This calculator requires the use of Javascript enabled and capable browsers. This golf calculator is designed to be an emulation of the general ideas of the Stimpmeter, used by the USGA and golf course greenskeepers everywhere in the US to determine the speed of the greens for putting, and to provide general thoughts for a better Stimpmeter design and use process. This is actually two calculators; the upper doing the math calculations for the length of the two undetermined sides and the undetermined angle of the simulated Stimpmeter, visualized as a triangle. To use this calculator, verify that side c has a value in it and angles A and C have values in them; the default values present should be correct for our design. Then click on Calculate. The default and calculated values are the ones described later on this page.
The lower calculator does the math for the Stimpmeter rating, using the 4 direction process described in this text. Enter the number of inches or centimeters that the ball rolls on the green from the Stimpmeter in all 12 fields for all 12 validating actions. Data input can be in either inches or centimeters. Then click on Calculate Rating. The results returned for each of the 4 directions are the deviation in "Good", "Bad" or "Invalid"; Good is within the acceptable USGA limits, Bad is for bad data and Invalid is outside of the USGA limits. Also given is the average in of 3 balls in that direction in BOTH inches and centimeters. The deviation and average in inches and centimeters is also given for the total of the 4 directions. Finally, if all data is within the very broad USGA limits, the rating is given for the single green under test. For the data to be within USGA limits as a valid measurement, all 3 balls in any given direction must come to rest within 8 inches of each other in length (as defined by the USGA instruction manual for the Stimpmeter) from the departure point of the Stimpmeter. (Our opinion is that 8 inches is too wide to be a valid test. We suggest 4, 3 or 2 inches using our design modification.)
The USGA Stimpmeter is a measuring device used to determine the speed of putting greens on golf courses by applying a given and repeatable force to a golf ball and measuring the distance traveled in feet. It was designed by a golfer, an amateur but very good player, Edward Stimpson, Sr. in 1935, adopted and adapted by the USGA in 1976, and made available to the nation's courses in 1978. For the most part, it has gone unchanged since then. (Here is the USGA instruction information for a Stimpmeter.) The original purpose of it was to provide some sort of standardization to the detection of the speed and distance of a golf ball rolling on a putting green. While we at CSGNetwork.com agree with the philosophy of the concept and the general use of such a device, we do feel the current USGA official Stimpmeter is inherently flawed in design for standardization; any and every mechanical engineer that analyzes the device and process will agree with us. We also feel that since there is no real credible standard in the use of the device, that the resulting data is consistently and inherently flawed. In other words, since the USGA official device is NOT sold to the public and only to member golf courses and country clubs, those organizations use them as they wish, more or less without supervision, easily distorting the data by accident or otherwise. We also acknowledge that fact that all players "have an opinion" as to what the ideal speed of greens should be all the time. That speed and that opinion may be credible to some; however, greens superintendents and greenskeepers are (at least they SHOULD be) the final authority for the conditions available and for the conditions during the year and for the particular grass on that course. Obviously, all greens and the speeds thereof are not the same all of the time, even on the same course, much less all over the country on EVERY course. That being stated, we feel that portraying that any green is a particular speed on the Stimpmeter has enough built-in variables by nature, without adding additional ones through the design flaws of the measuring device and the methodology of a human measuring without a standard set of rules or guidelines. We feel we have improved the device design so that it cuts out the variable factors in the device and have come up with one plan to cut out the potential errors in the methodology, thus creating reasonably credible data worldwide including metric measurements. We don't want to profit from either and would be happy to provide it to the USGA, as is, to improve the game. As a former golf professional, I recognize that the game of golf does MUCH in both character and enjoyment, for the people that play it correctly; the key word there is CORRECTLY. The word correctly does not mean to play at a high level of ability; it means to enjoy the game as intended and play within the scope of the rules. Those that have benefited SHOULD give back to the game to enhance it for the next generation. Our idea of redesign and this improvement proposal (below) together, do just that.
The data of the generic triangle-like graphic (representing the new design of the Stimpmeter) is that side b sits on the ground, side a is perpendicular to the ground and side c joins them (such as the hypotenuse of a right triangle) and is the "trough" that a golf ball will roll down and onto the ground. (The idea of the trough is also a point of contention for us and will be discussed later.) Angle A is FIXED at 20 degrees, angle B is FIXED at 70 degrees and, angle C is a right angle, obviously 90 degrees. (The term FIXED in this case is meant to mean sturdily secured in the form of a triangle device with a non-changeable angle structure.) This structure is light weight but stable with no movement involved except for a trigger device at point gb, to release the ball. Side c is 36 inches long while the other sides are calculated (angle B is also calculated). Point gb on side c is where the golf ball starts the roll down the trough to the green; it is exactly 30 inches up side c. It has a mechanical "trigger" to hold the ball until manually released by the trigger. The velocity at the point the ball meets the green from coming down the trough (slope c), is about 6 ft/sec; that velocity is not an important figure but the fact that it is consistent is. Factors that could have an effect on that are the device base (side b) being level (N, S, E and W), altitude, atmospheric pressure, gravity, wind, moisture, and the weight and size of the ball. These measurements are correct and coincide with the general published information of the current Stimpmeter, if you wish to use them to build one on your own as an experiment.
The CURRENT trough (slope c) is made from angle aluminum so that the ball touches both sides about .5 inches apart; if the angle aluminum piece "V section" angle is exactly 145 degrees (according to the USGA), the USGA approved golf ball contacts the aluminum constantly at two points exactly .5 inches apart. The V portion of the device as it meets the ground is tapered so that there is no bounce of the golf ball as it impacts the ground. That tapering CANNOT change the angle with the ground from 20 degrees. The rating is derived from how far the ball rolls on the green after departing the Stimpmeter. If it rolls 6 feet, the rating is 6; if it rolls 6 feet, 6 inches (1/2 foot), the rating is 6.5, and so on. The rating system in not overly technical but requires use of feet and inches. That leaves out the majority of the world since they do NOT use feet and inches. The rating range for the Stimpmeter is currently from 1.x (very slow) to 14.x (very fast); we have no issue with that or any other number range so long as ONLY one is used. While I have seen fast greens (or things termed as greens) that exceeded the USGA 14.x limitation (and putting on them was virtually impossible), I have never personally seen a tested green less the 3.2 on the slow side.
At present, the Stimpmeter is a moving device that is lifted at one end to allow the ball to roll from an indention in the device, initiated by gravity to overcome inertia. That action is designed to take place at the point where the stationary end of the device meets the ground at 20 degrees. Without even throwing in the speed at which the device is lifted, red flags are already waving spelling out inconsistency.
What we would like to see is a TUBE at least 1/3 larger in diameter than the golf ball, instead of the angled aluminum. The same type of tube used for sprinkler systems... PVC; 2.5 inch PVC works nicely! (As a matter of interest, most golfers are NOT aware of the specifications for USGA approved golf balls. There is no MINIMUM weight for a golf ball; the maximum weight is 1.620 ounces. There is no MAXIMUM size for a golf ball; the minimum size is 1.680 inches in diameter, which eliminates the British "Pee-Wee" size ball from competition.) As far as the Stimpmeter design, the purpose and length, the release point and the angles can remain the same but the device should be STATIONARY as a standard. A single pivot "trigger" would manually be used to release the ball from the 30" inch mark; golf balls would be inserted at the 36" end (high end) of the device. In reality, this type of device, if level, reduces friction drag by 50% since the ball only contacts the interior surface of the tube at ONE point at any given time. Keep in mind that the purpose of the optimization is NOT for "high performance" as could possibly be assumed by this explanation, but is ONLY for reducing the number of variable factors in an effort to enhance consistent repetition. By the very design of ANY tube, it also would contact the ground at ONLY ONE point and inherently take away ground impact bounce of the ball as it departs from the inclined source. If level by the N, S, E and W method with side a being perpendicular with the surface of the ground in all directions. The measurements in real life CANNOT be done on level ground as is the desire now, except by accident. (That does not mean it SHOULD not be level; it just means that most greens are NOT level.) However, using the same N, S, E and W plan, if the device is used in four different directions, 3 balls in each direction, meeting the validation length guidelines and averaged, that takes gravity, wind, grain, break and virtually all other factors out of the equation. Each direction would have a "verifying deviation", for instance 2, 3 or 4 inches (as opposed to the current 8 inches) within its own 3 ball tests to qualify as valid. Say for instance, each ball rolled from the device in the same direction, could be no more than 8 inches difference in total length from the Stimpmeter, though the 8 inches is the USGA current value I am using for demonstration of an idea and not our suggested deviation distance. If the balls from each direction meet the verifying test, the measurement is validated for that direction. The same test would be done on a representative number of greens from the course, randomly chosen or selectively chosen as a hand picked representation. The reason for that being if all the greens are NOT more or less the same in conditions such a sunlight, shade, natural moisture content, additional moisture (watering procedures), subterrainial construction, surface resistance, surface wind blockage and type and direction of cutting, the factors are then NOT representative of the group. I also feel that such measurements should be tested for "time of day" consistency. Is all of this "overkill"? Perhaps, but compared to the amount of dollars in the industry, testing to other parts of the game such as balls and clubs, and the number of players worldwide involved with golf, this is just another stabilizing factor in an already wonderful game that allows very poor players, very good players, males and females, juniors and seniors, to compete more or less equally at any given time and course throughout the world.
The USGA Stimpmetered putting greens across the country to produce the following recommendations:
Low USGA limit: 1 foot
Slow greens: 4.5 feet
Medium greens: 6.5 feet
Fast greens: 8.5 feet
For the U.S. Open, they recommend:
Slow greens: 6.5 feet
Medium greens: 8.5 feet
Fast greens: 10.5 feet
High USGA limit: 15 feet
The greens at Oakmont Country Club are some of the fastest in the world, with readings of 13 to 15 feet.
Other sources for information on a Stimpmeter on the Internet are:
The Stimpmeter by the Rambling Man
Up with the Stimpmeter
Stimpmeter - Measure Putting Green Speed
Stimpmeter
Reading the greens
Tools of the Trade
Stimpmeter Definition
What Is A Stimpmeter?
The Birth of the Stimpmeter
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