Sadaharu: @posetcay right when the opponent plays Q1 to attack, N5 should work too. Currently it's marked as wrong
posetcay: Sorry I really don't understand which sequence you are talking about, can you link SGF or write move by move from start? There some variations where playing Q4 too early is marked as wrong because it leads to ko, maybe you are talking about those?
jhubert: Atari is not good as on N5, you can play on S1 :( but may be you can play also P5 and N5 but it is less stylish
posetcay: Atari is as good as playing N5 directly if you play it with right timing (after exchanging R1-N1), otherwise opponent can play N1 at S1, was that what you meant? I added N5 directly as an option by the way.
Sadaharu: Many interchangeable sequences missing.
W can just play at N5 instead of atari at Q4 too.
posetcay: I missed that it was possible to N5 directly without atari, but can you provide other missing sequences? I omitted some of the variations that work but were suboptimal or unintuitive like Q4-R6-P5-O5-N5 or D10 at D11 because the solution tree was too long and I had to shorten it.
Sorry I really don't understand which sequence you are talking about, can you link SGF or write move by move from start? There some variations where playing Q4 too early is marked as wrong because it leads to ko, maybe you are talking about those?