Of human blindness and how ridiculously bad the Magic Sword joseki is.
Everybody should know by now that, in the Magic Sword joseki, White can just bluntly capture Black’s stone in the corner and get a good result.
This can lead to one of the following shapes, give or take some minor exchanges:
The exchanges before/after Black’s cut aren’t clearly profitable for either side, so we’ll regard all three shapes as equal. Pros and cons.
I realised that we’ve always had a joseki that is very comparable to the second shape:
This is a more or less inevitable sequence after Black 1. It’s rarely played because White gets such a big territory in what used to be Black’s corner.
The following tewari shows that shape #2 is even better for White than this joseki.
The initial shape is super good for White and the following exchanges downgrade the result to something that is still somewhat satisfactory for White:
White takes an inexplicable gote to defend inside. It’s rather slow to defend against Black A and B at this point, though it also enables White C next. The latter, however, immediately becomes irrelevant because Black gets to cut at 4 in sente, and against 6, White again answer strangely submissively.
Losing sente is especially crucial because both would like to get a move outside, either to build on or restrict the influenze. This shows just how bad the initial shape was for Black.
No idea how this has been overlooked all these years… 🙂