Cant, Olivia (2020) Exploring the effects of ball speed and spin in Grand Slam tennis match-play. PhD thesis, Victoria University.

Abstract

This thesis featured modern technology to investigate the effect of ball speed and spin on aspects of on-court hitting performance. Adjusting a shot’s ball flight – be that in the form of speed and/or spin – is a tennis tactic that features in almost every point that is played. Past research has highlighted the importance of generating high shot speeds for on-court performance, while the limited empirical work that has examined the influence of ball spin has largely relied on indirect measures. Indeed, even with ball-tracking systems such as Hawk-Eye being commonplace at professional-level tournaments, the precision of proprietary spin measures is not well understood and limits the extent to which they can be used to derive insight by scientists and practitioners. During rally play, it is rare for players to produce just ball speed or spin for any given shot; more logically generating varying combinations of both speed and spin. The interplay between these characteristics has been largely overlooked in the literature; so much so that the popular concept of stroke heaviness, thought to capture the unique combined effects of speed and spin, has not been explored. Further, research relating shot characteristics (i.e., speed) with point outcomes is too simplistic as it essentially disregards the influence of one shot on the next, including how incoming shot characteristics shape the impact and quality of an opponent’s reply. To address these gaps in the literature, this thesis validated methods to estimate ball spin from the sport’s most common multi-camera tracking technology (Hawk-Eye), finding that a theoretical ball trajectory model applied to Hawk-Eye outputs was most accurate. This method estimated spin rate with a root mean square error (RMSE) of 221.93 RPM and correctly classified the spin direction of all trials, thus, outperforming Hawk-Eye’s proprietary spin rate (RMSE: 549.56 RPM) and direction (97.60% correctly classified) measure. This has widespread applications given the extent to which Hawk- Eye is used during professional matches and allowed the thesis’s subsequent studies to probe spatiotemporal data from Grand Slam matches. This involved the novel exploration of player and data-driven views of the attributes and effects of stroke heaviness and then investigation of the effect of incoming shot characteristics (i.e., speed, spin, landing depth) on aspects of on-court hitting performance (i.e., player impact, return stroke quality). Investigating the concept of stroke heaviness highlighted the complexity of this style of shot-making, while further examination of the influence of incoming shot speed and spin on player impact and ball-striking revealed that producing a consistent contact point and return stroke was outside of a player’s full control. To summarise, developing a method to accurately estimate ball spin from ball- tracking data allowed this thesis to extend current knowledge on the influence of incoming shot characteristics on aspects of performance during Grand Slam matches. Accordingly this thesis provides coaches and players with a method to estimate spin in practice and match contexts and highlights how shot characteristics can be varied to influence an opponent’s contact point and the quality of their next shot.

Search Google Scholar

Repository staff login