# What are the difference between Chinese and Japanese rules in Go?

What are the differences? And do these differences influence strategy?

• In france and america, the AGA rule is very nice: it makes every situation to be played to be resolved (where Japanese rules have many special cases treated according to the rule). the AGA/french/? rules also allow one to use both Japanese or Chinese counting, therefore quite nice to use (as both players play the same amount of stones, the counting will be equivalent in "almost every cases") – Olivier Dulac Nov 26 '13 at 20:00
• I like to teach Go by presenting only the Chinese rules (It focus on the main goal: occupy territory! Everything is played out. Prisonners are not important "per se" [and it's nice to show that you can just hand them over to the opponent]. So the learner knows she/he has to focus on occupying territory instead of capturing stones. Do NOT confuse them with 2 set of rules. Later, I do use Japanese COUNTING, as it's fast: put prisonners back into opponent's territory, arrange empty areas in multiple of 10 [5x2, 10xn, 3x4-minus2stones] so that it's both easy to count AND to re-count if unsure. – Olivier Dulac Nov 26 '13 at 20:02

In most games (as already noted) the two rulesets produce the same strategy and outcome.

Differences between the current Japanese and Chinese rules:

• Japanese counts enclosed territory (of groups able to form two eyes) minus prisoners (stones that the opponent was able to capture). Chinese counts all area: every intersection is attributed to whichever side’s stones enclose or occupy it; unfillable dame (i.e. intersections left vacant between opposing groups of stones, after captures are removed from the board) are split 50/50.

• Chinese report on how far either player is from a draw (of 19×19÷2 points each), whereas Japanese report on how far apart the two player’s scores are (a margin which should differ by a factor of two).

• Groups of stones that live in seki (e.g. that border unfillable dame) sometimes still enclose some space (e.g. one eye). This is not counted as territory by Japanese, but does count in Chinese.

• Super-ko (i.e. cycles which exactly recreate a previous board position) nullifies the game for Japanese; in Chinese it is in principle an illegal move but can also be judged a draw, void, restart, etc.

• After the game concludes, life or death (i.e. assumed captures) is resolved in Japanese by virtual play, under a modified rule that retaking a ko requires an extra move. (This seems intended as an alternative to super-ko for circumventing unremovable ko threats.)

• As compensation for the first move advantage, Japanese gives white 6.5 points (komi) and Chinese transfers 3¾ from black to white (i.e. 7.5 komi).

• Japanese rules are understood to have more ambiguity and/or inconsistency, related to the complexity of life and death.

Consequences:

Entirely procedural:

• Only Japanese requires keeping track of captured stones (prisoners). In longer games this can use more playing stones.

Semi-procedural:

• In Japanese, the game can finish before dame are filled.
• In Japanese, captures inside of seki groups are played out (because prisoners are counted despite there being no territory counted).

Affecting beginners:

• Unnecessary defensive moves are more costly in Japanese rules (subtracting a point in addition to the wasted turn itself).
• Assumed captures are left on the board in Japanese rules, whereas under Chinese rules any "life or death" puzzles can ultimately be played out (simplifying the board) without loss of points.

Affecting high-level play:

• If the game runs out of dame and meaningful moves after an odd number of turns, then white gets an extra point in Japanese as compared to Chinese rules. (Some other rulesets negate this difference between territory and area counting, e.g. by insisting both sides make an equal number of moves.)
• During the opening, aggressiveness/defensiveness relates to the amount of komi.
• The urgency/worth of resolving the status of an unsettled (but potentially seki) group can be slightly different (since some seki have different value between Japanese and Chinese rules).

Note that in close games between players who are strong enough to accurately predict score, a small difference in points may cause a completely different choice of strategy for a particular board position.

From Wikipedia:

Although there are some minor differences between rule sets used in different countries, most notably in Chinese and Japanese scoring rules, these differences do not seriously affect the tactics and strategy of the game.

There are two basic scoring systems used to determine the winner at the end of a game; they almost always give the same result. Territory scoring counts the number of empty points your stones surround, together with the number of stones you captured. While it originated in China, today it is commonly associated with Japan and Korea. Area scoring counts the number of points your stones occupy and surround. It is associated with contemporary Chinese play and was probably established there during the Ming Dynasty in the 15th or 16th century.