In Scotland, the Grand Caledonian Curling Club was founded. The first curling rules were written in 2005: Women's and Men's Curling Championships. Curling has been dubbed the "roarin' game," with the "roar" stemming from the noise made by a granite stone as it moves over the ice. The sport originated in Scotland but has spread worldwide. The first world championship was held at the end of 2004 in Scotland. The event is so called because it is contested by countries instead of individuals or teams. There are two types of events at the world championships: gold medal games and final round matches. In gold medal games, only one team plays against the clock while the rest of the field is inactive. In final round matches, all fields play each other simultaneously. The tournament is split into three stages: Group stage, knockout stage and final ranking stage. During the group stage, which runs for eight days, each country is assigned a number of opponents based on their overall record. They then play against each other within their group, with the top finishers from each group going through to the knockout stage. In the knockout stage, there are four rounds called groups. Each team will be assigned a group based on their placement in the group stage. The group winner is determined in a single-elimination format where the highest ranked team not yet playing knocks out the lower ranked team. The last remaining team wins the group.