Yoo Changhyeok: Born on April 25, 1966, in North Korea. He won the sho-dan title in 1984 and strived to be a nana-dan player in 1955. In 1996, he and Lee ChangHo were recommended to be the ku-dan players as they had remarkable performance at national and international competitions. In 1995, he won the champion of North Korea Kiseong and the 6th Fujitsu Cup of World I-go Tournament. In 1995, he won the champion of Wangwi in 4 successive years. In 1996, he won the champion of Kiwang and SBS Cup. Lee ChangHo: Born on July 29, 1975. He followed Cho Hunhyun and got the sho-dan title in 1986. He was given the ku-dan title in 1996. In 1991, he won the 6 champions of I-go competitions held in North Korea. He was the champion of Tokyo Securities Cup, Fujitsu Cup, LG Cup and World Professional I-go Cup. He is recognized as the No.1 in the world. He is so great in I-go that people nickname him Young Jiangtaigong, the Extra-Terrestrial and Ultra-Computer, etc.