What’s true—and what’s not—about what alignment stripes do for your putting

Under the dual headings of “Marketing People Just Want To Sell You Stuff” and “Golf Equipment Writers Who Recycle Manufacturers’ Marketing BUMF”, a recent article by an experienced and well-respected golf writer (whose BA in English Lit probably doesn’t qualify him to evaluate the dynamics and physical attributes of golf equipment) is promulgating more marketing nonsense from people who sell golf balls:

https://golfweek.usatoday.com/2023/04/12/callaway-chrome-soft-360-triple-track-golf-balls/

Callaway’s update to their Triple Track alignment aid system,

Triple Track 360, features blue stripes that now go all the way around the ball.

The article at the link above, about the new and improved Callaway 360 Triple-Track system—which now features blue lines that go all the way around the ball (that is, 360º – get it?)—states the following:

“(T)he two blue lines […] wrap completely around the ball, making it easier for golfers to aim the ball […] and to see if a putt is struck with a square face. If the lines stay smooth as the putt rolls, a player knows [they] hit the putt correctly with the face square to the target line. If the lines wobble as the ball rolls, the face of the putter was either open or closed to the line when it struck the ball*.”

This kind of stuff makes me weep.

The Triple-Track system, with a single rather heavy red stripe flanked by a pair of thinner blue stripes, was originally presented as a revolutionary upgrade over a single line as a static alignment aid, a quality that is supposed to be due to an effect called Visual Hyper Acuity (see: How Triple Track Technology Can Change Your Game). The effectiveness of “VHA” is said to have been certified by Dr. Carl Bassi, the Director of Research at the University of Missouri – St Louis College of Optometry, and also by Ray Barrett, an “entrepreneur and avid golfer” (whoever he is, and for what that’s worth).

I can’t speak to the effectiveness of Triple Track markings in helping golfers achieve micrometer-level alignment accuracy—vision science is not one of my specialties—but I can speak to its effectiveness in helping golfers assess the quality of their strike: it has none.

It’s very simple, and readily apparent to anyone who is familiar with the dynamics of impact and rolling objects: striking the ball with an open or closed face does not make the ball wobble, but the stripes may appear to wobble —which may appear to the uninitiated that the ball itself is wobbling—unless they are perfectly aligned with both the face and the path.

Face angle relative to path determines the direction that the ball heads immediately upon coming off of the face; “wobble”, as shown by the stripes on the ball, indicates only that the stripes were not aligned with the path that the ball started rolling on. If the ball starts to wobble later in the roll, that’s an indication that it hit some inconsistency in the putting surface and was thrown off line—but neither of these things means that the ball is rolling inconsistently—“wobbling”—due to having been struck with an open or closed face.

To help you visualize how this works, imagine slicing a section through the ball along the stripe to make a disc. That disc is like a coin standing on edge—if you roll it and it rolls true you will only see the edge of the disc-shape as it rolls away, like the illustration on the left, below. However, if the stripe is tilted to the path of the ball, the disc-shape described by the stripe will sweep a wider path as the ball rolls, like the illustration on the right, below, presenting a visual “wobble” even though the ball is rolling true to the path.

The only way to know whether the ball was struck with a face that was square to the intended path is to observe the ball’s roll relative to the intended line. Because the ball always leaves the club face on a path that is perpendicular to the face, observing the roll to note whether or not the ball starts on the intended path will tell you if face and path were square.

Watching a stripe on the ball as it rolls will only tell you if the stripe was aligned to the path when the ball started rolling, and that is pretty useless information.

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* (italics mine)

Is Cobra’s new 3D-printed putter the real deal, or just hype?

I just read an article on an online golf outlet about Cobra Golf’s new King Supersport-35 Putter, touted as the first 3D-printed putter. Unfortunately, like so many equipment “reviews” in both print and online golf media, this article reads more like a press release from the club manufacturer than a meaningful evaluation of the product. I have met the author of the article, and played golf with him, and he’s a very nice guy – but he’s not an engineer. I, on the other hand, am—a mechanical engineer as it happens, and I have just shy of 40 years’ experience in the design and manufacture of mechanical equipment, so I have the background to call out the club manufacturer, Cobra, on some of the claims that are repeated in that article.

The first thing that struck me as wrong is that this is not the first 3D-printed golf club to hit the market. Admittedly, the others of which I am aware are from much smaller boutique brands with very little market penetration; for example, Round4 Putters, which was making some noise online a couple of year ago but which seems to have disappeared from the landscape since then.

Callaway and Ping—both major manufacturers—have experimented with 3D putters. Back in 2015 Ping marketed a soup-to-nuts custom design and fitting process for a 3D-printed putter that would result in a personalized one-off putter at a cost of something like $7,000 to $9,000, but have yet to bring one to the retail marketplace. So Cobra are the first to bring out a mass-market (but still pricey, at $399 MSRP) putter, but not the first 3D-printed putter on the market.

On the technical side, Cobra states that 3D printing allows the formation of a latticework of metal that allows mass to be relocated from the middle of the head to the perimeter resulting in, they say, “the highest MOI without the need for additional fixed weights.” Now, it is true that that fancy-looking lattice structure would be extremely difficult to produce by conventional manufacturing methods, but is it really necessary? Or effective? Why not just hog that space out by CNC milling machine, removing the same amount of material, or even more, to get the desired effect?

You see, that fancy lattice isn’t structural; it doesn’t provide support for the upper portion of the club head, or stiffen the face of the putter—it’s just there to look fancy and justify the use of 3D printing. And while fixed weights may not be as sexy as a 3D-printed lattice, they are easily installed by conventional means. For that matter, removable weights allow adjustment of the mass distribution of the putter by the use of heavier or lighter interchangeable weights, yielding a wider range of performance and fitting options in the same basic putter head with very simple manufacturing methods.

To their credit, Cobra is utilizing a new, advanced 3D-printing method developed by Hewlett-Packard that delivers the precision and complexity of high-resolution 3D metal printing at higher production rates, and thus at lower cost, than the powder-bed fusion methods that have been used previously.

Rather than use a laser to sinter metallic powder layer by layer, HP’s 3D Metal Jet process “prints” a binding agent into a matrix of metallic powder, building up the desired shape a layer at a time. The binder is cured by a heat source, producing a high-strength “green” part which is then sintered (essentially, baked at high temperature to fuse the metallic powder matrix) to create the final part. After some cosmetic finishing and CNC milling of the most precise finished dimensions, as necessary, the part is complete. This process is faster than powder-bed fusion, and has been shown to produce more uniform material properties in the final part.

That’s all well and good, and there are any number of applications for which this process would be a manufacturing godsend—but does it really bring any performance advantages to the world of golf?

As I mentioned previously, the one real justification for the 3D printing process which is touted by Cobra’s ad copy, the internal lattice, is advertised as a means to increase MOI (it’s y- or vertical-axis MOI they’re talking about, which they don’t specify, but when considering the dynamic properties of a shape, it is important to know, and specify, which axis—X, Y, or Z— is being considered). Looked at realistically, however, the same mass distribution could quite easily be achieved by more conventional methods, so why bother with the whiz-bang 3D-printing method?

It all comes down to one word: hype (also “marketing”, which is far too often the same thing.)

Let’s face it—golf clubs, especially putters, being sturdy metal objects which don’t wear out quickly, and whose one wear-prone component, the grip, can be easily renewed, don’t support model turnover. Not, at least, unless the consumer can be convinced that the latest model will take strokes off your game by allowing you to hit the ball farther, straighter, with more precision (or some combination of the three).

Real, meaningful advances in golf club design are rare—the last one which really struck me as innovative and with real performance advantages was Callaway’s “Jailbreak” technology, which is kind of a hokey name for their use of a pair of vertical reinforcing rods which connect the crown and base of the head of a driver, fairway wood, or hybrid,  isolating the face so that it can do its job more efficiently by allowing the face of the club to flex and rebound without distorting the body of the club head.

So, to my rather cynical (but knowledgeable, if I say so myself) eye, Cobra’s new 3D-printed putter, while sexy and cool, and produced using a very interesting new manufacturing method, is just another hyped-up golf product that is being sold to the golfing public on the strength of some whiz-bang new technology, when it is really just a lot of smoke-and-mirrors marketing designed to generate another product cycle. It is another example of a golf club manufacturer selling golfers more new clubs they don’t need, when said golfers would benefit more from practice and instruction than they will from dropping a load of cash on the latest fancy new club design.