How is Go4Go database compiled?

We at are very proud of the high quality of our game collection. Unlike many other databases that simply accumulate a collection of SGF files from various sources, we take the extra effort to normalise the game information associated with each game record.

  • Tournament Names: Go tournaments are subject to frequent changes. We research the background information of each tournament. We maintain an active list and a discontinued list of tournaments and related tournaments are cross-referenced. Their names are always used consistently.
  • Player Names: player names are always used consistently. Please read 'how player names are translated' for details.
  • Player Ranks: unfortunately professional ranks nowadays do not reflect the actual strengths of players. This piece of information is provided for reference only and some may be slightly inaccurate (getting promoted is no longer a major event so verifying rank details become increasingly difficult).
  • Game Dates: always records the exact playing date of each game. There are special situations that require more attention:
    • Traditionally, key Japanese games were held over multiple days (to ensure high-quality game and to give the sponsors, normally newspapers, room to develop storylines). Even in modern days big games (e.g. Japanese Kisei title match games) last for two days (with each player having up to 8 hours reserved time). The game dates recorded in such cases are for the first days.
    • In several tournaments (such as Japanese NHK Cup and Japanese Ryusei) games are played in private first and televised later to suit TV schedules. may record the broadcasting dates (the actual playing dates are often hard to independently verify). This is always done consistently and clearly indicated in individual tournament pages.
  • Game Results: game results are always recorded using the standard way as defined by the SGF Specification. Valid results include:
    • B+R/W+R (win by resignation)
    • B+T/W+T (win by time)
    • B+F/W+F (win by forfeit) - this does happen occasionally in major professional tournaments, when players took a ko back without finding a threat, or when they attempted to play two moves in a row!
    • B+???/W+??? where ??? are the winning margins in the units of point or equivalence. For games using Chinese rule, B+3.5 actually means: black wins by 1 and 3/4 stones.
    • Void - when games ended in rare positions such as Triple Ko, Quadrupal Ko or even Eternal Life, or when they were interrupted by other reasons.
    • Draw - when komi was not in use this may be a valid outcome.
  • Duplicated Games: each game in Go4Go database carries a unique identification as defined by a Dyer Signature. This ensures that duplicated games never have a chance to enter the database.