I've gotten some comments from other reviewers from ths site, regarding the RC or the mass bias indicator. Wel, here it is: In any ball from any manufacturer, if the ballhas a mass bias indicator, the c.g. location is not much of a factor, as long as it's in the right "zone." The mass bias indicator's are known by several names. In Mo-rich balls, it's the RC or reaction center. In Storm balls, it's caled the MC2, Faball, it's the hotspot. As you can see it's just a different name, same animal..=) As far as i can tell, only mo-rich has a drilling layout with the c.g. zone and has a precise measurement of the distances between mass bias, pin and PAP. Perhaps I should also clear up the c.g.ZONE. It's that specified "area" on the ball in which the c.g. should be located after thye ball has been drilled. It's really driller friendly. Just log on to the mo-rich website, it''l clear things up.=)