Dear Walter,
People's bodies differ, especially the mass of the arms and hands, the angle of the forearms at address, and the combination of bend and head-neck position. A heel-shafted putter has the mass of the putter head farther out from your hands and feet than a center-shafted putter (about 2 inches), plus the heel-shafted putter has the head weight canter-levering toe-downish off the hosel at the heel. A putter that is farther out from you on a more slanted line from your hands, plus the canter-levering, tends to torque the putter handle inside your grip. This increases pressure on the top half of the inside of your hands (especially the thumbs). Most people relate "feel" in the hands to the thumb-index finger portion of the hands, as this is the key part of the hand used daily, especially with tools and common household and office objects. Golfers rarely relate "feel" in the hands to the inside of the last three fingers (the bottom half of the grip). This relationship is not optimally conducive to allowing ther hands and arms to hang. most golfers with a heel-shafted putter have some bend in their elbows so that the putter is held "out there" above the ground, and the shape of the arms and hands has a significant tension built in during the stroke.
In comparison, the center-shafted putter sits on the ground a little closer to your feet, so the weight of the putter head is suspended more directly down from the hands in comparison to a heel-shafted putter. The "flutter" that you refer to is probably the lighter tension of the handle due to less torquing against the top half of the insides of your hands. This sort of makes the putter seem lighter to people not used to FULLY hanging the arms and hands, as most heel-shafted using golfers are not. So the golfer used to a heel-shafted putter has tension in the arms and hands in the setup expecting the canter-levering head weight and the need to "hold" the putter in its place, but the center-shafted putter and its relationship to the hands undercuts these expectations. The golfer then seems to feel the putter as "light" and the normal muscle activation during the stroke moves the putter too much, which seems like a flutter.
The answer for you, then, is two-fold: learn to relax your arms and hands more before starting the stroke, and get a heavier putter head for the center-shafted putter. You will also have to learn to start the putter back with the shoulders, not the arms and hands, as the arms and hands will "lift" the putter too much and cause it to wander in its path. If you "unweight" the putter from the earth (as Nicklaus says) by SLIGHTLY breathing in to lift your whole upper torso just a bit and thus hoist the putter off the dirt onto the spongy grass perhaps 1/16th of an inch before starting the stroke, that will help smooth out the takeaway and shift the responsibility for this start to the shoulders (lead shoulder shoving sole of putter back). The trick will be for you to learn to leave the putter head down there suspended beneath the pivot of the base of your neck. let gravity fill your forearms and let blood fill your hands before you start the stroke back with a shoulder move.
Let me know how this works for you.
Cheers!
Geoff Mangum
Putting Coach and Theorist
PuttingZone
http://puttingzone.com
Golf's most advanced putting instruction -- you're either in the PuttingZone, or not.
