1998-1-5 last update, 1997-9-13 first day
Robert Jasiek, jasiek@berlin.snafu.de

Basic Comparison

Rule Sets

CHN : Chinese Weiqi Association, 1988, mainland China
JAP : Nihon Kiin, 1989, Japan
Ing : Ing's SST rules, 1991
Simple : Simple Rules, 1997
IGS : Internet Go Server
AGA : American Go Association, 1991

Properties

GENERAL	Simple	AGA	Ing	CHN	JAP	IGS
designed for professionals	no	no	yes	yes	yes	no
widely used by amateurs	no	yes	yes	yes	yes	yes
recommanded for beginners	yes	no	no	no	no	no
logical	yes	yes	no	no	no	no

designed for professionals: maintenance of professional tradition strongly characterizes rules' concept
widely used by amateurs: applied by many amateurs for informal or tournament games
recommanded for beginners: simple conception, easy and quickly understood
logical: no contradiction, handles any board position, no special exceptions
further information

SETUP	Simple	AGA	Ing	CHN	JAP	IGS
normal even game komi	not set	5.5	8	5.5	5.5	5.5
free handicap	yes	yes	yes	no	no	no

normal even game komi: typical value for compensation points for white in even game; 8 komi for Ing resulting in a tie give black the win; 5.5 komi for CHN are counted as 2.75 half count komi
free handicap: handicap stones may be placed on any board points; else Japanese handicap on handicap points is used
definitions, game end, game end classification

ALTERNATION	Simple	AGA	Ing	CHN	JAP	IGS
suicide	yes	no	yes	no	no	no
ko	PSK	SSK	Ing	void	void	void

suicide: allowance of self-removal of surrounded own stones after removal of opponent's stones
ko: PSK = positional super ko (no repetition of whole board position), SSK = situational super ko (no repetition of whole board position if the same player's turn), Ing = fighting and disturbing ko depending on settlement of life and death, void = basic ko rule + no result for whole board repetition in complex kos (formally for CHN it is PSK + no result for exceptional kos; the effect is roughly the same)
definitions, ko, ko classification

END	Simple	AGA	Ing	CHN	JAP	IGS
scoring	area	area	area	area	territory	territory
counting	not set	not set	fill-in	Chinese	Japanese	point
additional phases	none	agree	agree	agree	Japanese	agree
final pass number	2	2 or 3	4	2	2	3
pass stones	no	yes	no	no	no	no
dame valuable	yes	yes	yes	yes	no	no
score empty points in seki	yes	yes	yes	yes	no	yes

scoring: which points determine the win; area = colored points + empty points surrounded by the color; territory = empty points surrounded by a color + opponent's prisoners; for AGA area and territory scores equal; in general area and territory scores are close since for each prisoner a stone misses on the board
counting: if not set, point-by-point counting can be used; point = point-by-point counting (scanning the board or using a finger; it suffices to count one color); Chinese = Chinese half counting (like point-by-point half counting, but with much rearrangement of stones); fill-in = each color uses an equal number of stones that are all filled in so that only one board point remains empty; Japanese = put prisoners on board and rearrange
additional phases: none = alternation is immediately followed by two game ending passes, all removals must take place before in alternation; agree = alternation is followed by stopping passes, an agreement phase (that can lead to resumption of alternation), and ending passes, during agreement the players verbally agree about removals; Japanese = alternation is followed by stopping passes, a confirmation phase (putting remaining dame and defensive moves inside territory on board), ending passes, and removals (done accordingly to complex rules using hypothetical play)
final pass number: the exact reasons of various settings for numbers of passes are often lengthy and differ considerably
pass stones: for each pass the opponent receives a stone; this enables equality of area and territory scoring
dame valuable: dame are scored and thus should be played alternately
score empty points in seki: Japanese rules traditionally exclude sekis from scores
game end, game end classification, examples