NEWARK, OHIO —Few elements of putter research have potentially revolutionized modern putter design more than the effects of Moment of Inertia (MOI). The MOI label and MOI ‘measurements’ have begun appearing on more and more putter heads, but offering little clarity to the facts behind all the numbers. However, the research and design team at The GolfWorks has now revealed extensive, test-facility research that sheds light on the relationship between the MOI of Low- and High-Moment putter heads and the effective sweet spot in putters.

At a recent seminar at the Professional Clubmakers Society, GolfWorks Vice President of Technical Services Britt Lindsey illustrated the effect of off-center hits with low MOI putters versus high MOI putters, and outlined the fact that the higher a putter head’s MOI, the better chance a player has to make putts.

Moment of Inertia itself can be defined as a measurement of an object’s resistance to twisting, explains Lindsey. The higher an object’s MOI, the more resistant (or harder) it is to get the object to rotate about its center. The lower an object’s MOI, the less resistant it is to begin its motion. The art of putting requires a golfer to strike the golf ball with a particular type of mass (putter head), and that mass should transfer the energy directly to the object targeted (i.e. a golf ball). Because no golfer can hit a golf ball perfectly every time, energy is lost along with distance and directional control.

The diagram illustrates the dramatic effect of an off-center hit. Using the sophisticated hitting robots and MOI test putter at the Maltby Design Studio, GolfWorks research struck a 22-foot putt with a contact point that was 3/4-inch offset. The high MOI putter (43.3337 oz-in2) rolled the putt closer to the intended line and closer to the desired distance on both the heel and the toe impacts. In fact, both off-center hits still dropped in the hole or resulted in an easy tap in. In contrast, the lower moment putter (29.8646 oz-in2) fell far short and did not stay on line. The ball stopped 52-inches short of the cup and right of the intended line on the toe hit, while the heel hit stopped 32-inches short of the cup and left.

Lindsey explains that many of today’s popular putters possess even lower moments of inertia than The GolfWorks low-moment test putter (29.8646 oz-in2). However, the test putter is significantly less than the high-moment test putter, which is at the upper limit for a 350-gram head weight putter. To put this into perspective, an original center-shafted bulls-eye putter has an MOI of 13.1753 oz-in2. An original Ping Anser Scottsdale,15.9859 oz-in2. The original Zebra by Ram, 17.5832 oz-in2. Based on GolfWorks research, the lower the moment, the worse the putting results.

For the first time in a many years, putter styles are becoming more extreme and performance parameters are being stretched. However, just because a putter looks unconventional does not automatically make it a High MOI putter that outperforms so-called ‘normal’ designs. The research and science behind the claims of High MOI are extremely important, and if clubmakers want to craft a putter that gives a player the best chance to make putts from any distance, they should for aim for the highest-possible Moment of Inertia putter.

“If all players hit every putt in the center of the face all the time with every putter type, MOI would not matter,” says Lindsey. “But golfers do not hit every putt on center, and using the highest MOI putter design possible will minimize the influence of less-than-perfect contact with the ball.”