Applied Research
Measuring the Accuracy and Precision of Ball-Roll Devices — Does Annual Bluegrass Influence Golf Ball Deceleration and Trajectory on Putting Greens? By Sandeep S. Rana, Doctorate Student, and Shawn D. Askew, Ph.D., Associate Professor and Extension Turfgrass Weed Specialist, Virginia Tech
A
nnual bluegrass (Poa annua) infestation on putting greens is often speculated to impact ball-roll distance and trajectory. Research at Virginia Tech showed that golf balls rolled almost a foot less when putting greens were infested with over 50% annual bluegrass compared to turf with less than 5% infestation. The ability to remove annual bluegrass from putting surfaces may increase interest in surface-smoothness
evaluation. Several devices are now being marketed to golf superintendents for evaluating putting-surface smoothness and ball-roll distance and trajectory, but few research studies have tested these devices for effects other than ball-roll distance. In addition, most studies suggest that statistical differences in ball-roll distance are usually attributed only to treatments that create large differences in the putting-surface uniformity.
Figure 1. Golf ball-roll distance as influenced by ball-roll device and ball type.
20 | Virginia Turfgrass Journal July/August 2015 www.vaturf.org
Our hypothesis is that the potential effects of annual bluegrass on ball-roll distance and trajectory will be too small to measure with commercially available devices. Therefore, research was conducted to measure the accuracy and precision of several ball-roll devices and golf balls that can be used in future field experiments to determine subtle differences in ball-roll deceleration and trajectory due to annual bluegrass infestation on putting greens.