# Mike's questions

Dave Tutelman -- December 27, 2014
This work was instigated by a couple of questions asked by Mike Stachura. He wanted to know how many yards of driving distance you get for every mile per hour of clubhead speed, and also how many extra yards of driving distance could a golfer pick up without increasing clubhead speed.
In early December of 2014, my friend Russ Ryden put Mike Stachura, technical editor for Golf Digest, in touch with me. Mike had a couple of questions, and Russ thought I could help him answer them. The questions both deal with driving distance and clubhead speed:
1. Is there a simple multiplier to relate driving distance to clubhead speed, something like "distance = 2.5 * speed"?
2. How much driving distance does the average golfer "leave on the table", assuming his/her clubhead speed is what it is and won't increase?
This article answers the first question, and most of the second. The executive summary on this page is a spoiler, for those of you who only want the answer. For those who are interested in both the answer and how to get it, move on to the article itself.

Notice: I'm not going to respond to objections or questions -- nor general disbelief -- if you only read the executive summary. Your question might be answered in the article; read it first and then get back to me.

## Executive summary

### Question 1 - A simple formula for driving distance

There is a good answer to the first of Mike's questions, but:
• It is not in the form he assumed. It does not consist of a single multiplier, but rather a straight line that does not pass through the origin.
• It only applies to a restricted case. The restrictions include an optimum smash factor and a loft-optimized driver, among others.
The formula, fitted to computer-generated data, is

Carry distance = 3.16*speed - 85.2

But Mike wanted total distance, not just carry distance. Here's a best-fit straight line.

Total distance = 3.16*speed - 50.5

### Question 2 - How much distance does the average golfer leave on the table?

We come up with five ways the average golfer can increase driving distance without needing to increase clubhead speed. The example we used is a golfer with an 86mph clubhead speed. We discovered 30 extra yards -- 15% of his potential yardage -- to be reclaimed. Here are the things to do to find those yards:
 What we did Carry distance (yards) Improvement (yards) Cumulative improvement Baseline 171 -- 0 Improve impact to maximize smash factor      from 1.41 to 1.48 183 +12 +12 Fit the right loft from typical 10.5º 189 +6 +18 Increase attack angle from 0º to 2º 193 +4 +22 Lower clubhead's CG by 0.1" 195 +2 +24 Raise impact on the face by 1/2" 201 +6 +30

This was done for carry distance. Mike wanted total distance, so it doesn't fully answer his question. I will re-work it once I have tools that can generate a launch space for total distance.

On to the details, if you're interested...

Last updated - Jan 15, 2015