The Ranks
KGS uses the Japanese rank standard. A beginner is ranked 30 kyu; as they get better, their rank goes down until they reach 1 kyu, which is a decent amateur player. After that, they become 1 dan, and then improve up to 7 dan (9 dan on KGS), which would be the very strongest amateur. Pro ranks on KGS are on a completely different scale on KGS, and are 1 pro dan through 9 pro dan.
In general, the difference between player's ranks is a good indication of the handicap that would give them an even game. For example, if a 2 dan and a 3 kyu play a 19×19 game together, giving the 3 kyu player four handicap stones would make it a good game.
On KGS, kyu ranks are shown with a "k", as in "3k" or "10k", dan ranks are shown with a "d" as in "1d" or "2d", and pro dan ranks are shown with a "p".
How are Ranks Decided?
KGS uses a system that continuously scans all rated games that a user played in the last 180 days to compute the rank for that player. If you have no games, your rank will be shown as a "?". Once you play a single rated game against a player with a rank, you will be given a rank estimate. This estimate will be shown as a rank with a "?" after it. For example, if you beat a 4k player in an even game, you will immediately become "3k?" in rank.
After you play more games, the "?" will disappear from your rank. Exactly when this happens depends on the games you play, but usually once you have two wins against solidly ranked players and two losses against solidly ranked players your "?" will go away.
Only ranked 19×19 games will be used by the rating system. All other games will be ignored.
More details on the math behind the rating system is also available.
Some players choose not to have a rank. If you don't want one, go to "Edit Personal Information" under the "User" menu and uncheck the box next to the word "Rank" in your information window. This will set your rank to be "-", and all games you play will automatically be free (free games are games that are ignored by the ranking system).
Pro ranks are not computed by the rank system. Instead, when somebody has received a professional rank from a real-world go club, the KGS admins will set their KGS rank to be the same value. Thus pro ranks are honorary on KGS, and do not come from playing well on the server.
Special Marks in Ranks
Rank Cheating
There are always people who try to cheat at any system. On KGS, there are people who try to cheat to improve their ranks. The most common system is escaping, that is, leaving instead of accepting the loss when your opponent is ahead. KGS solves this problem by keeping track of how many ranked games you have escaped from; if you have escaped from too many, then some of your escapes will become losses by forfeit. Always try to find your old opponents and finish the games with them or else this will happen to you!
Free, teaching, etc., games are not considered here. If somebody walks away from a non-ranked game when they are behind, then it is really just a very impolite way of saying that they resign.
Other types of cheating are dealt with on a case by case basis. See the KGS Terms of Service for more information.
