--------------------------------------------------------------------------------
I have a Rule with 3-1/2 inch pin, drilled with pin above the fingers,on the center line. The cg is on the grip center and mb just right of the thumb.
whether dull or polished it just doesn't make a strong move on the back
unless they are freshly stripped, and then only for a few frames. The conditions are generally medium oil mostly flat,no area to the right. I am thinking this may be too mild of a drilling for this ball. My span is 4-1/4 and p-a-p is 5-1/4 over 1-1/2 up. If anyone has a suggestion I appreciate your help.

It sounds like you have the MB too close to your track for the ball to make an agressive backend move.  Your axis cordinates are close to mine and I have an X-Factor drilled similar to your Rule.  For me it put the MB about 6.5" away from my PAP.  This would be a very late hooking drilling and unless there were some backend the ball wouldn't make a huge move.  That and the MB ends up usually within the now suggested 2"+ range from your track.  If the MB was placed further away from your thumb...like 5" or less from your PAP the ball would've made a bigger move.
--------------------
-Chris: DJ's Pro Shop : Auburn, MA