I am a big fan of Chinese rules. I have heard that New Zealand rules are pretty darn close to Chinese rules. I tried looking up the actual New Zealand rules the other day, but the way they are worded, like other rulesets, is a bit hard to follow. I was hoping we could discuss how the two rulesets differ. Anyone out there that would like to rattle off some love for New Zealand ?
To those who want the quick answer, without the conversations that followed below, here is a complete list of the differences between Chinese and New Zealand rule sets:
Komi: It is 7, which means that draws are possible.
Suicide: Chinese doesn’t allow it. But one aspect that distinguishes New Zealand rules from several other rulesets is the lack of an additional rule that forbids suicide. In other words, you can fill the last liberty of a group of your own stones stones, resulting in self capture. This can be relevant. For example, a player can suicide two crushed stones to make a three-space, which must be responded to, because it creates an extra ko threat. For a comprehensive discussion of these differences, see Suicidal Tendencies and Positions With A Good Suicide.
Game Position Repetition: Chinese uses Positional Superko, New Zealand uses Situational Superko, and Japanese doesn’t use Superko at all. To understand the difference check out: Superko, Positional Superko, Situational Superko, and the following example:
Game Conclusion: Chinese games are concluded when two passes are made in a row. New Zealand games end with a verbal agreement by both players. The game is finished when both players agree that there are no more worthwhile moves. ‘Dead’ stones may then be removed from the board by mutual agreement. If they cannot agree which stones are dead they must play on. If they cannot then agree who shall move next, all stones stay on the board (are alive) and are counted.
Note: It is believed that this can be exploited under the right circumstances. Read more about that here: Possible Exploit/Loophole in the NZ agreement phase handling. However, this potential loophole is not possible in the OGS implementation of New Zealand rules, thanks to the stone agreement phase.
Handicap Games: Under Chinese rules, Black gives White compensation for handicap stones, so that the area which they occupy is not counted. Where N stones are given, N/2 is added to White’s score and N/2 is subtracted from Black’s score. Under New Zealand rules, no such compensation is given. The effect of this is that an N stone handicap is N points larger under NZ rules, than under Chinese rules. Under NZ, White passes the first N-1 moves, where N is the size of the handicap. And Komi is not to be used.
Note: It is worth mentioning, that there is no mention of handicap in the official Chinese rules. However, this is how Handicap is most commonly implemented when utilized.