Dr. David Matsumoto
IJF Researcher and USJF Hall of Fame
8th Dan
Blue Judogis may Bias Competition Outcomes David Matsumoto, Jun Konno, Stephanie Hata and Masayuki Takeuchi Abstract In this study we investigated the existence of a win bias in judo competition as a function of judogi color. We analyzed the results of four major international competitions-the 2001, 2008, and 2005 World Championships, and the 2004 Athens Olympic Games-in terms of whether or not athletes were more likely to have won their matches when wearing the blue judogi. The results indicated a statistically significant bias in winning percentage for male athletes who wear the blue judogi, but not for females. This bias increased within a tournament from beginning to end, and across years.