I am sure this has been discussed before, but I cannot find it, if someone can provide a reference, that would be great. Otherwise...

I spent all my practice time yesterday using three equally prepared balls (1000 sanded), 2 Motiv Raptor P7, and a Hammer First Blood (although that has little to do with the specific question). This had the side effect of enabling me to see the first oil ring very well. The three balls had very different layouts, and I was amazed to see the difference in location and track of the first oil ring. If I had to measure my PAP off of that oil ring, the results would not even be close.

Now, I have heard that the PAP is different for every ball. I also believe it is possible that the driller is simply not hitting the holes correctly, causing me to release the ball differently. I further acknowledge that a proper test would have been to determine the PAP and place tape at the position to check. Frankly though none of that really matters to the basic question.

If determination of PAP is based from the first oil ring, then my PAP would be dramatically different for every ball. Is this a function of the driller/spans/pitches, or is it a normal fact of your layout? Although I cannot really see the layout having that big a determination in the first oil ring, the differences were at least 1 1/4 inch between the three balls, with one being right next to the thumb, one at .75 inches, and another being almost 1 1/2 inches from the thumb hole.

I know I should know this answer, but I can't think of it...

Thanks
L50

If you think there are differences in the fit of the balls, the change in first oil ring position could be because of changes in axis tilt.  That will result in different first ring positions but with the same PAP.  --  JohnP

Use a plastic ball. Then as stated mark your pap with tape then have it confirmed by someone watching you.

Seriously? You don't seriously think that do you? The TRUE PAP is the release PAP which is the axis off your hand...this is what pin to PAP distance is designated from. There is a release axis and then migration.

Somewhat confused.

Why are we looking for his PAP off his hand at release ?  PAP is located down lane when the ball goes into a roll, therefore if the tape is marked correctly, then the tape will not move once the ball is rolling.  So, why does he need someone to watch him bowl to confirm the tape is not moving ?

What am I missing ?

PAP is found at the release point which is why you need to have someone watching or have a video camera on you. That way you can make sure the tape marked does not flicker/move upon release.