Correspondence Chess Explained: Rules, Email Chess and How to Play

Correspondence chess is chess played over long distances, with each player taking days rather than minutes to answer. It was traditionally played by post, and today it is mostly played on a correspondence chess server, on a public internet board or by email. Rarer media such as fax, phone or homing pigeon exist.

One of the older documented postal games dates from 1804, when a Dutch army lieutenant-colonel, F. W. von Mauvillon, played an officer in Breda from The Hague. A far larger exchange took place in 1999, when Garry Kasparov played the World Team online. More than 50,000 people from over 75 countries took part, the game lasted four months, and the World Team resigned on 22 October.

How correspondence chess works

A correspondence game is an ordinary game of chess with a very long clock. Servers are normally database-driven and give players a web page for submitting moves, and the transmission method does not matter as long as the move is recorded. Common server limits are one move per 24 hours, or one move every three, seven or fourteen days. The ICCF normal limit is 30 to 60 days for every 10 moves.

The slow pace changes the game. Players can analyse deeply, look things up and plan a long way ahead, so the results show it. In ICCF finals and Candidates games from 2010 to 2013, 82.3 percent of games were drawn, and the share reached 97 percent in 2019. Readers curious about the wider debate on drawn games can read about BAP scoring, one attempt to make draws less attractive.

How to play email chess and postal games

Anyone asking how to play email chess is really asking how to agree three things with an opponent: a notation, a way to keep time and a way to settle disputes. Moves travel as plain text. Because piece letters differ between languages, a numeric notation was devised in which each square is a file digit followed by a rank digit, so 1.e4 reads 5254 and a promotion adds a fifth digit, 1 for a queen up to 4 for a knight. It is the ICCF’s official notation and goes back to about 1803, though algebraic notation is now nearly universal. ICCF guidelines let players use two notations at once if both agree at the start.

Email chess has declined for practical reasons. Viruses made attachments risky, and opponents sometimes claimed not to have received a move. For the same reasons postal and email games have largely moved to servers. The ICCF guidelines of 2017 still allow a tournament director to require that a slow postal game continue by electronic transmission, normally email.

For readers wondering how to play email chess today, the realistic route is a server. Entering a move there triggers an automatic message to the opponent, and the site keeps the clock, the record and the game score.

Correspondence chess rules and time control

Correspondence chess rules follow the FIDE Laws of Chess unless a tournament says otherwise, and the ICCF server rules state it in those words. Several of these correspondence chess rules are specific to the medium.

A draw offer is valid only while it is still the receiving player’s turn to move, and it lapses if that player goes over the time limit. On the ICCF webserver, reflection time is counted in days, and the first 24 hours count as zero. A player may use no more than 50 days for the first ten moves and 100 for the first twenty, and after 20 days on one move each extra day counts double. A player who stays silent for 40 days on a single move is scored as losing. Automatic reminders are sent after 14, 28 and 35 days. Leave is allowed up to 45 days per calendar year, and the final score is reported in PGN.

One rule shows how close the rules sit to computer chess. In ICCF events a position won in a certified tablebase is awarded as a win even if the fifty-move rule would otherwise intervene. The page on computer chess explains what a tablebase is.

ICCF, titles and ratings

The International Correspondence Chess Federation was founded on 26 March 1951 as a new appearance of an association dating from 1945, itself a successor of the IFSB, founded in Berlin in 1928. It is the only correspondence chess organisation affiliated with FIDE. It runs individual and team championships, title norm tournaments and promotion tournaments, in postal and server versions, and it has held Chess960 events since 2011.

The World Correspondence Chess Championship has four stages: preliminaries, semi-finals, a candidates tournament and a final. The first final ran from 1950 to 1953 and was won by Cecil Purdy of Australia. The ICCF awards the titles International Correspondence Chess Grandmaster, Senior International Master, International Master, Correspondence Chess Master and Correspondence Chess Expert. A grandmaster title can be earned by placing first to third in a world final, by two norms across at least 24 games, or by other routes. Casual play does not produce official ratings, although some servers keep their own.

Engines in correspondence chess

Engine rules are the biggest difference between organisers. The ICCF allows human and computer collaboration and permits tablebases, and it describes the result as a hybrid competition of human planning and machine accuracy. Other providers disagree. Lichess prohibits engines but allows an opening book in correspondence games, and Chess.com’s Daily Chess forbids them. The Correspondence Chess League of America runs Traditional games, where engines may not choose moves, and Advanced games, where they may.

How to start

Pick a medium first. A server is the easiest. Read its time limits and engine policy before entering a game, since the same habit can be fine on one site and a ban on another. Settle on a notation, keep your own record of dates and moves, and use the leave allowance sensibly. Those who want titles can look for ICCF events.

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