subject: Golf Hybrids and Irons [print this page] One of the most significant putter head design features is the Moment of Inertia (MOI) of the putter about its vertical Center of Gravity (CG) axis. The MOI about the vertical CG axis is the design parameter indicating how far the ball will travel when impact occurs off-center as compared to the distance for a putt hit on-center at the same stroke speed. The higher the MOI, the more resistance to twisting on off-center hits.
