Published in Crop Sci. 44:214-217 (2004).
© 2004 Crop Science Society of America
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TURFGRASS SCIENCE
Measuring Ball Lie on Golf Course Fairways
L. Cellaa,
T. B. Voigt*,b and
T. W. Fermanianb
a Tamarack Golf Club, 24032 Royal Worthington Dr., Naperville, IL 60564
b Dep. of Natural Resources and Environmental Sci., Univ. of Illinois, 1102 South Goodwin Ave., Urbana, IL 61801
* Corresponding author (tvoigt{at}uiuc.edu).
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ABSTRACT
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Ball lie on a golf course fairway can impact a golfer's ability to control a shot. At present, there is no quantitative method to accurately measure golf ball lie (the amount of the ball exposed above the turfgrass canopy) on short-cut fairway turf. The objective of this work was to develop an instrument capable of accurately and quantitatively measuring golf ball lie on short-cut (1.27 cm) fairway turf. In previous work, a device (Lie-N-Eye) that measured golf ball lie on high-cut fairway turf (1.6–2.5 cm) was developed and tested on 25 Kentucky bluegrass (Poa pratensis L.) cultivars. That device lacked the sensitivity required to make measurements on short-cut turf. An improved device (Lie-N-Eye II) was developed to measure golf ball lie on short-cut (1.27 cm) bentgrass (Agrostis spp.) fairway turfgrasses. In October 2000, Lie-N-Eye II was tested on three creeping bentgrass [Agrostis stolonifera var. palustris (Huds.) Farw.] and three colonial bentgrass (A. capillaris L.) cultivars and adequately measured ball lie differences among bentgrass cultivars and species. Ball lies ranged from 38.7 mm to 40.7 mm of the ball exposed above the canopy (90.7 to 95.4% of the golf ball). Power curves generated from 18 measurements on each of six bentgrass cultivars indicate Lie-N-Eye II was able to detect a 1.65-mm difference between ball lies with a probability of approximately 90%.
Abbreviations: SPC, statistical process control
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INTRODUCTION
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AFTER LANDING on fairway turf, a golf ball must be played as it lies (Anonymous, 2002); a golfer cannot touch or improve the lie of the ball and must play it as it is found in these two areas. Thus, acceptable and consistent lies in which much of the golf ball is supported above the turf canopy are desirable characteristics of a golf course fairway, as well as rewards for well-struck shots.
The position of a golf ball on a fairway is determined by many factors. Beard (2002) states that turf species and cultivar selection are the main factors that determine ball lie. Furthermore, good fairway playability is associated with turf species and cultivars that are dense, uniform, smooth, firm, and resilient (Beard, 2002).
Equipment has been developed to quantify issues related to turf playability including the Stimpmeter (Thomas, 1983), a modified Stimpmeter (Gaussoin et al., 1995), and a device that measures golf ball deceleration on putting greens (Rist et al., 1999). In other work, Shearman and Beard (1975) used an apparatus to measure load-bearing capacity in laboratory experiments and found turfgrass species differ in their ability to support weight. They also found a positive correlation between this factor and the plant's cell wall components. In field studies, Erusha et al. (1999) found significant differences among turfgrass species' ability to support weight by identifying the resistance of the turfgrass plant to a uniform downward force. These differences were attributed to plant density and stiffness.
Cella (2001) developed the Lie-N-Eye, a device designed to measure the ability of a turfgrass to support the weight of a golf ball and determine its lie within cut fairway turfgrasses by measuring the amount of golf ball exposed above the turf canopy. The Lie-N-Eye was able to detect ball lie differences among 25 Kentucky bluegrass cultivars mowed at 1.6 to 2.5 cm and managed under golf course fairway conditions (Cella, 2001). The main body of Lie-N-Eye is a Mitutoyo Digimatic Caliper (MTI Corporation, Aurora, IL) with two plates installed to extend the caliper measuring faces and a handle.
While the Lie-N-Eye was able to determine ball lie in high-cut turf, it lacked the sensitivity to measure golf ball lie differences in short-cut turf (1.27 cm). Determining ball lie differences in short-cut turf might prove useful for research that evaluates turf cultivars and be relevant with the trend toward short-cut fairways. An improved device, Lie-N-Eye II, was developed to identify ball lie in short-cut fairway turfs. The objective of this work is to evaluate the ability and accuracy of Lie-N-Eye II when measuring golf ball lie on short-cut fairway-height turfgrasses.
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MATERIALS AND METHODS
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Lie-N-Eye II (Fig. 1) operates similarly to Lie-N-Eye as it measures the distance between the turf canopy and the top of the golf ball (Fig. 2). The main body of Lie-N-Eye II is a Mitutoyo Digimatic Absolute Caliper (MTI Corp., Aurora, IL) Model 500-170 with a statistical process control (SPC) output (Table 1). Features of Lie-N-Eye II include upper and lower plates of extruded aluminum and Acrylite FF, respectively, that measure the ball perpendicular to the caliper. An aluminum handle was installed on the rear of the device and fastened to the Acrylite FF. Lie-N-Eye II was connected to a Palm IIIx connected organizer. Data was transferred from the device via Mitutoyo SPC connecting cable No. 959150 (2 m) and stored via DataGet software.
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Fig. 1. Lie-N-Eye II: (A) Upper stainless steel measuring plate; (B) Acrylite lower plate; (C) aluminum handle; and (D) Mitutoyo Digimatic Absolute Caliper.
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Plots 3.05 x 1.52 m of three cultivars each of creeping bentgrass and colonial bentgrass (Table 2) were planted in September 1998 at the Landscape Horticulture Research Center, Urbana, IL, in a randomized complete block design with three replications. The soil type was a Catlin silt loam (fine-silty, mixed, superactive, mesic Oxyaquic Argiudolls). The bentgrasses were maintained at 1.27 cm, received 195 kg N ha–1, and were irrigated as needed to maintain acceptable golf course fairway quality. Six ball lie measurements per plot were made with Lie-N-Eye II on 18 Oct. 2000 (Fig. 2). Plots were mowed before ball-lie measurement. A modified Stimpmeter, similar to one used by Gaussoin et al. (1995), was used to uniformly roll each ball in all plots.
Means of 18 measurements (six measurements per plot with three replications) were separated by Fisher's Protected LSD (Steel and Torrie, 1980) at the 5% probability level. Power curves for detecting differences between measurements were obtained with the standard t test obtained by Monte Carlo variance (Cohen, 1988) within replications estimated from the measured ball lies.
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RESULTS AND DISCUSSION
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The Lie-N-Eye II proved to be effective in measuring significant differences in ball lie means on short-cut fairway turfgrasses. The creeping bentgrass cultivar L-93 (Table 2) had the highest ball lie mean value of the six grasses tested, while ‘Tiger’ colonial bentgrass had the lowest. Among creeping bentgrasses, the newer, denser cultivar L-93 had significantly higher ball lie than ‘Penncross’, a less dense, older cultivar. There was no significant ball-lie difference among the colonial bentgrasses. Tiger colonial bentgrass had the lowest standard deviation of all six bentgrasses, indicating it provided the most consistent ball lie within and among plots. All six grasses supported the ball well with at least 90% of the ball exposed for striking. A golf ball's diameter cannot be <42.67 mm (Anonymous, 2002), and ball lie means ranged from 38.7 mm to 40.7 mm. Thus, depending on cultivar, 90.7% to 95.4% of the ball was exposed above the turf canopy (Table 2).
Power curves were developed for detecting differences in ball-lie accuracy for 6, 18, and 36 measurements per species (Fig. 3). The two-sample t test of ball lie is used to detect the difference among cultivars. The power curve derived by using Lie-N-Eye II to make 18 measurements per cultivar (six measurements per cultivar with three replications) on two species of bentgrass indicates that the equipment is capable of identifying a 1.65-mm difference between ball lies with approximately 90% confidence. As differences in ball lie increase, the chance of identifying the difference also increases. The power curves are based on an overall variance of 2.35 mm (5.5% of a golf ball diameter).
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Fig. 3. Power curves for detecting differences in ball lie accuracy (n = the number of measurements per cultivar).
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Additional power curves were developed to determine the accuracy when making six and 36 ball lie measurements (Fig. 3) per fairway or cultivar. Making six measurements per fairway, a superintendent can detect a 2-mm difference between fairways with a probability of 53%. Increasing the number of ball lie measurements to 36 per fairway increases the power so that the t test can detect a difference of 1.2 mm with a probability >90%.
On the basis of these results, Lie-N-Eye II was able to adequately differentiate ball lie produced by both species of short-cut bentgrass. The device proved to be accurate and easy to operate with minimal training required. Data transfer to a handheld (PDA) storage device improved data organization and reduced data-collection times was also relatively simple. With practice and when connected to a PDA, the entire process of rolling the golf ball, measuring its position, and entering the measurement takes less than 30 s. A turf manager wishing to determine fairway uniformity on a golf course should be willing to make six measurements per fairway across 18 fairways. Moreover, a researcher evaluating short-cut fairway grasses might be interested in improving the accuracy of 18 measurements by making 36 (or more) measurements.
While this device is able to accurately identify the ability of a turfgrass species or cultivar to support a golf ball, future work remains to determine the causes of the differences. As previously mentioned (Shearman and Beard, 1975), the differences may relate to morphological differences such as leaf angle, leaf width and density, or to differences in cell-wall makeup or ability to maintain turgor under a wide range of management or environmental conditions.
Future uses of this device may include testing the impacts of cultural practices such as mowing height, nutrition, and growth regulation on ball lie on fairway turfgrasses. In addition, measurements conducted on golf courses may identify ball position variability on individual fairways and among all of a golf course's fairways.
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ACKNOWLEDGMENTS
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The authors thank Drs. Darin Lickfeldt, Clark Throssell, and Xuming He for generously assisting with data collection and analyses. The authors also thank the Illinois Turfgrass Foundation and the Agricultural Experiment Station at the College of Agricultural, Consumer, and Environmental Sciences, University of Illinois Urbana-Champaign for financially supporting this work.
Received for publication February 6, 2003.
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REFERENCES
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- Anonymous. 2002. The rules of golf and the rules of amateur status 2002–03. United States Golf Association, Far Hills, NJ.
- Beard, J.B. 2002. Turf management for golf courses. 2nd ed. Ann Arbor Press, Chelsea, MI.
- Cella, L. 2001. Measuring ball lie on golf course fairways. M.S. thesis. Univ. Illinois, Urbana-Champaign.
- Cohen, J. 1988. Statistical power analysis for the behavioral sciences. Lawrence Erlbaum Assoc., NJ.
- Erusha, K.S., R.C. Shearman, and L.A. Wit. 1999. A device to measure turfgrass load bearing capacity under field conditions. Crop Sci. 39:1516–1517.[Abstract/Free Full Text]
- Gaussoin, R., J. Nus, and L. Leuthold. 1995. A modified Stimpmeter for small-plot turfgrass research. HortScience 30(3):547–548.
- Rist, A.M., M.F. Kocher, W.W. Stroup, R.E. Gaussoin, R.D. Grisso, and R.C. Shearman. 1999. Golf ball deceleration measuring system to evaluate surface uniformity on golf course greens. Crop Sci. 39(3):741–745.
- Shearman, R.C., and J.B. Beard. 1975. Turfgrass wear tolerance mechanisms: III. Physiological, morphological and anatomical characteristics associated with turfgrass wear tolerance. Agron. J. 67:215–218.[Abstract/Free Full Text]
- Steel, R.D.G., and J.H. Torrie. 1980. Principles and procedures of statistics: A biometrical approach. 2nd ed. McGraw-Hill, New York.
- Thomas, F.W. 1983. Ups and downs with the stimpmeter: How it all began. USGA Green Sect. Rec. 21(2):10–11.
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ABSTRACT
INTRODUCTION
