QA Stimpmeter Simplified


Editor's Note: This is the latest in a weekly Q&A feature from The Golf Channel's Chief Technical Advisor Frank Thomas. To submit a question for possible use in this column, email
Hi Mr Thomas,
I believe you had something to do with green speed measurement standards. Can you tell me how the green speed is measured what were the green speeds at the U.S. Open at Winged Foot? - George M.

Yes I did have something to do with the Stimpmeter and you can read about it on under Frankly Speaking The Birth of the Stimpmeter. The concept design was to develop a quantitative measure of the speed of greens. Prior to the adoption of this device as an official measure of green speeds it was left to somebodys memory and personal experience about how fast greens should be.

Briefly the device consists of a grooved stick with a notch in it to hold a golf ball. When raised at one end closest to the notch with the other end resting on the surface of the green at a certain point (20 degrees tilt) the ball will release and roll down the groove. It will contact the green with the same kinetic energy every time relying on gravity and the slope of the stick (Stimpmeter). When it reaches the surface of a flat spot on the green it will roll for some distance depending on the speed of the green. This measurement -- in feet -- is measured and reported as the speed of the green.
The speed can be controlled by rolling and also the height of the cut when the green is mowed.
The greens at the U.S. Open this year were right at 12 feet, which is about as fast as they could have been given the undulations of the greens.
The Stimpmeter reading is now the International Standard for measuring green speeds, and I am very proud of this.
Hi Frank,
If I carry less than fourteen clubs, is it legal to change the weights in my driver during a round. - JC, Denver

The answer is NO as you are not allowed to adjust a club during a round. The fact that most of the latest adjustable drivers have four weight ports, the number of different adjustments you can make will be greater than the number of clubs you have in your bag. So even if you were to use the 13 clubs as an excuse to adjust your club you would violate the fourteen club rule.
The rule requires that if a club is designed to be adjustable the adjustment be made with a special tool not normally carried by a golfer, such as a spike wrench or a ball mark repair tool. This is to take temptation away from the golfer making an adjustment during a round.

JC good try but NO.

Do golf balls have a shelf life? Will playing with ball one or two years old, but never hit reduce it performance or distance? -- Thank You, Jack in N.C.

Golf balls do not have a shelf life that you need to worry about.
I say this because balls will deteriorate slower than technology is advancing and even though technology is still moving along very slowly by the time your balls are affected by age (about 15 to 20 years) you may want to look at something with newer technology. The advances that will be made will not be in distance but rather in durability and control and even customizing for specific swing speeds.
This was not the case when we used wound balls but those days are long gone. If you are talking abut wound balls then the modern multi-layered balls have already done you in. Even though the wound balls will deteriorate slower than the new balls the technology has already made these balls obsolete.
With all the hybrids being used these days, why don't major manufactures and component suppliers alike stop offering 3-pw sets and start offering 5-GW sets with the option of hybrids or 3/4 iron, just like a SW or LW that they do now. - Tom Matthews

The main reason is that they have not truly come to terms with the change in set make up and also that they can sell more clubs. A full set, as we knew it -- 2-PW& SW, is now obsolete. If you have to buy this set you need to dump at least three clubs (2- 3- & 4- irons) and replace these with two hybrids and a Gap wedge. Then if you decide you need some more control around the greens with a Lob wedge you may have to dump your 5-wood.
Things will soon change as the set make up will adjust to the trends and those manufacturers who do not shift will not get the business.

Frank Thomas, inventor of the graphite shaft, is founder of Frankly Golf, a company dedicated to Helping Golfers. Frank is Chief Technical Advisor to The Golf Channel and Golf Digest. He served as Technical Director of the USGA for 26 years and directed the development of the GHIN System and introduced the Stimpmeter to the world of golf. To email a question for possible use in an upcoming Let's Be Frank column, please email