Richard Malcolm: Just end the problem when you get to the ko. You don't even need to be efficient with threats to win.
So annoying to lose because the problem is missing winning variations.
TwT: Dear Richard, thank you a lot for being annoyed without telling us why. Additionally, congratulatinos for best comment regarding: I do not know nothing, but it is your fault.
StephaneLamy: There are too many uncovered variations in this problem.
After H8C9D9H9, any move among J5, J6 or J8 should be winning, but is marked incorrect.
I would suggest to give up completely on the line H8C9, who needs so many variations ?
In the other lines H8H9 or H8J8, many natural ko threats are still missing...
Sadaharu: H8C9D9H9 is not a winning variation. It's hard to add all the sequence for the ko threats. If there's any missing please let me know
StephaneLamy: After H8J8J6D1C2E9D9G9F9J5J4E9J5 it says incorrect, but the position is winning for black: either black gets J7, or win the ko at E9. In fact any threat instead of J5 (E3, B6...) should also be correct.
Sadaharu: Yes there are many variations to the sequence of the ko threats so it's hard to cover them all. I added a few
Richard Malcolm:
Dear Richard, thank you a lot for being annoyed without telling us why. Additionally, congratulatinos for best comment regarding: I do not know nothing, but it is your fault.