By getting experience with Go and learning new concepts a player gets a deeper and deeper understanding of the game. But is there a way to measure one's skills and playing strength?
Traditional Go ranks
From the article about history of Go we know that in Japan during the Edo period Go game gained an official recognition of the royal court. The first rank system was established then. Initially it consisted of master ranks called dan. The lowest grade was 1 dan and the highest was 9 dan. Achieving 9 dan indicated an outstanding mastery. For centuries there was always at most one 9 dan player at a time.
Later the students’ ranks called kyu were also added to the system. The highest student grade was 1 kyu. Players with lower skills were given grades of 2 kyu, 3 kyu and so on. Starting from the 19th century this rank system was also applied to martial arts. That's why some people who are new to Go might have already heard of kyu and dan ranks.
Handicaps in Go
In Go the rank system is closely connected with so-called handicap games. It might happen that two players of different level come to play a game. The stronger player is very likely to win. How to make the game more exciting for both players? The stronger player can let the weaker player put a few stones on the board at the start of the game. Then initially the weaker player has an advantage and the stronger player needs to do his best to still win the game.
Handicap Go games have been popular for centuries. The rank system was established in a way that the players would know how many handicap stones should be put according to the rank difference. For example, if a 5 kyu player plays against 2 kyu, then the 5 kyu player would take Black stones and put three handicaps at the beginning. Only then, the opponent would make the first move.
In the modern times there are organized both kinds of Go tournaments: with handicaps and with all games being even (without handicaps). The most important tournaments are played without handicaps. However, most games on Go servers are played with handicaps if the opponents' ranks differ.
Professional Go players
The Go organizations in the Far East award the strongest players with professional titles. A status of a professional Go player is very prestigious. Professional players usually commit their whole life to Go. They earn money by teaching Go, they are invited to the elite tournaments with big prizes and they engage themselves in various ways of promoting the game.
To become a professional Go player one needs to pass an exam. Most often it is a tournament where only the strongest amateurs are invited. In China, Japan, South Korea and Taiwan each year such a tournament is being organized and only a few players who take the highest places achieve professional certificates.
In the West currently only two professional systems exist - one in North America and one in Europe.
Modern Go ranks
Each Go organization decides on the details of its rank system on its own. However, the basic points are common for all the organizations:
- There is a distinction between amateur players and professional players. In general, professional players are much stronger than amateurs. However, some of the amateur players, mostly the ones striving to become professionals, may sometimes beat professionals.
- For the amateur players a kyu-dan rank system is used. The lowest grade differs among the Go organizations. In EGF it is 30 kyu, in AGA it is 25 kyu. Players with rank up to 20 kyu are considered beginners. Players between 19 and 10 kyu are assessed as pre-intermediates. Players from 9 to 1 kyu are called intermediate amateurs. Advanced amateurs hold dan grades. The highest amateur grade in European Go Federation (EGF) and in American Go Association (AGA) is 7 dan.
- For the professional players a separate dan rank system is used. The lowest grade is 1 professional dan and the highest is 9 professional dan. Mostly, even the strongest amateurs with a rank of 7 dan are weaker than 1 professional dan players.
How are the Go ratings calculated?
In both - EGF and AGA - Go ratings are based on a point system. For example, in the system used by EGF a player needs to have a rating of at least 2050 points to be called 1 dan. For getting every next grade one needs additional 100 points of rating. It means that to become 2 dan one needs 2150 points, to become 3 dan one needs 2250 points. And to be 1 kyu the rating of at least 1950 points is needed.
During official Go tournaments every game is counted to the rating. The winner of a game is going to get a specific number of rating points and the loser will lose a number of points. A statistical formula is applied to count how much a player gains or loses. The formula takes into account the ratings of both players. For example, if you beat someone much stronger than you, you get around twice as many points as if you beat someone at your level. If you beat someone weaker, you also gain something but not much.
Ranks on Go servers
If you play Go online, your server will also assign you a rank. Go servers use a kyu-dan system. Each Go server has its own way of calculating what rank which player should get. You might have wondered: if you have a rank on a Go server, does it mean that you should have the same rank when playing on face-to-face tournaments? The answer is: the rank systems used by Go servers are a bit different than the rank systems of EGF, AGA or other Go organizations. It might happen that in EGF you are ranked as 5 kyu but on a Go server you are playing as 3 kyu, or the other way around.
Let’s say you have been only playing Go online. When you go to your first face-to-face tournament, you are not sure with what rank you should play. Then the organizers of the tournament will probably ask you about your rank on a Go server. Below you can find a table, which can tell you roughly what rank you should be assigned with, based on your rank on a Go server. There are included the most popular playing platforms in the West: OGS, KGS and IGS (also known as Pandanet Go Server). And the most popular western Go organizations: AGA (United States) and EGF (Europe).
The table was made based on a survey from March and April 2018.
The original table that includes more servers can be found here.
Adjustments to Go rating systems
All Go servers and Go organizations aim at making their rank and rating systems precise and similar to the other ones. Comparisons like the one shown in the table above are based on statistical analyses. In January 2021 the Online Go Server (OGS) made a significant change in their rating system to make it correspond well to the ranks assigned by EGF and AGA. You can read about it more on the OGS forum.
EGF also applied some changes in their rating system in 2021. The managers of the system realized that over the decades a slow deflation of rating points is happening. It means that for example an average 1 dan player from 2020 is a little bit stronger than an average 1 dan player from 1990. They decided that one constant in a formula used for calculating rating needs to be fine-tuned. On the 4th of April 2021 the change was put into effect. All the tournament results from the last decades were recalculated. As a result all players got a little increment of rating points. Most often it was something around 10 to 60 additional points.