Putting green speed is one of the more polarizing topics of discussion in our industry. The original intent of the Stimpmeter was to help courses achieve consistent and appropriate speeds for their greens, but as expectations have increased, speed has become an obsession at some courses. Fortunately, advancements in technology and tools now make it possible to quantify other equally important putting green performance metrics so we can look beyond green speed.
Having a well-struck putt bounce offline is infuriating and can put a sour note on an otherwise great round. Until a few years ago, measuring smoothness (up-and-down movement) or trueness (side-to-side movement) of a green was done subjectively. The GS3™ smart ball now makes it possible for superintendents to easily quantify these metrics and better understand the impacts that surface management practices like mowing, rolling, grooming, brushing and topdressing have on ball roll.
Firmness can also be measured with the GS3. USGA agronomists had been using an older tool to measure firmness at USGA championships since 2005, but switched to using the GS3 in 2023. Moisture levels and physical properties of the rootzone – especially organic matter content – play a major role in being able to deliver firm playing surfaces.
Collecting firmness data regularly makes it possible to analyze how moisture levels impact firmness. With the availability of the new USGA Moisture Meter, moisture and firmness data are available in the DEACON® management system to monitor trends. Tracking this information along with yearly organic matter checks, adjusting irrigation practices and refining cultural management programs can help balance turf health and improve firmness.
Surface strength also has an influence on putting green firmness. A stronger playing surface resists the impact of a golf ball and will play firmer than a weaker playing surface. Ball marks are a good indicator of surface strength. A small dent or bruise indicates a strong surface and a ripping, tearing or exploding ball mark signals a weaker surface.
A shear-strength tester can be used to quantify surface strength. I have used this tool for a few years and observed how grass type, organic matter levels and the timing of cultural practices impact surface strength. However, there is still more to learn about how to manage this metric and why it fluctuates throughout the golf season.
With the ability to quantify other putting green performance metrics that are equally (if not more) important than speed, it is time we look beyond speed and expand the discussion to include firmness, surface strength, smoothness and trueness. Collecting this data not only helps guide agronomic decisions, it is a valuable communication tool. The Green Section Record article “The GS3 Ball: Understanding the Numbers” provides an in-depth look at collecting data with the GS3. Reach out to your regional USGA agronomist to learn more about data collection and how it can improve your management programs.
Central Region Agronomists:
Zach Nicoludis, regional director, Central Region – znicoludis@usga.org
Tom Gould, agronomist – tgould@usga.org
Information on the USGA’s Course Consulting Service
Contact the Green Section Staff