A Korea Professional Golfers’ Association (KPGA) Tour rules official measures green firmness using a turf firmness meter. Seoul Economic Daily DB
“Average green speed of 11 feet [about 3.35 meters], average green firmness of 0.373 inches [about 9.47 millimeters].”
Those figures came from the daily course-setup data distributed during last month’s Open Championship, men’s golf’s major tournament, by the R&A, which runs the event. The 154th Open, won by Ryan Fox of New Zealand, was played at Royal Birkdale Golf Club in England.
Measuring green speed with a Stimpmeter. Seoul Economic Daily DB
The phrase “green firmness” catches the eye. Green speed is a concept even weekend golfers know well. Green firmness likely refers to how hard the surface is, but seeing it expressed as a number may be unfamiliar. The length of the fairway, rough and green grass, the fairway width, the green speed and the pin positions are all announced day by day during a tournament. But data on green firmness is rarely released to the media, not only in Korea but also on the U.S. PGA Tour.
Green speed is measured with a Stimpmeter, an aluminum bar-shaped tool 36 inches (about 91.4 centimeters) long with a V-shaped rail. A golf ball is rolled down the rail while the tool is tilted at 22 degrees to the ground, and the distance the ball travels is recorded in feet or meters. The figure is expressed as an average of readings taken at several points on each green. Green speed has a major effect on the sense of distance and the amount of break in putting.
Green firmness is a numerical measure of how hard or soft a green’s surface is. Major golf governing bodies mainly use a tool called the Turf Firmness Meter to take the measurement.
At first glance the Turf Firmness Meter resembles a bicycle tire pump and is about the same size. It consists of a cylindrical body and a handle at the top, and the handle is connected to a round-tipped metal hammer inside the cylinder. With the meter standing on the green surface, you grip the handle, pull it all the way up and let go, and the impact of the falling metal hammer creates a dent pressed into the green. The maximum depth of this dent is measured in inches or millimeters, with a digital depth-measuring device providing the reading. Because it measures the deformation of the putting green surface, a higher number means a softer green.
Green firmness began in the realm of course management. Firm, fast greens are ideal for both greenkeepers and players. They tend to suffer less damage from ball marks (pitch marks) left when a ball lands, from the pressure grass takes when walked on, and from wind and rain, giving them an advantage in upkeep. In modern golf, players seek approach shots that land on the green, bounce once or twice and stop, rather than greens so soft that excessive backspin is applied. Course managers explain that the point of measuring firmness is not to obtain a number for hardness in itself, but that it can be a useful tool for assessing how various management methods affect firmness.
In truth, what concerns us golfers is not course management but score management. Paying even a little attention to green firmness can raise the level of your approach play. For example, if a green is firm, a higher-trajectory iron shot is better for stopping the ball, and rather than aiming directly at the pin, it will be advantageous to land the ball short of the pin. On a soft green, by contrast, you should factor in that there will not be much run after landing. Of course, most courses announce green speed, but places that tell you the green firmness are hard to find. It is difficult to confirm with a number, but if you gauge the green firmness along with the green speed even roughly as high, medium or low over the first hole or two, and keep it in mind as you play, you may discover another pleasure in attacking a course.
One more note: the Stimpmeter and the firmness meter are spelled differently because the Stimpmeter, which measures green speed, is a compound word named after Edward S. Stimpson, the amateur golfer who invented it in 1935.
They say that golf’s almost only drawback is that it is so much fun it is easy to get addicted. I hope we can share the joy of “reading golf,” which is something different again from playing golf and watching golf.