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Stimpmeter Instruction Booklet
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.
Known as the father of the Stimpmeter, Edward S. Stimpson, left,
was an accomplished golfer. (USGA Photo Archives)
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.
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.
The Stimpmeter is an extruded aluminum bar, 36 inches long, with
a V-shaped groove extending along its entire length. It has a precisely
milled ball-release notch 30" from the tapered end (the end that
rests on the ground). The underside of the tapered end is milled
away to reduce bounce as a rolling ball makes contact with the green.
Known as the father of the Stimpmeter,
Edward S. Stimpson, left, was an accomplished golfer. (USGA
Photo Archives)
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The V-shaped groove has an included angle of 145 degrees, thereby
supporting a golf ball at two points ½" apart. A ball rolling down
the groove has a slight overspin, which is thoroughly consistent
and has no deleterious effect on the ensuing measurments.
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.
Although the Stimpmeter is sturdily built, it is a precision instrument
and should be protected from damage. When not in use, it should
be stored in a plastic tube or case. Even relatively slight damage
to the release notch or to the groove may cause errors.
Equipment Required:
- Stimpmeter
- Three golf balls
- Three tees
- One 10- or 12-foot measuring tape
- One Data Sheet
Step 1 Select a level area on the green, approximately
10 feet by 10 feet. (A simple means of checking for al evel area
is to lay the stimpmeter on the green and place a ball in the V-shaped
groove - the movement of the ball will indicate whether or not the
area is reasonably level).
Step 2 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.
Step 3 All three balls should come to rest not
more than 8 inches apart. (Should they be farther apart than that,
the Stimpmeter may have moved too much during the series, the balls
may be damaged or of inferior quality, or unusual conditions may
exist. In any event, 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.
Step 4 Repeat Step 2, 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.)
Step 5 Repeat Step 3, thereby establishing the
length of the second series of rolls. Step
6 Measure the two distances - for the first series and
the second series - and calculate their average. Record this as
the speed of the green.
Note: Should the difference in length between the
first and second series be greater than 18 inches, the accuracy
of the resulting average may be questionable. The area selected
for the test may not have been sufficiently level - or sufficiently
representative of the green - in which case it is advisable to select
another area and repeat the test. Sometimes a green may be so severely
undulating or sloping that a level area is simply not available
(which the data record should indicate).
- Selecting a reasonably level test area is important. Measurements
taken up or down a slope, over mounds, etc., will result in
misleading data.
- Conditions during a test are important. Initially , test your
greens under optimum conditions - a cleanly mowed, dry, smooth
surface on a calm day. Once this basic speed has been established,
you can then document speeds as they vary under unusual conditions:
windy days, wet surfaces, non-mowed, recently topdressed , time
of day, before and after fertilizer applications, etc. The data
thus accumulated will lead to a better understanding of how
different management practices affect the speed and consistency
of each green on your golf course.
- Practice makes perfect. A relatively small amount of practice
in using the Stimpmeter will increase the accuracy and consistency
of your data.
- Keep thorough records. Obviously, complete and accurate record,
maintained over extended periods, are the most useful.
Once the Stimpmeter is put into use at your course and the resulting
information is analyzed and acted upon, the possibilities for improved
playing conditions are virtually endless. Green speeds for individual
golf courses should remain up to the course officials, with the
input of the superintendent, of each facility.
Stimpmeter Readings on American golf courses generally range from
7 feet to 12 feet, depending on many factors (e.g. Slope, Contours,
Green Size, Grasses, Weather, Budgets etc.). Experience shows that
trying to keep the speed above 10 feet on a consistent basis usually
causes difficult-to-manage turf problems and is not recommended.
The manner in which putting greens are managed has a tremendous
influence on their speed and consistency. Most of these factors
are known to some degree, but almost all are worthy of research.
Following are some of the major variables that using the Stimpmeter
will help us to understand more effectively:
- Mowing height and frequency of cut are extremely
important considerations. The mower's bench setting is no guarantee
that greens are cut at a prescribed height. More over the condition
of the mowers; the type of mowers (floating or rigid cutting
units); attachments such as Wiehle rollers, groomers, brushes,
and combs; all can make a difference in the cut and green speed.
So does double-cutting, verticutting and rolling. The precise
effect of each of these factors can be measured with the Stimpmeter.
- Watering practices and surface moisture (dew)
are crucial to green speeds. Moist turf will be slower than
dry turf at any mowing height.
- Fertilizing practices can be studied, such
as the effects of rate and frequency of application, nitrogen
source, and nutrient balance.
- Grain is sometimes a deterrent to uniformity
of speed. How grain is affected by changes in direction of cut,
use of vertical mowing equipment, riding versus single unit
mowers, etc., can be studied a they relate to green speed.
- The effects of aeration, spiking, and topdressing can be measured,
both before and after treatments.
- Speed variations among the different grasses presently used
for putting greens can be documented.
- By keeping good records, you will be better able to observe,
determine, and explain variances in green speed throughout the
year and compensate for them. For example, in spring, when Poa
annua produces excessive seedheads, greens can be slower and
more bumpy. Your records will serve as a reminder to topdress,
begin vertical mowing, or schedule other practices calculated
to help maintain the desired speed and consistency.
Knowing the speed of the greens may assist in determining whether
a hole location is fair or unfair. A green so fast (or a hole cut
in such a position) that a ball cannot be stopped near the hole
from any point on the green, for example, is an unfair challenge.
Championship greens should be fast and uniformly paced, firm but
resilient. They should place a premium on well-executed shots, while
exacting a penalty for less precise shots.
Close daily mowing, a light nutrient program, proper irrigation
scheduling, a good topdressing schedule, and a minimum of thatch
are the accepted means of achieving excellent greens. The test for
determining whether a surface is properly firm but resilient is
the type of ball mark that results from a distance shot onto the
green. If the turf within the ball-mark depression holds together,
the green has the firmness required of a championship green.
Strive for championship conditions only for limited periods of time,
principally for important club events. Turfgrass failure is common
when championship conditions are maintained for too long or when
adverse weather conditions occur.
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