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 AAU sport, and there have been national competitions and tournaments ever since. The United States formed an Olympic team and competed in the 1964 Summer Olympics, which it continues to do to this day. Judo is now practiced by and estimated 100,000 American men, women, and children (25,000 registered in either the USJA, USJF, and USA Judo). America's first major contact exposure to judo came through President Ulysses S. Grant in 1879. He was in Japan for a state visit and observed a judo demonstration. In 1889, Kanō Jigorō gave a lecture on the philosophy of judo to several Americans;