## 4 Discussion
As the ground contact time in a 180\({}^{\circ}\) COD is greater than that of a 45\({}^{\circ}\) COD [17], the proportion of actual COD time in the CODTT in the 180\({}^{\circ}\) COD is higher, resulting in the higher predictability of the CODTT variables of the Pro-agility 0-10 m test. It can be inferred that the relationship between the CODD and the COD angle is almost consistent with the relationship between the ground contact time of the cut action and the cut angle. From the above analysis, the CODTT mainly consists of the actual COD action and a short sprint time. Using the CODTT as a basis for evaluating the athlete's actual COD ability may not be appropriate. As an essential component of the CODTT, the CODD is independent of the straight sprint time variable and is related to the ground contact time of the cut action. Hence, it can beinferred that CODD might accurately reflect an athlete's actual COD ability, suggesting that employing CODD as an indicator for assessing an athlete's actual COD ability could represent a more scientifically rigorous evaluation approach. Assessing athletes' COD ability is the prerequisite for mastering their COD ability characteristics and devising tailored training plans. Identifying the strengths and weaknesses of athletes' COD abilities is a vital test goal. A comparison of the standardized Z-score of CODTT and CODD revealed differences of 22% and 13% in the classification of athletes' COD ability on the left and right sides, meaning that the Z-score changed from positive to negative or negative to positive. These findings align with previous research [5; 10; 11]. A plausible explanation for these variations may include substantial short sprint distances within the COD tests, allowing athletes to capitalize on their proficiency in straight sprints to minimize CODTT. However, their actual COD ability still needs improvement. This need for improvement was confirmed in a study that divided 49 professional male rugby players into fast and slow groups based on their 0-5 m sprint times, showing that the fast-group athletes achieved significantly better results in the Zigzag test than the slow group [18]. Another study compared the Zigzag ability and 20 m sprint ability among rugby athletes spanning different age groups, including U15, U17, U20, and adults [19]. The findings revealed that CODTT and 20 m sprint time increased with age across all age categories. In contrast, CODD exhibited an inverse trend, declining as athletes advanced in age. The low efficiency of actual COD actions might be due to a lack of targeted COD training, leading to the athletes' inability to improve their deceleration, braking, and re-acceleration abilities [2]. Hence, relying on the CODTT for evaluating an athlete's COD performance could result in incorrect judgments. The asymmetry of an athlete's COD ability on both sides can serve as a valuable reference for predicting the risk of sports-related injuries, monitoring post-injury recovery progress, and developing targeted training regimens to enhance COD performance. A previous study demonstrated that the asymmetry index based on CODD in the 505 agility test was higher than CODTT, and the proportion of COD ability asymmetry based on CODD was significantly higher than CODTT [11]. This study is similar to the above findings, with the asymmetry index and the proportion of COD ability asymmetry based on the CODD being higher than the CODTT. This phenomenon may be due to the differences between the CODTT and CODD in reflecting actual COD ability [11], as confirmed by previous empirical research. Moreover, a study that involved implementing the 505 agility test on a female athlete with a history of a 2-year-old ACL injury on her right leg revealed that the difference in left and right leg COD ability based on CODTT and CODD was only 0.1. However, CODTT's asymmetry index was much lower than CODD [20]. The above study, combined with video analysis technology, indicated that the 0.1 s mainly came from the actual difference in left and right leg COD ability.