NaSTI, the answer depends a lot on the lane conditions you bowl, the layouts on your equipment, cores, covers, your speed, revs, etc. Combining all of the variables can be tricky. I worked this out, once and for all, for myself and posted my strategy here. The link is http://www.bowlingcommunity.com/b/ubbthreads.php/topics/172968/4_Ball_Arsenal_Specs.html#Post172968
I have further simplified my stratgey by choosing one simple, optimimum layout. It is the same for all my equipment, symmetrical or asymmetrical. It places the Pin 3-3/8 inches from my PAP, and 6-3/4 inches from the center of my thumbhole. The thumb is then drilled through the mass bias marker. This layout produces near maximum flare for each ball. The goal is then to choose balls with different flare potential, in the range of 3-4", 4-5", 5-6", to ensure a varied arsenal.
PBA (2014-2015): $850
Heavy: Nano, HyperCell, Eternal Cell
Medium: IQ Tour, Tour SiC, Tag
Light: Spare+, Tank, Rebel Tank
Internet advice is offered free, as is, at your own risk.