is required, really (at a for mad variations including seki).
Assuming White was set on sacrificing the stones, this would do, I think. White has a useful kikashi still at b. If you look at it, White at c is also a threat here.
This kind of 'plaster the outside' variation is usually assessed quite favourably for the side with influence, despite cutting points.
So, is this really the one-way street it appears?
Bill: Instead of in diagram (iii), I think B b is OK. White may play at c with sente. I also think that White needs another play here. Maybe the capture at d.
Charles I did assume this was unplayable for Black. Do I have this right?
Bill: I was thinking more along these lines, if White played right away. Making seki, if it is even possible, is a large yose. The stones are not necessarily alive. weakens them. While instead captures the White stones, it gives White kikashi with , strengthening those () stones. If White plays kikashi on the left instead of , Black still captures White's stones and is better than . And if White neither plays such a kikashi nor immediately, Black may get stronger on the left side, making ineffective anyway.
On an empty board, I think that - W a, is better than this diagram for White, and - , B b is even better for White. Which would have been better in the game really depends on the surroundings, I think.
Charles You're right - the seki may be eye-catching, but White wouldn't have time to play it yet: and holding together the outside is going to be 'interesting'. Black has not profited much yet, though. One of the more bizarre variations on SL.
And the unkx80 variation on Shape Problem 6/Discussion starts not only to look more 'sensible', but possibly objectively better sometimes? Actually this gets off my radar as far as judgement in the abstract goes. The joseki books, or the older ones anyway, pronounce on such things.
TDerz: It is interesting to see why another appealing move doesn't work either: My first thought was this kosumi-, atekomi or kosumitsuke-tesuji? combination. White must defend at a and wants to block at b. However, independent of ladders in the direction of c...