But let’s go back to the rating concept. You can play against anyone and increase your rating, very easy. Too easy maybe: in the real world to increase your rating you should participate to official tournaments. For this reason it is very common to find tournaments on-line. Tournaments start when a certain number of people join the tournament which is scheduled at a fixed time and publicized on the site.
Tournaments could be of various types:
- In round-robin tournaments each player plays against every other player in two games (once as white, once as black). The winner is determined by the score but when two players have the same score a tie-break method can be used. The tie-break method widely used for this kind of tournament is the Neustadtl score. A player's Neustadtl score is calculated by adding the sum of the conventional scores of the players they have defeated to half the sum of the conventional scores of those they have drawn against. Round-robin tournaments are simple but they are effective only when the number of players is limited to few users.
- Knock-out tournaments are used when there are a lot of players in order to reduce the time taken by the competition. Players are put into smaller groups and then the winner(s) of that group are combined with winners of other groups to form a new group. The winner(s) of the final group are the winner(s) of the entire tournament. One or more players could advance from each group. If one only has to advance, a tie-break method is used.
- A Swiss tournament goes for a predetermined number of rounds, with all of the players taking part in each round. In each round two players compete head-to-head. All players participate in the entire tournament – none are eliminated. The winner (and top places) of the tournament is based on the final scores of the players. The final score is based on the number of points they accumulated for each round. The tournament lasts for a number of rounds announced before the tournament. After the last round, players are ranked by their score. If this is tied then a tie break score, such as the sum of all their opponents' scores (Buchholz chess rating), can be used. The Buchholz System is in fact the sum of the score of each of the opponents of a player.
When the users of a web site are quite a number, it is common to find teams of players playing against. Not a one-to-one challenge but a many-to-many challenge. The team wins if the score of its members is higher than other teams after the fight. Team members become friends, they exchange information trough dedicated chat.
Also teams can compete in tournaments. In this case the rating is different.
Some game providers allow users to play different chess variants and gain rating also for those games. The most popular chess variants you can find are
- Chess 960
- Reverse (suicide chess)
- Checkers
- Bughouse
