## 4 Discussion
Our results also offer a reassuring finding by indicating that the mean difference between devices is approximately 1.4 km/h for both throwing and kicking. This relatively small difference is significant, as it highlights the close correlation between the Bushnell and Stalker radar guns, suggesting that the Bushnell radar is a reliable tool for measuring ball speed with minimal deviation from the reference standard. This difference is smaller than the 3 km/h mean difference observed in comparisons between the Pocket radar and Speedtrack X radar [17], as well as the bias of 2.26 to 3.19 km/h found in the study comparing the Stalker with the Pocket radar [11]. However, the Bland-Altman analysis in the present study revealed that the limits of agreement between the Stalker and Bushnell radar guns were 4.80 km/h and \(-\)2.02 km/h for the ball speed throw. This variability represents approximately 7.5% and 3.2% of the mean speeds, which, while significant, is not unexpected in the context of radar measurements [24]. Users need to understand that such differences may have practical implications depending on the sensitivity of the application. For instance, rehabilitation practitioners could use this device to track recovery progress in throwing or kicking mechanics, using the Bushnell radar to monitor speed gains while accounting for this minor bias. In these settings, the radar's lower cost and portable nature may outweigh the need for extreme precision, offering therapists a convenient way to assess patient readiness for sport re-entry or workload increases based on movement velocity trends. While our research focused on a narrow range of ball velocities (29-102 km/h), representing only part of the velocity range that the tested guns are capable of measuring (up to 177 km/h), no adverse effect on the agreement between the two radars was observed. This finding is particularly important because it suggests that the high level of agreement between the devices is likely to hold across a broader range of speeds, although further research is needed to confirm this across the entire operational range of the devices. The narrow focus on this specific velocity range was intentional, as it aligns with the typical speeds observed in many sports activities such as soccer, baseball, and cricket [24]. However, extending the analysis to include higher velocities, such as those seen in elite-level tennis serves, would provide more comprehensive insights regarding the performance of these devices under different conditions. Future studies would benefit from exploring the consistency of these devices across a wider range of speeds, particularly in high-velocity applications, such as elite tennis or baseball, where ball speeds frequently exceed 100 km/h [16]. Assessing radar accuracy at much higher speeds would provide a greater understanding concerning the devices' reliability across their full operational range, improving their generalizability to diverse sports settings. Moreover, in youth coaching contexts or community sports programs, where resources are often limited, the Bushnell radar's affordability and ease of use make it an attractive option. By adjusting speed measurements by the approximate 1.4 km/h difference, practitioners can confidently use this device to offer feedback and set developmental goals for young athletes. Such applications highlight the practical benefits of using budget-friendly technology in broadening access to reliable performance monitoring, enhancing the ability to support athlete development, and making advanced feedback tools more accessible across various levels of sport. Naturally, conditions related to the reference criterion and device placement may have resulted in minor variations in the outcomes. Still, these variations had no meaningful impact on the overall agreement of the devices.