The Biomechanics of Converting Torque into Spin Rate in Spin Bowlers Analyzed with a Smart Cricket Ball

BACKGROUND: In previous studies that analyzed the biomechanics of spin bowling with a smart cricket ball, it was evident that not all the torque applied to the ball was converted into spin rate, with varying losses among different bowlers. This study aims to investigate the factors contributing to these losses. METHODS: Developed in 2011, the world's first intelligent cricket ball features five physical and five skill performance parameters. Our study correlates five skill parameters with the ratio of total torque to spin rate to determine the most influential skill parameter. RESULTS: The parameter that most affected the conversion of torque to spin rate was the ratio of maximum angular acceleration to maximum angular velocity. Since the unit of the latter ratio is measured in s(–1) or Hz, we hypothesized that the duration of a time-window in which the torque is generated could be a factor in determining the effectiveness of torque to spin conversion. Upon closer examination of the data, we discovered that the spin torque (the torque component that boosts the spin rate) generated earlier in relation to the release point led to greater conversion of total torque into spin rate. Paradoxically, this occurred at smaller peak spin torques. As the time-window of the spin torque widens despite its decreasing magnitude, the angular impulse increases. CONCLUSIONS: As the skill parameter calculated from the ratio of maximum angular acceleration to maximum angular velocity correlates well with the time-window during which torque is generated, it can serve as a good indicator of skillful torque to spin conversion, and a potential parameter for talent identification.