Smash Index & Spin Index: Two Game-changing Golf Metrics
If you’ve ever wondered how well you’re really striking the ball, or why some shots don’t spin as much as you expect, Trackman’s newest parameters—Smash Index and Spin Index—are about to change the way you analyze your game.
These new Trackman numbers go beyond traditional Smash Factor and Spin Rate, helping golfers of all levels understand contact quality, energy transfer, and spin efficiency in a much clearer way.
Let's break down what these metrics are, why they matter, and how they can help you hit the ball more solidly, control your spin, and shoot lower scores.
You can also watch the Trackman Talks webinar recording covering this very topic. Check it out at the bottom of this article.
WHAT IS SMASH INDEX?
You might know Smash Factor—the number that tells you how efficiently you’re transferring energy from club to ball. But here’s the problem:
Smash Factor is great for drivers but hard to interpret for irons and wedges.
There’s no standard for what a “good” Smash Factor is beyond the driver.
It doesn’t tell you how well you struck the ball relative to what’s possible.
Smash Index fixes that.
How it Works
Smash Index is a simple, normalized measurement of how well you transferred energy based on what’s possible for your club and swing.
Smash Index = (Your Smash Factor) ÷ (Expected Maximum Smash Factor)
A Smash Index of 100% means you hit the ball as efficiently as possible. Anything lower means you lost some energy—likely due to off-center impact, excessive spin loft, or poor contact.
Why Smash Index Matters
Gives you a clear, universal scale for energy transfer across ALL clubs
Helps you diagnose poor contact and off-center strikes
Makes it easy to compare ball-striking consistency over time
A Real-world Example
Let’s say you’re hitting a 7-iron. Your Smash Factor is 1.32. Is that good? Bad? Somewhere in between?
With Smash Index, you can see that your 1.32 Smash Factor = 97% Smash Index, meaning you left a little speed on the table. Maybe you hit it slightly thin. Maybe your contact was off-center. Either way, you know there’s room for improvement.
WHAT IS SPIN INDEX?
Spin is a tricky part of the game, and we suggest you have an understanding of Spin Rate before continuing.
We all want to hit high-spin wedges that stop on a dime, but knowing how much spin you “should” get has always been a guessing game—until now. Spin Index gives you a clear answer.
How it Works
Spin Index measures how much spin you actually generated compared to what’s expected based on your swing.
Spin Index = (Your Spin Rate) ÷ (Expected Spin Rate)
A Spin Index of 100% means you got the exact spin you should have.
Anything below 100% means you lost spin (often due to poor contact, moisture, or grass interference). Anything above 100% means you generated extra spin (thanks to high friction, clean grooves, or gear effect).
Why Spin Index Matters
Tells you if you’re getting the spin you should be
Shows the impact of wet conditions, rough lies, and gear effect
Helps you adjust your short game strategy based on real data
A Real-world Example: Victor Hovland’s short game transformation
In 2019, Victor Hovland's wedge shots had a Spin Index of 68%. This means he was losing over 2,000 RPM of spin. After changing his technique in 2023, his Spin Index jumped to 105%—giving him much more control and stopping power. Increasing Spin Index can be a complete game-changer.
HOW THESE NUMBERS WILL CHANGE YOUR GAME
For Full Swings
Smash Index helps you hit the ball more solidly. If your Smash Index is low, you’re losing energy somewhere—maybe due to poor impact location, spin loft issues, or clubhead properties.
Spin Index helps you manage launch and spin. If your Spin Index is low, you might be hitting it from the rough, dealing with wet conditions, or not striking the ball cleanly.
For Wedge Play and Short Game
Stop guessing about spin loss. If your Spin Index drops when hitting from the rough or wet grass, now you KNOW why your ball isn’t checking up.
Dial in your feel. Spin Index teaches you what conditions affect spin the most, so you can choose the right shot and club for every situation.
FINAL NOTES
The introduction of Smash Index & Spin Index is one of the biggest advancements in golf analytics in recent years. These new numbers will help you strike the ball better, control spin more effectively, and make smarter decisions on the course. Up to their release, you can check out the recorded Trackman Talks webinar session on this topic, so you're ready to get the most out of these new metrics.
Trackman Smash Index & Spin Index are coming for TrackMan 4 and TrackMan iO in Spring 2025.
WANT TO DIVE DEEPER?
To discuss these new metrics, Trackman’s Frederik Tuxen and Niklas Bergdahl recently hosted the inaugural session of a new webinar series: Trackman Talks. In case you missed it, you can, of course, still watch the full Trackman Talks webinar recording.
This Trackman Talks webinar recording will take you through:
Golf performance analytics using Smash and Spin Index
Exclusive insights directly from Trackman R&D via Fredrik Tuxen
Cutting-edge technology that will transform your approach
FAQ session on these new metrics
Trackman Talks: Master the Smash Index and Spin Index
Stay tuned for more Trackman Talks sessions, covering topics like putting performance, strokes gained analysis, and wedge spin optimization. Coming soon!