Clubmaker’s Calculator

Insights from the Clubmaker’s Calculator

What you’ll discover with the Clubmaker’s Calculator is that the BtF and DtB ranges of your irons are relatively large—likely around 1.8 inches and 3.5 inches, respectively.

These ranges mean the geometric conditions at address and impact vary significantly throughout your set. In turn, this affects your consistency because there is a specific BtF and DtB combo that is your “sweet spot.”

Clubs at one end of the bag or the other are going to be a considerable geometric distance away from this sweet spot, and you are less likely to be consistent with these irons. (In fact, you’re probably already thinking of your “problem clubs” now!)

Considering golf is largely a game of precision, it’s shocking that our tools introduce this much additional variance to our address and impact conditions.

You can use this calculator to determine ways to reduce this variance within your own set of clubs. I like to call this geometric optimization.

Single-length or Custom-length Irons?

By now, you’ve probably heard of 2015 US Amateur Champion Bryson DeChambeau and his single-length set of irons. He lauds his equipment setup because it allows him to swing each club the same way—along the same plane, standing the same distance away from the ball, and with the ball positioned in exactly the same place in his stance.

Obviously, Mr. DeChambeau is attempting to reduce the variables presented by his equipment so he can focus more on the variables presented by the golf course. His remarkable success is a testament to this approach.

But single-length irons aren’t for everyone. Not only are they expensive to build, but they also require the significant reduction of weight from shorter irons and wedges and the significant addition of weight to longer irons.

The good news is that you can still drastically reduce the variables presented by your own clubs by taking a custom approach to club lengths and lies.

Better still, you can use this calculator to narrow your BtF and DtB ranges throughout the bag, and this will promote more consistent address and impact conditions with every club.

Recommendations for Clubfitting with Geometric Optimization

Based on personal experience, I recommend trying to tighten your BtF and DtB ranges as much as possible. In order to do this most effectively, you first need to drill down on your optimal BtF and DtB values.

For example, for someone with a 34-inch standing WtF, the optimal BtF is probably in the neighborhood of 32-33 inches, and the optimal DtB is likely between 16 and 17.5 inches. The clubfitter’s challenge is to tighten BtF and DtB ranges around these sweet spot values.

But why have a BtF or DtB range at all? Why not set up all your clubs to have the same BtF and DtB?

First, due to the different head weights throughout a typical iron set, different shaft lengths (and thus lie angles) are necessary to achieve either swing weight or MOI matching. In other words, unless you have iron heads that are all the same weight, you must have BtF and DtB ranges greater than zero.

Second, all clubs experience an impact phenomenon known as shaft droop, and the longer the club, the more pronounced this effect. This means that if your BtF and DtB distances were the same with every club, the toe of your heavier clubs would be slightly lower than the toe of your lighter clubs at impact.

To mitigate this effect, you need slightly greater BtF and DtB values with your longer clubs. Ideally, you would seek to reduce the BtF and DtB ranges to the point they precisely accommodate shaft droop—and nothing more.

Want to Chat about the Clubmaker’s Calculator?

Check out the official thread on the Clubmaker’s Calculator at GolfWRX.com.