I know that MOI is a measure of how forgiving an iron head is on off-center hits.  And i see that is part of the formula to determine the MPF of a clubhead.  Is there any direct correlation between MOI and MPF?  In looking 3 irons that I have played in the past, Maltby MTF, Ping Eye2 and CER 851, I see that the value of MPF and MOI for each head is: MTF 788 and 12.5285, Eye 2 724 and 13.7826 and CER 851 919 and 12.1082.  Would I be correct is assuming that based on these figures that the CER 851 would have the least forgiveness on off-center hits even though its MPF value is the highest.  I love these heads and I always felt it offered more forgiveness than the other 2 designs.

I read on one of Ralph’s postings that it takes a change of 150 points in MPF to really notice the difference in forgiveness.  What change in value for MOI would it take to notice a difference?