Correspondence Play in Chess: Meaning, Time Limits, Notation

Correspondence play is chess in which the players move at a distance and take days, not minutes, over each move. The phrase covers games by post, by email and on web servers, and it is the setting for correspondence chess as a competitive discipline with its own federation, titles and tournaments.

How the clock differs

In live chess the clock runs in minutes and hours. In correspondence play the unit is the day. Common limits on servers are one move per 24 hours, or one move every three, seven or fourteen days, and the ICCF normal limit is 30 to 60 days for every ten moves. Under ICCF guidelines valid from 2017, the reflection time on the webserver is counted in days rather than hours, a player who stays silent for 40 days on one move loses the game, and leave of up to 45 days a calendar year is allowed.

Media

Postal play travels by traditional mail. Email play sends move lists as text and has declined, partly because of viruses and partly because opponents sometimes claimed not to have received a move. Servers are database-driven, with a web interface for submitting moves, and the exact means of transmission does not matter as long as each move is recorded. Fax, phone and homing pigeon have all been used, but rarely.

Notation

Piece letters differ between languages, so international postal play long used ICCF numeric notation. Each square gets two digits, the file first and the rank second, and a move is the start square followed by the end square. The move 1.e4 is therefore written 5254. A fifth digit marks a promotion, with 1 for a queen, 2 for a rook, 3 for a bishop and 4 for a knight. Use of the system has declined, since most games are now entered through a graphical board and algebraic notation is nearly universal.

Engines and rules

The most visible difference from live play is the rule on computers. The ICCF allows engines and tablebases in its events, while some providers ban them, so the engine policy is worth reading before entering a game. The rest of the story is covered in the full page on correspondence chess, which also lists the main rules and titles. For the technical side of engines and endgame data, see computer chess and the glossary entry for a tablebase.

A short history of the practice

One of the oldest documented postal games was played in 1804 between Lieutenant-Colonel F. W. von Mauvillon in The Hague and one of his officers in Breda. International organisation came later. The Internationaler Fernschachbund was founded in Berlin on 2 December 1928, and its line of succession leads through the International Correspondence Chess Association of 1945 to the International Correspondence Chess Federation (ICCF), founded on 26 March 1951. The ICCF is the only correspondence chess body affiliated with FIDE. The decline of traditional postal chess began at the end of the twentieth century, around the time chess programs became widely available.

Titles and championships

The ICCF awards International Master, Senior International Master and International Correspondence Chess Grandmaster, which it treats as equivalents of FIDE’s over-the-board titles, and it also has the lower Correspondence Chess Master and Correspondence Chess Expert titles. One route to the grandmaster title is two grandmaster norms in international title tournaments with a total of at least 24 games, and finishing 1 to 3 in a World Championship final is another. The first World Correspondence Championship final ran from 1950 to 1953 and was won by Cecil Purdy of Australia. Hans Berliner of the United States won the fifth, which ran from 1965 to 1968; he was also an over-the-board International Master. The championship has four stages: preliminaries, semi-finals, a candidates tournament and the final. A final takes years to finish, and events overlap, so the 17th championship was still undecided when the winner of the 18th was announced.

The numeric notation in more detail

Numeric notation is old. A German professor, J. W. D. Wildt of Göttingen, devised it around 1803, Johann Koch used it some 25 years later and it is sometimes called Koch notation, and in Russia it carries the name of Ivan Savenkov, who supported it in 1877. Because it names squares only, it does not say which piece moves and does not mark captures or checks. Castling is written as the king’s move alone: 5171 for White kingside and 5131 for White queenside, 5878 and 5838 for Black. A pawn going from f7 to f8 and becoming a rook is 67682.

Draw offers and claims

A draw offer in ICCF play is not tied to a move number. Under the ICCF guidelines an offer is valid as long as it is still the receiving player’s immediate move, and it becomes void once that player exceeds the time limit and is no longer the one on move. The tablebase rule is also written down. If a position is not solvable by the certified ICCF tablebase, the fifty-move rule of the FIDE Laws applies even when a solvable position would arise right after the fiftieth move, but a player who claims a solvable won position before the draw counts gets the win.

Draws are common. In top ICCF games from 2010 to 2013, 82.3 percent of 1,512 games were drawn, and the rate reached 97 percent in 2019. The ICCF allows human and computer collaboration, even in the World Championship, and permits reference material such as endgame tablebases, which explains much of that figure. Chess.com Daily Chess prohibits chess engines and analyses winners’ games for fair play, and the USCF likewise prohibits chess-playing algorithms in its rules.

Scale and curiosities

Correspondence play has produced some of the largest games on record. In 1999, Kasparov against the World drew more than 50,000 participants from over 75 countries, who chose moves by plurality vote over four months; Kasparov called it the greatest game in the history of chess. The first Chess.com Daily Chess Championship in 2018 had just over 7,000 players, and by 2023 the organiser capped entries at 35,000. One story concerns Humphrey Bogart, who played postal games against American soldiers: the FBI once intercepted his mail, fearing the notation was a code.

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