Similar to martial arts, the game of Go (Wei Qi/Badouk) has what are known as dan levels. After a player progresses beyond 1k (see kyu level), he becomes first dan, often written as 1d. The idea is that at this point he (or she... there are plenty of dan level females) has ceased to be a student and is now a teacher, sort of like getting your black belt in a martial art. As in martial arts, there are 9 achievable dan levels (1d-9d), with 10d being the theoretical, unattainable level of total perfection. Professional Go players (at least the ones I see playing on TV here in South Korea) are usually in the range of 6d-9d.