WJTetley: May I know why the move D.1 isn't considered a good/valid move? I used the "Review" button to check and as far as I can tell black has no good counter to the move that won't end with black being captured.
Igor Popov: Hello, black can still kill with: B P1, W P2, B Q1 There is no way white can save the group. Even if white can capture the stones at Q1P1O1 then black can play at P1 and white will have just one eye without any chance to create another.
May I know why the move D.1 isn't considered a good/valid move? I used the "Review" button to check and as far as I can tell black has no good counter to the move that won't end with black being captured.