Factors of winning medals in international soft tennis events

  • Seiji Kusubori Associate professor with Faculty of Bioresource Sciences, Prefectural University of Hiroshima, Shohbara City. Member of governing board with Japanese Society of Science in Soft Tennis, Hachi-Oji City, Japan
  • Toshimitsu Tanaka Member of governing board with Japanese Society of Science in Soft Tennis, Hachi-Oji City, Japan. Member with International Soft Tennis Association, Dongin-Dong Jung-Gu Daegu, Korea.
Keywords: soft tennis, international event, medal winning, decision tree


Soft tennis has four major international events, and to date, 29 official international events have been held. During this period, 576 medals have been awarded. In this study, a two-stage analysis was conducted to explore the factors that contribute to the awarding of medals. Due to the highly skewed distribution of medals, decision tree induction was employed. First, five potential variables were examined for the 10 countries that have experienced medal awards. The results showed that the "host" effect is not a factor for winning medals, but just a norm of international soft tennis events due to the data bias caused by extreme host concentration. On the other hand, we found that participation in at least 16 times international events is necessary to win a medal. An interesting result for Chinese Taipei (CTP) was found that the court surface type is “hard” or not was a contributing factor for winning more medals. In the second step, we examined the distribution of gold medals for the top four countries those have experienced gold medal award. The results showed that South Korea (KOR) has won more gold medals on clay courts, and CTP on hard courts than the other courts, respectively. This study determines the effect of court surfaces on winning medals at a national level. It was also found that KOR has won more gold medals at the World Championships and Asian Games than at the other international events. Japan, on the other hand, has won more gold medals at the Asian Championships.


Balmer N.J., Nevill A.M., & Williams A.M. (2001). Home advantage in the Winter Olympics (1908–1998). Journal of Sports Sciences, 19(2), 129-139. https://doi.org/10.1080/026404101300036334

Balmer N.J., Nevill A.M., & Williams A.M. (2003). Modelling home advantage in the Summer Olympic Games. Journal of Sports Sciences, 21(6), 469-478. https://doi.org/10.1080/0264041031000101890

Balmer N. J., Nevill A. M., & Lane A. M. (2005). Do judges enhance home advantage in European championship boxing?. Journal of Sports Sciences, 23(4), 409-416. https://doi.org/10.1080/02640410400021583

Bernard, A. B., & Busse, M. R. (2004). Who wins the Olympic Games: Economic Resources and Medal Totals. The Review of Economics and Statistics, 86(1), 413-417. https://doi.org/10.1162/003465304774201824

Celik B. & Gius M. (2014). Estimating the determinants of Summer Olympic Game performance. International Journal of Applied Economics, 11(1), 39-47

Chinese Taipei National Sports Medal and Scholarship Award (2015). Retrieved January 20, 2021, from https://gazette.nat.gov.tw/EG_FileManager/eguploadpub/eg021175/ch05/type1/gov40/num12/Eg.htm

Corral, J. (2009). Competitive balance and match uncertainty in Grand-Slam tennis: Effects of seeding system, gender, and court surface. Journal of Sports Economics 10(6), 563-581. https://doi.org/10.1177/1527002509334650

Cross, R. (2002a). Measurements of the horizontal coefficient of restitution for a superball and a tennis ball. American Journal of Physics, 70(5), 482-489. https://doi.org/10.1119/1.1450571

Cross, R. (2002b). Grip-slip behavior of a bouncing ball. American Journal of Physics, 70(11), 1093-1102. https://doi.org/10.1119/1.1507792

Cust, E. E., Sweeting, A. J., Ball, K., Anderson, H., & Robertson, S. (2019). The relationship of team and individual athlete performances on match quarter outcome in elite women’s Australian Rules football Journal of Science and Medicine in Sport, 22(10), 1157-1162. https://doi.org/10.1016/j.jsams.2019.05.004

Date, K. (2018). Court surface prevents Japanese tennis players from world top ranking opportunity [Unpublished master’s thesis]. Waseda University, Tokorozawa, Japan (in Japanese).

Fister, I., Fister, D., Ljubic, K., Zhuang, Y., & Fong, S. (2014, September). Towards automatic food prediction during endurance sport competitions. In 2014 International Conference on Soft Computing and Machine Intelligence (pp. 6-10). IEEE. https://doi.org/10.1109/ISCMI.2014.30

Forrest, D., Sanzb, I., & Tena, J.D. (2010). Forecasting national team medal totals at the Summer Olympic Games. International Journal of Forecasting, 26(3), 576–588. https://doi.org/10.1016/j.ijforecast.2009.12.007

Gschwend, M., & Krumer, A. (2021): On the importance of fixed effects over a short period of time when using sports data: a lesson from home advantage in alpine skiing. European Sport Management Quarterly, 23(5), 1291-1303. https://doi.org/10.1080/16184742.2021.1993297

Hastie, T., Tibshirani, R., & Friedman, J. (2009). The Elements of Statistical Learning: Data Mining, Inference, and Prediction (2nd ed.). Heidelberg: Springer.

Hoffmann, R., Ging, L. G., & Ramasamy, B. (2004). Olympic success and ASEAN countries: Economic analysis and policy implications. Journal of Sports Economics, 5(3), 262-276. https://doi.org/10.1177/1527002503261826

Holder, R. L., & Nevill, A. M. (1997). Modelling performance at international tennis and golf tournaments : is there a home advantage?. The Statistician, 46(4), 551-559

Hughes, M., & Clark, S. (1995). Surface effect on elite tennis strategy. In T. Reilly et al. (Eds.), Science and Racket Sports (pp. 272-277). New York: E & FN Spon.

Hughes, M., & Franks, M. (2004). Notational analysis - a review of the literature. In M. Hughes & M. Franks (Eds.), Notational Analysis of Sport (2nd ed.) (pp. 59-106). London: Routledge.

Ida, H., Kusubori, S., & Ishii, M. (2005). Kinematics and kinetics of the racket-arm during the soft-tennis smash under match conditions. Journal of Applied Biomechanics, 21(4), 334-347.

Inaba, Y., Tamaki, S., Ikebukuro, H., Yamada, K., Ozaki, H., & Yoshida, K. (2017). Effect of changing ball material from celluloid to plastic on the post-collision ball trajectory. Journal of Human Kinetics, 55, 29-38. https://doi.org/10.1515/hukin-2017-0004

Japan Soft Tennis Federation web site (n. d., a). Retrieved June 7, 2020, from https://www.astf.asia/files/organization/Constitution_of_ASTF_b.pdf.

Japan Soft Tennis Federation web site (n. d., b). Retrieved August 4, 2023, from https://www.jsta.or.jp/wp-content/uploads/international/en/schedule-i.html.

Kawabata, I. (2008). What is datamining? In An introduction to datamining (H. Toyota, ed.). Tokyo: Tokyo Tosho (in Japanese).

Koning, R. H. (2005). Home advantage in speed skating: Evidence from individual data. Journal of Sports Sciences, 23(4), 417-427. https://doi.org/10.1080/02640410400021625

Koning, R. H. (2011). Home advantage in professional tennis. Journal of Sports Sciences 29(1), 19-27. https://doi.org/10.1080/02640414.2010.516762

Loh, W. Y. (2008). Classification and regression tree methods. In F. Ruggeri et al. (Eds.), Encyclopedia of Statistics in Quality and Reliability (pp. 315–323). Chichester, UK: John Wiley & Sons.

McHale, I. & Morton, A. (2011). A Bradley-Terry type model for forecasting tennis match results. International Journal of Forecasting, 27(2), 619-630. https://doi.org/10.1016/j.ijforecast.2010.04.004

Morgan, S., Williams, M. D., & Barnes, C. (2013). Applying decision tree induction for identification of important attributes in one-versus one player interactions: a hockey exemplar. Journal of Sports Sciences, 31(10), 1031-1037. https://doi.org/10.1080/02640414.2013.770906

Nevill, A. M., Holder, R. L., Bardsley, A., Calvert, H., & Jones, S. (1997). Identifying home advantage in international tennis and golf tournaments. Journal of Sports Sciences, 15(4), 437-443. https://doi.org/10.1080/026404197367227

Gschwend, M., & Krumer, A. (2021). On the importance of fixed effects over a short period of time when using sports data: a lesson from home advantage in alpine skiing. European Sport Management Quarterly, 23(5), 1291-1303. https://doi.org/10.1080/16184742.2021.1993297

O'Donoghue, P., & Liddle, D. (1998). A notational analysis of time factors of elite men's and ladies' singles tennis on clay and grass surfaces. In A. Lees et al. (Eds.), Science and Racket Sports Ⅱ (pp. 241-246). New York: E & FN Spon.

Ofoghi, B., Zeleznikow, J., MacMahon, C., & Raab, M. (2013). Data mining in elite sports: a review and a framework. Measurement in Physical Education and Exercise Science, 17(3), 171–186. https://doi.org/10.1080/1091367X.2013.805137

Omote & Japan Soft Tennis Association (1985). Nihon Teikyu Shi [The history of tennis in Japan] (in Japanese).

Omote & Japan Soft Tennis Association (1986). Zoku Nihon Teikyu Shi [A Sequel: The history of tennis in Japan] (in Japanese).

Pettigrewa, S., & Reicheb D. (2016). Hosting the Olympic Games: An overstated advantage in sports history. The International Journal of the History of Sport, 33(6-7), 635-647. https://doi.org/10.1080/09523367.2015.1132201

Ross, S. M., Smit, E., Yun, J., Bogart, K. R., Hatfield, B. E. & Logan, S. W. (2021). Exploring the interaction of disability status and childhood predictors of physical activity and sport participation: An exploratory decision tree analysis. Adapted Physical Quarterly, 38(2), 248-267. https://doi.org/10.1123/apaq.2020-0027

Scelles, N., Andreff, W., Bonnal, L., Andreff, M., & Favard P. (2020) Forecasting national medal totals at the Summer Olympic Games reconsidered. Social Science Quarterly, 101(2), 697-711. https://doi.org/10.1111/ssqu.12782

Reid, M., Crespo, M., Santilli, L., Miley, D., & Dimmock, J. (2007). The importance of the International Tennis Federation's junior boys' circuit in the development of professional tennis players. Journal of Sports Sciences, 25(6), 667-672. https://doi.org/10.1080/02640410600811932

Reid, M., Crespo, M., & Santilli L. (2009). Importance of the ITF Junior Girls' Circuit in the development of women professional tennis players, Journal of Sports Sciences, 27(13), 1443-1448. https://doi.org/10.1080/02640410903037714

Shinohara, H. (2019). Soft tennis: Double forward, Gijutsu Hen [Soft tennis: Techniques for double forward games]. Tokyo, Japan: Baseball Magazine.

Takahashi, H. & Kiku, K. (2013). A Study on “Publicness” of Sport Policy: Referring to the Sport Policies in Korea and China. Bulletin of Nara University of Education, 62(1), 121-133 (in Japanese).

Tanaka, T. (2019). Digital Archive. Soft Tennis Homepage. Retrieved June 7, 2020, from http://www.soft-tennis.org/record/overseas/index.html.

Tan, T. C., & Houlihan, B. (2012). Chinese Olympic sport policy: Managing the impact of globalization. International Review for the Sociology of Sport, 48(2), 131-152. https://doi.org/10.1177/1012690212445169

Ultimate Tennis Statistics (n. d.). Retrieved April 23, 2022, from https://www. ultimatetennisstatistics.com/topPerformers

Vagenas, G. & Vlachokyriakou, E. (2012). Olympic medals and demo-economic factors: Novel predictors, the ex-host effect, the exact role of team size, and the ‘‘population-GDP’’ model revisited. Sport Management Review, 15(2), 211-217. https://doi.org/10.1016/j.smr.2011.07.001

Willoughby, K. A., & Kostuk, K. J. (2005). An analysis of a strategic decision in the sport of curling. Decision Analysis, 2(1), 58-63. https://doi.org/10.1287/deca.1050.0032

Written, I. H., & Frank, E. (2005). Data Mining. Practical Machine Learning Tools and Techniques (2nd ed). California: Morgan Kaufman Publishers.

How to Cite
Kusubori, S., & Tanaka, T. (2023). Factors of winning medals in international soft tennis events. International Journal of Racket Sports Science, 5(1). Retrieved from https://journal.racketsportscience.org/index.php/ijrss/article/view/84