Should you switch to a belly putter?

Q: I am looking into a belly length putter but am unsure if I will like it or not. Can a belly putter head be reshafted to a regular shaft length?
-- Ben Schluterman, Fort Smith, Ark.

A: Generally a belly putter has a heavier head than a normal putter, so if you like a heavy head on the putter then you can switch shafts. Why don't you try a belly putter first in the shop or demo one. That way you'll get some idea whether you like it or not. From a technical standpoint, a belly putter is one way of decreasing the number of variables in the actions of making a putting stroke. This is sometimes referred to reducing the degrees of freedom (of which there are five in the traditional and common putting stroke). The long putter also takes the shoulders out of the equation, leaving only the forward/back and the outward/inward variables.

Q: I just got through reading your article in the September issue. I thought MOI was the technical term for the "sweet spot." So the term high rather than large confuses me. What is the technical term for "sweet spot"?
-- Laurence Colony, Venice, Fla.

A: The sweet spot on the face of the club is the point at which, if impact with the ball occurs, the head will not twist during or after impact because of what is known as central impact. The centers of percussion of the two colliding bodies and the contact point are in a straight line. The feeling transmitted to the hands is only in the slowing down of the head without rotation and it certainly is "sweet," unlike what we experience with an off-centered shot. A large MOI will reduce the twisting a little and consequently what we feel on those mis-hits, hence a larger sweet spot. Unfortunately, true central impact doesn't really occur during a golf shot because the head has loft which putts spin on the ball and in turn must twist a little to do this. But we do get fairly close to this and it happens when impact is on what we call the sweet spot. Hope this helps.

Q: I read your statement in the latest issue of Golf Digest that by wearing a golf glove the swing weight is reduced by 3 points. I never heard of that, Assuming that my "feel" is finely tuned enough, would that mean that if I were to find a good feeling club in a golf store, by hitting into a net without a glove, I would have to order a similar set with a swing weight 3 points higher if, when actually playing I always wore a glove, in order to experience the same feel on the course? Also, if the standard swingweight of stock clubs is D-3 as an example, and since most golfers wear gloves, the true swingweight would be D-0?
-- Buddy Thurman, Atlanta

A: What this shows is that we are not really able to detect these small differences and that swingweight should be used as a general guide. When shafts and grips all weighed the same the swingweight was totally dependent on head weight and shaft length. Today, because golfers insist on a specific swingweight, manufacturers will add weight down the shaft into the hosel or by some other method to make the scale read what the golfer wants. Major differences in swingweight will require a different weight head, or in some cases a change in the back insert of the head to adjust the weight. A shaft change will also have an effect on swingweight. A lighter shaft will (with all else being equal) have a swingweight that's lighter. Swingweight tells you nothing about the shaft flex though, which is a very important part of determining how a club feels dynamically.

Once you find the correct dynamic fit for you then you need to take a whole bunch of measurements - swingweight, overall weight, shaft flex, flex point and club frequency, just to name a few. Or, just get the standard set with a standard balance, which the manufacturers have worked so hard and so long to find suits most of us. This set comes in different shaft flexes - regular for most of us is OK unless you swing faster than 90-mph with your driver. Then you may want to consider a stiff flex. But don't worry about your glove, it really won't make that much difference.

Frank Thomas, former USGA technical director, is now chief technical advisor for Golf Digest.

Do you have a question or comment for Frank? Send your inquiries to equipment@golfdigest.com with the word "Thomas" in the subject field. Frank will answer the best questions in this space.

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