Vinceuji: What about starting with b14 ?
[current position] + B14B13C15
At worst it comes back to a correct sequence but with less choices for opponent. (I’m under impression it 100% kills but may miss some sequences)
guile: It doesnt kill as your opponent will wisely (or not ^^) retreat to live by discarding some stones...
... as in the second solution. But it seems to me that you are right : it brings us back to this same 2nd acceptable sequence.
This path has not been added (maybe) because stronger player actually recognize a way to kill.
Hunt for the killing Ko my friend (so hard but so nice) !
sinan: The answer is wrong. The marked solution doesn't kill actually. It only captures some stones. However, the move at B15 results in Ko (Gote or Sente depending on the answer). The actual solution should be B15-C15-A12! Now we can kill...
posetcay: Added ko solution, but also kept the previous one. It is hard to argue that one is better than the other, since it depends on the rest of the board, so I kept both.
It doesnt kill as your opponent will wisely (or not ^^) retreat to live by discarding some stones... ... as in the second solution. But it seems to me that you are right : it brings us back to this same 2nd acceptable sequence. This path has not been added (maybe) because stronger player actually recognize a way to kill. Hunt for the killing Ko my friend (so hard but so nice) !