the ball a touch longer with their wrist, the friction went away per their response.
With this understanding, I also started increasing reverse pitch in the fingers to angle the finger in the weak wristed position so there was no longer any conflict.
If you have a good shop like you say you do, I'd recommend to go back and talk to them. I always welcome any of my customers with their questions or problems if something doesn't feel right. I can't tell you what you feel and not everyone can be the same, so that's why I'll try and adjust and tweak feels to individuals as needed for comfort. Hope this helps...
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Rick Leong
Ten Pins Pro Shop
Track Intl. - Amateur/Pro Shop Staff
Vise Inserts Staff