Egbert Rittner is a 6 dan amateur player from Hamburg. He used to be one of the strongest players in Germany, winning the German Go Championship six times between 1987 and 2001. Plays on KGS as user kimball.
An episode reported by the DGoZ: Rittner is playing another high dan player and a kyu player is watching. A move by Rittner is commented by the kyu player: "I would have played there, too." Answer Rittner: "Sure, indeed it was a mistake." (In german: War ja auch ein Fehler).