xrayjay,
I don't think it's you matching up to a specific core, it's more that a symmetircal core is more forgiving and easier to drill. Think back to the old days....all drillers worried about label drill, leverage, etc.. No one measured anyone's PAP. It didn't matter. The balls were more forgiving to drilling mistakes (not that any driller ever makes a mistake...to all the pro shop owners on here
) and more forgiving to operator error. They also didn't make very dynamic moves on the lanes either. I think that is what you are seeing. I know my highest series came throwing the Hy-Road, a symmetrical lightbulb core. In today's world of dynamic cores, you have to have the PAP perfect and the drill matched up to a player's style perfectly, are you wind up with a $200 paperweight. I know most of us do it, but even coping the PAP from an old ball or an old drillsheet, could mean a new ball is drilled incorrectly. If you don't throw the ball the exact same way anymore, due to age, injury, coaching, etc......your PAP may be different now and even a small change can effect how a ball will roll. You almost have to take a PAP measurement everytime you drill a ball. A bit dramtic, probably....but JMHO.