A few weeks ago, I promised that I would give a refresher on some of the basics of club design and fitting specs. Appropriate because we manufacturers spout off about Ai, high MOI, low, Deep CoG, etc., and it is often received with a blah, blah, blah. It might be nice to have a refresher course as this stuff comes into view.

So this week, let’s start with a few terms.

Ai

Ai is a design tool. It stands for Artificial Intelligence. In essence, it’s utilizing the power of a computer to accelerate the design process with input from human and data sources. It allows engineers to “think” outside the box – literally. At Callaway, we started using Ai in 2009, yet our first production club that used it in it’s design was the Epic Flash that launched in 2019. We spent 10 years playing around with this technology trying to figure out what to do with it. We have been using it longer than anyone else in this industry.

As a real world example, the face on the original Rogue driver was designed by an engineer and had 6 different versions before they finally settled on one face for the entire product line. The next driver model was Epic Flash. Using Ai, the team went through 14,000 different faces before finding the right one. This only led to a discovery that the face on the 9* head did not work (at all) in the 10.5* head since the face was so specifically designed for the body that the face sat in. So, the process restarted for each loft and model. 6 different face options to 14,000. That’s progress!!

Today, we use Ai to design faces (and many bodies) on every club we make – including putters with the Ai One. The Paradym Ai Smoke driver face went through roughly 50,000 face designs before coming up with the finished product. We have added optimization for every launch condition into our Ai programming, and, with Ai Smoke, we started to add player golf swings into the data that we use for design.

14,000 faces to 50,000 faces. That seems like a lot and it is. It seems like a big increase. It is, but it’s needed because the complexity of what we feed in to the Ai system requires more trial and error to get it perfect. “But how do you know when you’re done? How many face iterations is enough?” There is a point of diminishing returns. At some point, the design either can’t get any better, or it doesn’t look right, or it exceeds the capabilities of todays manufacturing. Design for the future is still dependent on what else we can do today. The USGA limits how much we can do. And… that finicky “golfer’s eye” – if it doesn’t look like a club that players find appealing, players won’t play it. We need some human intervention to keep the Ai on track. All of these will limit the ceiling of Ai – at least for today.

With Ai, though, simply having the computer power is not enough. It’s like fitting with a launch monitor if you don’t know what you’re doing – having all the information is meaningless unless you know what you’re looking for and how to use it. We are 15 years in with Ai. Ai helps our team be the absolute best it can be.

CoG

CoG stands for Center of Gravity. Typically, the lower we can make it, the higher the ball will fly. Also, the deeper we can make it (how far back from the club face), the more forgiving it is. With some players, we want as low and deep of a CoG as we can get (higher handicappers who struggle to get the ball in the air and who can’t consistently hit the center of the club face). While with others, we want the opposite (Higher, forward CoG) – think tour caliber player. There are many clubs throughout the line and each one has a different CoG location. Understanding this helps you put the right club in a players hands.

If the CoG gets too far back, the feel is soft or muted – not desirable for a good ball striker. Position here is critical for the feel and performance of the club head. This is the fundamental trade off in club head design – feel vs. forgiveness. As one goes up the other goes down – ALWAYS.

MOI

MOI stands for Moment of Inertia. Essentially, it measures a body’s resistance to twisting. The higher the number, the more the body resists twisting. Why is this number important? If you hit a ball on the TOE of the club, what happens to the face? It wants to open, right?? This opening will start the ball more off line, correct? It’s the equivalent of hitting a shot in the center of the face, but with an open face. Spins will be different, of course, but that’s a different discussion for a different day. If we (manufacturers) can increase the MOI of a clubhead, we can keep the club from twisting as much on off center hits. This is a feature that allows a shot to travel straighter when hit off the center of the face. For certain player groups, this can be VERY important, while for others, it’s isn’t even worth a mention.

We see this spec discussed mostly in drivers and putters, but it comes into play in everything. It can go too far, though. Too high MOI and the head becomes difficult to release or rotate. Different levels for different player types.

Let’s leave it at three for today, but as we think about these three, contemplate what Callaway does in design to effect each of these. Here are a couple of examples:

• The driver uses a 360* carbon chassis. This takes weight out of the middle of the body of the golf club. This allows weight to be repositioned forward and back (forward weight gives more or less weight around the outside to add or take away MOI (forgiveness), weight in the rear allows for stability (deeper CoG)). Hmmm making sense now?
• Micro Deflections in the driver face enhance contact on a wider range across the face – this is done with Ai.
• Ai Designed face in the Ai One putter. This simulates an increase in MOI without actually increasing it. We use a variable thickness, computer optimized face to control the direction of the putt when hit off center. Now that’s cool!!

As you look through the new product catalogs, you can begin to question “why would they do this or that?”. As you think critically, you can say “Oh, they did this to increase the forgiveness (as in the larger footprint of the Smoke Max D Driver). Bigger footprint = more mass out around the perimeter and further away from the ball = a wider and deeper CoG = more forgiving. Perhaps feel will suffer a little? I’ll have to try it and see what I feel.” Very good!! Or I love the taller/ deeper face on the Triple Diamond head. “Why did they do that? Hmmm. It’s not as deep. so the mass (CoG) has to be more forward. It’s taller, so the mass (CoG) has to be higher. It has a smaller footprint, so the MOI must be a little less – maybe not as forgiving. I bet it feels really good, though…” Now you’re getting it!!

A little knowledge is powerful. Use it to your advantage. Think about it the next time you pull a club for a player to hit during a fitting. You’re doing it with a purpose and a reason, rather than a “here, try this one. Let’s see what this does.”

Happy fitting.