Trackman 4: Within and between-session reliability and inter-relationships of launch monitor metrics during indoor testing in high-level golfers

The aims of the present study were to: 1) investigate the within and between-session reliability of the Trackman 4 launch monitor system, and 2) determine the inter-relationships of some of these commonly used metrics. Golfers attended two test sessions at an indoor golf academy and performed 10 shots using their own driver. Results showed excellent within and between-session reliability for CHS (ICC = 0.99; SEM = 1.64–1.67 mph), ball speed (ICC = 0.97–0.99; SEM = 2.46–4.42 mph) and carry distance (ICC = 0.91–0.97; SEM = 7.80–14.21 mph). In contrast, spin rate showed the worst reliability (ICC = 0.02–0.60; SEM = 240.93–454.62 º/s) and also exhibited significant differences between test sessions (g = –0.41; p < 0.05), as did smash factor (g = 0.47; p < 0.05) and dynamic loft (g = –0.21; p < 0.05). Near perfect associations were evident in both test sessions between CHS and ball speed (r = 0.98–0.99), CHS and carry distance (r = 0.94–0.95), ball speed and carry distance (r = 0.97–0.98), and launch angle and dynamic loft (r = 0.98–0.99). Collectively, CHS, ball speed and carry distance serve as the most consistently reliable metrics making them excellent choices for practitioners working with golfers.