Professional Golfers Conclude that Spike Design Affects Putting Green Quality

Thomas A. Nikolai, 154B Plant and Soil Science Building, Department of Crop and Soil Science, Michigan State University, East Lansing 43210; Douglas E. Karcher, 316 Plant Sciences Building, Department of Horticulture, University of Arkansas, Fayetteville 72701; and John C. Sorochan, 252 Plant Sciences Building, Department of Plant Science, University of Tennessee, Knoxville 37996

Corresponding author: Douglas E. Karcher. karcher@uark.edu

The banning of metal spikes on golf shoes began as a winter rule to protect dormant golf greens in the Pacific Northwest USA in the early 1990s (1). Within a decade this seasonal rule resulted in a near worldwide ban of metal spikes from golf course greens. However, it would be negligent to assume that all alternative spikes introduced to the golf industry are as green-friendly as the earliest models (2). Although previous research has shown that different types of spikes vary significantly with regard to putting green turf damage following foot traffic (3), putting green quality has not been evaluated by professional golfers in such a study. The objective of the following research was to determine how putting green quality is affected by various spikes, as determined by professional golfers.

Shoe Spike Traffic and Golfer Ratings

This study was conducted on 31 July and 1 August 2006 on a 1-year-old nursery green at Warwick Hills Country Club (Grand Blanc, MI). The green was a mixed species stand of creeping bentgrass (Agrostis stolonifera L.) and annual bluegrass (Poa annua L.) established on a 25-cm sand cap overlying a native sandy loam soil. The nursery green was maintained similar to the other greens at this championship golf course (3.2-mm mowing height).

Golfer traffic was simulated using eight different shoe spikes (Fig. 1) across 24 circular plots (3 replications, each plot 90 cm diameter) on the green during the afternoon of 31 July and again the following morning. On 31 July, 200 rounds of golf were simulated within each plot by repeatedly bending down and motioning to pick up a golf ball in the center of the plot. An additional 100 rounds were simulated on 1 August. The same model golf shoe was used for each spike treatment. Three non-trafficked control plots were also included in the study.

On 1 August 2006, during a practice round of the 2006 PGA Buick Open, professional golfers were asked to visually rate the plots for putting green quality on a 1 to 5 scale (1 = excellent, 2 = very good, 3 = good, 4 = fair, and 5 = poor), resulting in 30 sets of ratings.

Rating data were analyzed using logistic regression (a proportional odds model) to compute prediction probabilities for each spike treatment and rating category combination (Fig. 1). Model parameters for each treatment, with confidence intervals, were estimated through maximum likelihood calculations, which were used to separate treatments through PROC LOGISTIC contrast statements (α = 0.05) (SAS Institute Inc., Cary, NC).

Professional Golfer Survey Results

Probability distributions for each spike treatment are shown in Fig. 1. The non-trafficked control was rated significantly better than all of the spike treatments. Spike 1 was rated higher than all other spike treatments with an 86% probability that putting green quality would be rated good or higher following intense traffic. Spike 2, 3, 4, and 5 were rated similarly, except that Spike 2 (63% good or higher) was rated significantly better than Spike 5 (51% good or higher). Spike 6, 7, and 8 were rated the lowest, with probabilities that putting green quality would be rated less than good 76%, 81%, and 83%, of the time, respectively.

These results indicate that spikes which are designed for aggressive traction such as Spike 6, 7, and 8 (more rigid material and protrusions extending further from the sole) tend to reduce putting green quality following foot traffic. Specifically, Spike 5 is similar to Spike 7 except that the central metal spike has been removed (Fig. 1), which significantly improved putting green quality for Spike 5.

In conclusion, golf course managers and tournament officials should be aware that putting green quality is affected significantly by the golf spike in use. However, it is important to note that other factors should be considered when selecting golf spikes, including traction, comfort, and infrastructure damage.

Fig. 1. Effect of spike treatment on putting green quality as determined by professional golfers. Probabilities of spikes being rated into individual categories are labeled within bars. Shoe spikes not sharing a letter were rated significantly different (P = 0.05).

Literature Cited

1. Gilhuly, L. 1996. The metallic mashers of monocots: Golf spikes! USGA Green Section Record 34:1-4.

2. Nikolai, T. A., Rogers, J. N. III, Karcher, D., Hardy, J., and Rieke, P. E. 2000. Grass vs. concrete: Golf shoe traction: Where you stand on alternative spikes may depend on where you walk. Golf Course Manage. 68:49-54.

3. Rogers, J. N. III, Karcher, D. E., Nikolai, T. A., Hardy, J. A., and Rieke, P. E. 1999. Greens, cleats interact in traveling study. Golf Course Manage. 67:61-65.