Ever wondered how courses measure the speed of the greens, here is the history of the Stimpmeter and the instructions for how a course is supposed to accurately measure the speed of their greens:
One of the most significant aspects of a golf course is the uniformity of its greens. Variations in speed -- whether from one green to the next or on different parts of the same green -- can do more to negate a player's skill than can ragged fairways or unkempt bunkers. Most golf course superintendents are well aware of this problem, and constantly seek better ways to establish consistent speed on all their greens. The problem they face, however, is extremely complex. There are a host of variables that affect the speed with which a ball rolls on a putting surface.
Some 60 years ago, Edward S. Stimpson, the 1935 Massachusetts Amateur champion, addressed himself on this problem precisely: how to achieve accurate, objective, statistically valid measurements of the speed of a putting green.
The result of his efforts was the Stimpmeter. Mr. Stimpson's device was modified by the USGA's technical department in the mid-1970s and made available to golf course superintendents and course officials in 1978.
For the first time since its initial release, the USGA has updated the Stimpmeter. The new version allows for greater flexibility in measuring green speed, especially on undulating surfaces that have smaller areas of level turf, a necessity for measuring green speed.
Thirty-six inches long, the Stimpmeter features a lengthwise groove, with a notch about 30 inches from the tapered end. The ball sits in this notch at the starting position, lying flat on the ground; when the user lifts the other end of the Stimpmeter to an angle of about 22 degrees, gravity releases the ball from the notch.
The ball rolls down the Stimpmeter and along the green, and the average distance traveled by the ball after a number of attempts is the figure that has come to represent the speed of the green.
The Stimpmeter is a simple, accurate device manufactured by the USGA that allows one to make a standard measurement of -- and place a numerical figure on -- the speed of a putting green. It has proven to be an invaluable asset to the game of golf and a helpful management tool for the golf course superintendent, but it is not intended for course comparisons.
As green speeds have increased over the past three decades, users have come to need a flat portion of the green that is 10 to 15 feet long for an accurate reading with the original Stimpmeter. However, that length of level green surface is not available on all courses.
“As greens have gotten faster, it’s gotten harder to find that necessary length of level surface,” said Dave Oatis, director of the USGA Green Section’s Northeast Region.
To overcome this obstacle, the Green Section worked with Steve Quintavalla, Ph.D., of the USGA Research and Test Center. Quintavalla developed a two-sided Stimpmeter, which has an additional notch that rolls the ball half the distance of the original version. The new side works the same way, but users double the average roll distance to achieve the Stimpmeter reading.
The ball-release notch is designed so that a ball will always be released and start to roll when the Stimpmeter is raised to an angle of approximately 20 degrees. This feature ensures that the velocity of the ball will always be the same when it reaches the tapered end.
To obtain an accurate measurement of the speed of the greens, the following process is used:
Select a level area on the green, approximately 10 feet by 10 feet. Insert a tee in the green, near the edge of the area selected, to serve as a starting point. Holding the Stimpmeter by the notched end, rest the tapered end on the ground beside the tee, and aim it in the direction you intend to roll the ball. Put the ball in the notch and slowly raise the end until the ball starts to roll down the groove. Once the ball starts to roll, Hold the Stimpmeter steady until the ball reaches the putting surface. Repeat the same procedure with two more balls, keeping the tapered end on the same spot.
All three balls should come to rest not more than 8 inches apart. A pattern larger than 8 inches is of dubious accuracy, and the three-roll series should be repeated.
Assuming the balls stop within the prescribed 8- inch limit, insert a second tee in the green at their average stopping point. The distance between the two tees is the length of the first series of rolls.
The process is then repeated, using the second tee as a starting point and the first tee as an aiming point. In other words, roll a series of three balls along the same line, but in the opposite direction.
As before, repeat this step to verify the accuracy of the length of the second series of rolls. Measure the two distances - for the first series and the second series - and calculate their average. Record this as the speed of the green.
In terms of how the numbers represent "speed" of putts, the USGA has these recommendations. The greens at Oakmont Country Club (where the device was conceived) are some of the fastest in the world, with readings of 13–15 feet (4.0–4.6 m).
Course across the US:
Slow 4.5 feet (1.4 m)
Medium 6.5 feet (2.0 m)
Fast 8.5 feet (2.6 m)
For the U.S. Open, they recommend:
Slow 6.5 feet (2.0 m)
Medium 8.5 feet (2.6 m)
Fast 10.5 feet (3.2 m)
(From the pages of the USGA, I have pulled information on the history of the Stimpmeter. http://www.usga.org/course_care/articles/management/greens/Stimpmeter-In...)