Background: In Taekwondo competitions, the rule is that points are scored when the impact of the kick reaches a predetermined threshold of strength. This study aimed to explore the adequacy of the protector and scoring system (PSS) designed to determine taekwondo body scoring based on a reference group model (RGM). Specifically, the kicking impact of the PSS was calculated using data from 188 matches fought during of 2018 Jakarta Asian Games. The RGM was designed based on empirical data by classifying the victory and defeat groups by gender and weight class, and the scoring method was set according to these criteria. Result: The result of this study are as follows. First, there was no difference in the average impact of kicks of taekwondo players by weight class. Second, result of setting up the kick scoring impact standards of taekwondo PSS by classifying the winning and non-winning groups, the kick scoring impact set by the WT was found to be high in all weight classes except 58 kg. Lastly, result of comparing the settings of impact to score according to weight classes, the kick scoring impact standard set by the WT was higher in heavyweight (men's: under 80 kg, + 80 kg, women's: under 67 kg, over 67 kg) than in the lightweight (men's: under 58 kg, under 63 kg, under 68 kg, women's: under 49 kg, under 53 kg, under 57 kg). Conclusion: The kick scoring impact set by the WT was found to be high in all weight classes except for the under 58 kg class defining kick scoring impact based on the standards of WT-certified PSS by classifying the matches into winning and non-winning groups. Finally, as a result of comparing the scoring impact settings according to weight class, the kick scoring impact standard set by the WT was higher for the heavier weight classes than for the lighter weight classes.

Three hundred and forty five matches from the men’s division of the 2017 Muju International Taekwondo Competition were studied to record the instances and nature of point deductions. Deductions were noted in respect to match conditions, match times, positions in court, and the type of deductions. These data were used to record frequencies as well as correlation between events using association rule learning. Firstly, we found the highest frequency of point deductions occurred when an athlete already has lower scores during a match (i.e. when they are losing in the match). Deductions were most numerous during the second round, and when play was in centre-of-court. Point deductions of number 3 were the most common (grabbing or pushing the opponent). Secondly, correlation between point-deductions and certain events were found in the following order: 2 points (out-of-bounds) against a winning contestant in the third round fighting at the outskirts of the court; 4 points (miscellaneous) in the first round to drawn contestants fighting at the centre-of-court; 1 point (falling) against a losing contestant in the third round fighting at the centre-of-court.

In this study, a PageRank model is proposed to overcome the existing problems in estimating the Olympic Taekwondo rankings. For this purpose, PageRank value was calculated by using the results of 144 matches in the Men’s −58 kg class at the World Gran Prix Taekwondo competition. As a result, we identified the possibility of applying the PageRank model to calculate the Olympic Taekwondo ranking. In addition, there was a difference between the rankings calculated by the PageRank method and the Accumulative Point Index System method which is currently used, and the PageRank method was found to be more validity.

Sports injuries frequently occur in athletes during competitive activities and practice routines, and the causes include cumulative fatigue from repetitive training, lack of warm-up exercises, and absence of motivation during competition. We aimed to determine the frequency and characteristics of lower extremity injuries in high school Taekwondo athletes. This study evaluated lower extremity sports injuries in 473 high school Taekwondo athletes. We conducted frequency and cross analyses. The questionnaire tools were developed to identify the characteristics of lower extremity injuries in Taekwondo athletes. Results: For injury by person, thigh injuries and re-injuries were most frequent. In non-contact injury, ankle injuries and re-injuries were most numerous. In the men’s lightweight category, thighs were injured the most in injury by person and ankles suffered the most non-contact injuries. In the men’s heavyweight category, the number of knee injuries was highest in injury by person, and the number of ankle injuries was highest in non-contact injury. In the women’s lightweight category, thighs suffered a higher number of injuries by person, whereas ankles had the highest number of non-contact injuries. In the women’s heavyweight category, thighs had the highest number of injuries by persons, whereas ankles had the highest number of non-contact injuries. The causes of ankle injury in weight classes were different in the two sexes. Conclusion: In this study, we confirmed that the sports damage suffered by student athletes mainly occurs as injuries in training situations without opponents. Our findings could help formulate basic guidelines for preventing sports injury in Taekwondo.

This study aims to define and cluster tennis match types based on how they are played. The research data selected for this study were from the 100th round of 32 matches of the five finals of the 2023 International Tennis Open Tournament. Based on expert knowledge and sports expertise, 27 variables were included across seven areas. Three models were applied and the silhouette coefficient was calculated to identify the optimal number of clusters. A difference test was conducted on the game record variables based on the cluster results. Calculation of the silhouette coefficients for the three models showed that Model 3 (silhouette coefficient: 0.406) had the highest performance. The clustering results for the tennis match types are as follows. First, the NEt Rusher Defensive type, which is defensive and induces net play. Second, the ALl Courter Defensive type, which is either defensive or all-round. Third, the STroke Placement Offensive type, which is aggressive and has strengths in stroke. Fourth, the SErve Placement Offensive type, which is aggressive and has strengths in sub courses. This study’s findings are not only provide basic data to cluster game types in tennis matches but also to contribute to establishing game strategies for each game type, thereby further improving performance.

Background. There is a weakness that the win-loss ranking model in the MLB now is calculated based on the result of a win-loss game, so we assume that a ranking system considering the opponent’s team performance is necessary. Objectives. This study aims to suggest the PageRank algorithm to complement the problem with ranking ...