Kami Kaze is not the only one of late who has been asking about the rules used in Korea. At the IGF rules committee last year the old Korean rules were described. Some articles were also published about them in a Chinese magazine "Wei Qi" in July and August this year. Nowadays in Korea they use the Japanese rules.
The earliest known references date back to 475 AD. They used to start with 9 black and 8 white stones on the star points and intermediate points on the fourth line. The method of counting is different from both Japanese and Chinese rules. They count territory minus prisoners but territory is increased by removing some live stones which are not necessary to delimit territory. In diagram 1 the marked stones can be removed. The stone on the 4-5 point cannot be removed as that would leave a stone in atari.
Two strategic differences arise from the counting.
- 1. Simple kos can be of different values. In diagram 2 the ko at ‘a’ has a value of 5 points. If white connects it the marked white stones can be removed gaining 4 points. If black captures and connects the ko the marked black stone can be removed and black gains a point. This makes a total difference of 5 points for this ko.
- 2. "Neutral" points may or may not have some value. In diagram 3 the point marked ‘a’ is of value to both players whereas the point ‘b’ has no value.
The difference in the count using this method from that of either the Japanese or Chinese methods is quite large. It was probably necessary to abandon these rules to make international play easier.