Correspondence chess

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Correspondence chess is chess played over long distances. Instead of meeting at a real board, players share moves through mail, email, a dedicated server, or online forums. It can also be done by fax, pigeons, or phone, but those are rare today. It differs from over-the-board (OTB) chess, where players sit at the same board at the same time, and from most online real-time chess.

Move transmission and game length vary. A postal game between countries can take years, while server-based or email games usually last days to months. Players often have many games at once, sometimes more than a hundred. There is no strict per-move time limit, but a common rule is about one day per move, plus transmission time. High-level correspondence games can last more than a year.

Tools, rules, and organizations differ by form. Some forms allow using books and chess databases; others vary on whether engines are allowed. The rise of powerful engines changed the scene, and enforcement of engine use is uneven. The International Correspondence Chess Federation (ICCF) is the main international body linked to FIDE and it allows human play guided by computer assistance, even in World Championship events. Other groups run postal or online play, such as national federations and servers like IECG, LSS, FICGS, and IECC. The ICCF awards titles such as International Master and International Correspondence Chess Grandmaster and runs the World Correspondence Chess Championship.

Daily chess and casual server play are popular today. Postal chess has largely been superseded by server-based correspondence, but casual play on servers remains common, with databases, ratings, and forums. A newer development is daily chess, which blends online access with the slower, turn-based nature of traditional correspondence chess. Daily chess events began in 2018, and by 2023 they attracted tens of thousands of players.

Notable players from the world of OTB have participated in correspondence as well. For example, Paul Keres and former world champions Alexander Alekhine and Max Euwe competed in correspondence games, and Kasparov played a famous internet game called Kasparov versus the World in 1999.

In short, correspondence chess lets people anywhere in the world play many thoughtful games at a slower, longer pace, using a mix of traditional and modern methods.