AGA Rules

AGA rules are designed to provide greater formalization of tournament play. Of the old traditional go rule systems, they are closest to Chinese rules, but have a number of features.

• Komi 7.5 points. In the Komi handicap, it is 0.5 points.
• Situational superco. The rule ko prohibits the repetition of a position on the board with the same turn of the move (repetition with a different turn of the move is allowed).
• Topological definition of the territory . The territory of the player is considered to be all empty points on the board, which are surrounded on all sides by live stones of his color. Points surrounded by lively stones of two colors are considered neutral and do not bring points to any of the players.
• To complete the game, it may take up to four passes. When players pass in a row, the game stops. If players agree on which of the remaining stones and groups on the board should be considered dead, these stones and groups are removed from the board and scoring begins. If no agreement is reached, the game continues from the same position until all disputed groups are withdrawn. If the players do not agree on the status of the groups, but four passes are made in a row (that is, the players pass successively twice in succession), the game ends and all the stones remaining on the board are considered alive.
• Pass fee. A player who, instead of his next move to the board passes, must give his opponent one of his stones. The opponent connects this stone to his won stones and takes into account when calculating points, if the calculation is based on territory and captured stones (see below).
• White always makes the last move. If, at the end of the game, Black was the last to pass, White must make another move (in the case of a pass, they, as in a normal pass, give Black one of their stones). Thus, the same number of moves is always made by both players.
• There are two ways to count points. By agreement of the players, either the Japanese method of scoring (according to territory and captive stones) or Chinese (according to territory and own living stones) can be used. If the players do not agree, the Japanese method is applied.

The two most unusual elements of the AGA rules — the pay for the pass and the requirement of White’s last move — are designed to guarantee the identity of the result when counting according to different rules and to enable safe play of the position. When choosing the Chinese method of counting, paid passes and an extra move (usually a pass) for White do not have any effect on the outcome of the game (since these rules only affect the number of stones captured, and points are counted according to the position on the board, excluding captives). The Japanese way of counting gives different results if the players go to their territory (for example, to remove disputed groups when they finish the game) and fill in neutral points with the last move of blacks (in this case, blacks get one point more by Chinese rules than by Japanese). The stones given by the players for passes compensate for this difference, thus guaranteeing the same points difference according to Japanese rules, although the absolute number of points scored by the players may differ for different calculation methods.

In general, the advantages of AGA rules include their formal accuracy, simplicity and complete certainty. Unlike traditional Japanese rules, in which only an experienced player can understand the most complex elements (for example, to correctly calculate the territory, you need to understand what an “eye”, “false eye”, “sack” is), all concepts and principles have a clear definition , which does not require understanding the tactics and strategy of the game. In particular, it should be noted:

• a topological definition of the territory that makes scoring simple and straightforward;
• superko rule, which formally determines the permissible and unacceptable moves in any position;
• determining the status of controversial groups by playing out, making special rules unnecessary about which groups should be considered alive and which are dead;
• Thanks to the pass fee, playing out in one’s territory does not reduce the player’s points, even if they are counted according to Japanese rules: if all neutral points are occupied and the player makes moves in his own territory in order to remove the opponent’s disputed group, then the opponent is forced to either return to his territory thereby keeping the difference of points unchanged, or pass, giving a stone at each pass and, thus, also maintaining the difference of points.

The disadvantages of AGA rules include:

• some artificial rules for White’s last pass and pay for the pass, which, in essence, are a kind of trick that guarantees the equality of the result of the game, calculated in different ways;
• In addition, the AGA rules have the same drawback as all the rules based on the Chinese method of calculating the result: they require filling in neutral points in the game time, which can cause time pressure problems (if one player fills in neutral points and the other passes, not having time make moves because of the small remaining time, the first one will get an advantage in points); in this system of rules, the problem is compounded by the fact that the player must not only say “pass”, but also give a stone to the enemy, which also takes time.

• AGA rules on the go association's website