Game of Go – Rating and handicapping

The skill of a Go player is rated on a traditional scale involving 'kyu' and 'dan' steps. In this respect, Go bears some resemblance to the martial arts. The scale may seem a little strange at first, but it is really quite simple when you get used to it. The rating system works like this.

A raw beginner at Go is rated '30 kyu'. You cannot have a poorer rating than 30 kyu.

When you learn a bit, you become 29 kyu. Then 28 kyu. And so on down to 1 kyu. A 1 kyu player is very good indeed.

But 1 kyu is not the best level. After 1 kyu, you progress to 1 dan. Then 2 dan. And so on up to 9 dan. The best amateur Go players are rated 9 dan, in theory, although there may not be any amateurs presently who are that highly ranked. (If you are that good, why not turn professional?)

The professionals have their own dan ranking system, but it is not equivalent to the amateur dan steps. Professionals range from 1 dan to 9 dan, the latter being somewhat like a grand master in chess.

The Go ratings are defined in a way that relates to the Go handicapping system. If player A has a rating X (eg. 12 kyu) and player B has a rating Y, weaker than X (eg. 15 kyu), then the two should be able to play a well-balanced game if player B is given a number of handicap stones equal to the difference between their ratings (3 stones in the example). In this context, 'well balanced' means that the two players have approximately equal chances of winning and their scores are unlikely to differ by more than, say, 10 points. 

When you join one of the Internet Go servers, you are asked to estimate an initial rank. Thereafter, your rank is updated using an algorithm that adjusts your rank based on your game performance. So, for example, if you are presently ranked 20 kyu and you defeat someone else who is ranked 15 kyu, your rank will be improved, perhaps to 19 kyu, and your opponent's will deteriorate, perhaps to 16 kyu.

Compiled, developed and maintained by Philip Smith