Rank in Judo are ranked in ascending numerical order. The ninth ("kudan") and tenth degree black belt ("jūdan") and, theoretically, those higher, have no formal requirements. Only 15 individuals have been promoted to the rank of Kōdōkan 10th dan. On January 6, 2006, three individuals were promoted to this rank simultaneously: Daigo Toshirō, Ichirō Abe, and Ōsawa Yoshimi. This is the most ever at the same time, and the first in 22 years. No one has ever been promoted to a rank higher than 10th "dan", but in theory the Judo rank system is not limited to 10 degrees of black belt. The
Judo in the United States wrestling. Although Yoshiaki threw him time after time, Graft continued to get up. Finally, Yoshiaki decided that he would do mat work with Graft, since there seemed to be no end to the match. Yoshiaki got an armlock on Graft, but the wrestler would not give up. Yoshiaki kept up the pressure until Graft groaned as his arm came close to breaking. President Roosevelt was impressed and took judo lessons. After leaving office, he kept mats in his home. He studied judo for about a year, earning a brown belt. Through the help of the president, Yoshiaki taught judo at