The professional go ranks have traditionally been divided into nine levels, with shodan or 1 dan being the initial grade for a student player certified as professional (kishi in Japanese). The ranks go up to 9 dan, the whole system being based on old customs from the Chinese Imperial court. (The imperial court had 1 pin as highest and 9 pin as lowest however) To this day there are nine professional dan levels in China and South Korean as well as in Japan; the same applies in Taiwan. The basic system described at go handicaps is insufficient to provide an accurate ranking, because professional levels are closer together. It is considered inconceivable that any pro should take a four-stone handicap from another.