Geoff Kaniuk's referee exercises

[yebellz]

@gennan

The only problem arises when there are unremoveable ko threats in the resumption phase (like some small seki somewhere on the board). In that case, bent-4-in-the-corner might live in some cases (similar to AGA/Chinese rules).

Yes, this is precisely the kind of situation that can cause issues. However, that’s not the only problematic pattern.

@le_4TC

Here’s a fun position, not quite bent four, but pretty closely related:

---

@gennan

But when both players play correctly/perfectly in such a resumption, the Japanese score at the moment of the first 2 passes would be preserved by the pass stones after resumption. So it’s not area scoring.

However, it’s not really Japanese scoring since life and death status in various edge cases are changed. From the perspective of the adherents for formal application of the Japanese rules, those weird edge cases are viewed as key features, rather than bugs that should be removed.

@gennan

in practice it would be a very close approximation of Japanese rules

KataGo uses an even closer approximation of the Japanese rules. See https://lightvector.github.io/KataGo/rules.html (and click on “Japanese-like rules”). However, it introduces its own intricacies that could be tricky to understand.