Chinese Ko
Elwyn Berlekamp and Yonghoan Kim use the expression Chinese Ko in their paper Where Is the “Thousand-Dollar Ko”?,[1] apparently to refer to a ko that can only be worth fighting when Chinese (area) scoring is in force.
The ko in question looks similar to this, where all stones except the marked stones are independently alive:
With Japanese (territory) scoring, there are no points to be gained here: we expect Black to connect at k and White to connect at w or b. With area scoring, however, it turns out that it can be worth fighting this ko!
With area scoring, if Black is not komonstrous, then
is sente, after which
is a normal dame. (With Japanese scoring,
is a tiny ko threat and
is the reply.)
With area scoring, if
Black has "sufficiently many kothreats that" Black "can avoid filling" k "until after all dame are filled and White is forced to either pass or fill in a point of" White's "own territory while" k "remains empty and surrounded by Black", then
is sente, after which Black gets k as if it was a one-sided dame for Black.
(The quotes are from page 216 of [1].)
Although the initial shape might be different, once the ko appears the situation is identical to that treated in DameKoThreats
References
[1] Where Is the “Thousand-Dollar Ko”?, Elwyn Berlekamp and Yonghoan Kim, Games of No Chance, MSRI Publications?, Volume 29, 1996, http://library.msri.org/books/Book29/files/kim.pdf .
- This paper analyses four problems based on a minor variants of a position that appeared on the inside cover of Go World, issue 70. In each case, one assumes that the winner collects a prize of $1,000. If he wins by more than one point, he can keep the entire amount, but if he wins by only one point, he is required to pay the loser $1 per move. The problems require one to say how long the will game last in each case.