Smart Game Format
The Smart Game Format (SGF) is a computer file format used for storing records of board games. Go is the game that is most commonly represented in this format and is the default. SGF was originally created under a different name by Anders Kierulf for his SmartGO program.
The first version of SGF, FF![1], was conceived by Anders Kierulf in 1987. It is Appendix A in his Ph.D. thesis. FF![3] was written by Martin Muller in 1993. The current version of the SGF is FF![4] by Arno Hollosi, and is supported by most current SGF readers. FF![2] was never made public.
The main purposes of SGF are to store records of played games and to provide features for storing annotated and analyzed games (e.g. board markup, variations). It is a text-only, tree-based format. The tree structure makes the addition of variations simple. It is also text-based instead of binary for the sake of portability.
Games stored in SGF format can easily be emailed, posted or processed with text-based tools. Most Internet Go server and Go software from 1990 support this format.