Putters are built way too light to be effective. That’s a fact. 360g in a putter head are not nearly enough for an adult to properly swing the putter… and results in too much stroke and strike variance.
One of the best ways to look at this, from a pure physics perspective, is relative mass.
There are 4 different “mass” or weight factors to consider.
The weight of the ball (never changing), at 1.62 oz, or just under 46 grams in most cases.
The weight of the putterhead (by previous standards) usually between 330 and 380 grams.
The weight of the putter, overall, including shaft & grip, and sometimes, a weight plug high in the putter.
The weight of the player, especially that of his upper body (upper torso and arms).
Now, for a good example of what happens to an elite player who experiences proper weighting, compared to traditional putters, you can refer to Mr. Bob Dickson’s comment after putting with the Black Hawk… https://one-putts.com/2012/03/25/what-pga-professionals-say-about-the-black-hawk-black-swan-part-iii/
…took out my old putter for one round. The old putter is back in the closet – I’m pretty sure now it’s for good! The old putter felt like I was putting with the shaft only – no head on it.
Now, for an example… I was once a twelve year old, weighing perhaps 65 pounds, when I used my Bullseye putter for the first time. But as an adult of over 200 pounds (three times heavier) does still using a 350g putter head make any sense? Either the putter mass to player mass ratio was way too high then (it sure didn’t seem so at the time) or way too light now (the likely case).
The ratio of head mass to ball mass also is important. Now, diminishing returns kicks in, but a heavier head has an easier time striking the ball with a more effective momentum transfer. Why? Is it simply Newton’s classical Second Law “Conservation of Momentum”? Mostly… but there is more to it than simply that. You truly need to consider the impulse involved in the collision, the properties of the ball (and putter face perhaps) to get to the whole truth here… let’s simplify all that though… Newton’s Law explains why a heavier putter head can swing slower, and still strike the ball the same distance. That’s a good thing.
Now, about overall club mass, and location…
There is a company that sells putters that have a far heavier overall mass. It’s an interesting theory, from a marketing standpoint. You have to give them credit as marketers… they definitely exploit the inability of most golfers to discern between common-sense physics and simplistic (first order) “popular science” type thinking. Their theory? Adding weight high moves the balance point farther from the head. Supposedly this helps the “pendulum stroke” occur.
Interesting theory… unfortunately dead wrong. We prove it every day. Here’s why…
A “pendulum” swings effectively based upon it’s “radius of gyration”. That’s a fancy engineering term for the distance of the balance point away from it’s pivot in a pendulum device. Galileo figured out in 1602, that an “ideal” pendulum actually would have a weightless string, and a heavy bob.
Here’s an easy way to see it… try putting by swinging a sledgehammer from the wrong end. What happens? The (normal) grip end (simulated clubhead) swings all over the place, it’s tough to control, much less putt a golf ball. Now putt by swinging it with the hammer down… wow. Now that’s a pendulum stroke.
So, if you were blindfolded, I could place in your hands, either a so called “Heavy” putter (with backweighting), or a facsimile of one. The fake would be the same overall mass as the actual (Heavy) putter, but shorter, with a weight on the end of a (very light) stick, and the balance point the same distance from the grip as the putter. All I would need to do, was replicate overall mass & radius of gyration, and you wouldn’t know which was which. As a design engineer, such a device would be fairly simple to design, especially with computers doing our iterative calculations for us.
In either case, your stroke errors (angles, displacements, velocities, vectors) would be translated thru the CG of either object. Niether of which is anywhere near the ball. The consequence of such, is that the errors are “leveraged”, or magnified by the distance the the CG is away from the ball.
Not only does back-weighting make the putter “Less Effective” as a pendulum device, it increases the severity of the stroke errors you naturally will experience. Not a good way to putt better.
Bottom line? Heavier putters (where it counts, in the head) are more effective. But, in the grip end? Don’t bet on it.