I've read an article from 2012 I think from Blueprint regarding flare potential of bowling balls. They picked three balls (strong asym., medium asym. and a symmetric) with high differential ratings. It seems to me that if one wanted their ball to flare well they'd pick a drilling angle of 50 degrees. For an asym. ball they'd pick a pin to PAP distance somewhere between 4 1/2 to 5 5/8ths and for a symmetric ball 3 3/8ths. For a VAL angle they'd pick one on the lower end of the scale like 25 degrees. This would be a 2:1 ratio of drilling to VAL angles. Am I understanding this correctly?
I just had two balls drilled recently and their layouts were pretty close except one was an asym. and the other was a symmetric. The two balls were the Dark Legend and the Wreck-It. The Wreck-It seems to have a stronger back end. My guess is that I should have asked the PSO to take the VAL angle down from 50 degrees to 25 or 30 degrees on the Dark Legend and increase the pin to PAP distance from 4 to 5 5/8ths or so. Then the Dark Legend might have had the flare advantage... Hope I'm on the right track...
I think the link below may be the one you are referring to.http://blueprintbowling.com/Documents/Bowling%20Ball%20Track%20Flare%20Explained.pdf
However, be cautioned on making personal decisions based on the general findings. The tests were intended for illustrative purposes, for a particular set of release specs, with particular bowling balls, and may not be flare safe for other bowlers, or static legal without an exceptionally long or short Pin, or without adding a balance hole.
For my preferred layout, based on my release specs, I have found it easy to accommodate various balls in the typical 3-4 inch Pin to CG range, with 2-3 ounces top weight, with a balance hole being optional rather than mandatory. And, in Blueprint testing, it typically outperforms other layouts.
While Blueprint is useful for seeing general trends, it is most valuable when you plug in your particular grip and release specs, the particular ball you plan to drill, and the oil pattern you plan to use it.