WOW!! Lot’s of questions about Square 2 Square. Interestingly, I received several questions around Drivers? Like “Could you do the same technology in a driver?”, etc. It sparks some good discussion.

The short answer is we already have this – sort of. In the full swing world, we call this MOI – or Moment of Inertia. MOI is a bodies resistance to twisting. Kinda what we talked about last week, eh? There are differences. With a putting stroke, the speed of the stroke is much slower than a full swing, so the measurement is not really related. In English, you won’t see the effects of torque on the shaft of a putter since we swing it at 1-2 MPH. However, the head will still rotate on off center hits, making this is similar to MOI in a driver head. So, here is what we know…

In either a putter strike or a full swing strike, gear effect comes into play when a shot is hit off the center of the head (read: sweet spot). Here’s what happens in that collision. Say the shot is off the toe for a RH Player. Looking down, the driver head rotates clockwise (what we would call open). This will start the ball to the right of the swing path. The ball will get spin imparted in the OPPOSITE direction – in this case, counterclockwise or “hook spin”. If you’ve ever hit a driver off the toe, you know what I’m talking about. Complicating things are bulge and roll on the clubface. As you look at the face, you’ll see that the face curves to look open (pointing right for a RH player). This HELPS the ball start further right. As a manufacturer, we study this and calculate how much curvature we need to put on the face to make the resulting shot finish closer to the intended swing line when struck off center. The more violent the collision, the greater the influence (meaning a putter strike won’t be as effected nearly as much as a full swing strike with a driver or an iron).

If the face isn’t curved as much, the ball won’t start as far to the right (in our example above), but it won’t have any less counterclockwise spin imparted on the ball. This means it will start closer to the swing line, but finish further left. If you take this to a flat face, you will have a shot that starts on the swing line and spins left. Wait… a putterface is flat. Hmmm. Imagine if you could hit a putt off the toe and NOT let the face twist. Add a little hook spin to take some of the break out of a slice putt. Great idea!!

Not so fast. Before you let your imagination run wild. There is a difference between a putt and a tee shot with a driver – the ground. The ground adds a tremendous amount of friction, and removes a lot of spin, while the air doesn’t do that. Most spin put on a ball from a putter is gone about 18 inches to 3 feet after impact. Because of this, the playing field is different for a putter relative to a full swing club.

Now, also in a driver, there is a correlation between Fast and Forgiving. By fast, we mean club head speed OR ball speed. By forgiving, we mean how straight does it want to fly. The more forgiving a head is, the slower it is. If you want to hit it straight, you won’t hit it as far, and vice versa. To hit it straight on a mis-hit with a driver, we can do several things. We can make the sweet spot bigger (this makes the MOI higher, and is how everyone else does it), or we can use AI to create a smart face that makes the ball go straighter on off center hits (there is minimal loss in ball speed, and this is how Callaway does it).

So, let’s go back to the original premise. Can you make a driver that keeps the head square. The answer is sure – IF you can make a shaft that doesn’t twist (so 0* of torque and no twist). It would feel terrible, and wouldn’t kick, so it wouldn’t go anywhere. Now, let’s suppose you wanted to increase the MOI to greatly reduce twisting. To do this, you move the Center of Gravity deeper in the head, which makes the sweet spot larger. The larger it is, the less the head will twist on hits away from the center of the face (because the sweet spot is so big). When the sweet spot gets bigger, it gets more dissipated. When that happens, there is less energy transferred to the ball, so the ball speeds that result are slower. That is how you trade FAST for FORGIVING in a traditional driver head. In a nutshell, you wouldn’t want to have a zero-torque driver head. Sounds cool, but it wouldn’t be very playable. Super straight, but not as long as a three wood. Unfortunately, we manufacturers have to leave it up to the player to have some skill to make the ball go straight. 😉