Validation of ball spin estimates in tennis from multi-camera tracking data. Issue 3 (1st February 2020)

• Record Type: Journal Article
• Authors: Cant, Olivia; Kovalchik, Stephanie; Cross, Rod; Reid, Machar
• Is Part Of: Journal of sports sciences. Volume 38:Issue 3(2020)
• Page Start: 296
• Page End: 303
• Publication Date: 2020-02-01
• Subjects: Tennis -- hawk-eye -- ball spin; Sports -- Periodicals; Sports -- Physiological aspects -- Periodicals; Sports -- Psychological aspects -- Periodicals; 612.044
• DOI: 10.1080/02640414.2019.1697189
• Languages: English
• ISSNs: 0264-0414

Abstract

ABSTRACT: The purpose of this study was to examine the accuracy of methods to estimate ball spin rate and spin axis direction using multi-camera tracking technology. The method implemented by Hawk-Eye and a theoretical ball trajectory model were assessed for their accuracy against high speed-vision. A theoretical ball trajectory model was found to estimate ball spin rate and the spin axis direction more accurately than the method used by Hawk-Eye. The superior performance of the ball trajectory model was indicated by a lower mean bias and standard deviation (2.92 ± 222.76) than Hawk-Eye (−100.01 ± 542.44), as well as narrower limits of agreement and a 327.63 RPM lower RMSE. Spin rates less than 4500 RPM were estimated with the highest accuracy, but neither method was able to consistently and accurately estimate spin rates >4500 RPM. The application of a trajectory model to multi-camera ball tracking data provides a practical and non-invasive method to accurately estimate the spin imparted when hitting, allowing for large-scale collection of spin rates during matches.