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BQM78
    Keywords: Joseki, Question

Please can anybody advise on Black's best course of action when confronted with this irregular but tricky move?

[Diagram]
Where for Black 4?

I have investigated several lines and cannot find a clearly good answer.

Thanks - Tristan Jones

Charles Matthews Hamete alert! Lights flashing, alarms going off, whoowhoo from the sirens! Next B4 at a is the common sense play. So, how does White proceed after that to get a good result, in which W1/B2 isn't just a wasted exchange? White b, we look at Black c or d; I suppose the key line is White c if Black is unhappy with Black b, White e.


[Diagram]
Submissive?

That is, I take the query in this sense: after B2 here, does the BC/WC exchange make it look like Black has played submissively here?

Bill: In this position, is the comparison between WC and BC? Without WC, BC is normal, BS is not. So I think we should compare WC and BS, which is clearly bad for White.
That having been said, B2 does look too passive.

Ah, it seems that with your suggested move B4 that Black can transpose into a variation analogous to a good line that I found in Kogo:

[Diagram]
Transposition

Black chooses between a and b. At a is the correct move while b is falling for White's hamete:



Good for Black

[Diagram]



Black is tricked

[Diagram]



The actual joseki line is this, in which White has exchanged 3 for 4 already:

[Diagram]
Black attacks



It continues:

[Diagram]
Into the centre



And White is under attack, while Black is solid on the top.

Charles Well, OK, I see the difficulty.

[Diagram]
Go for the centre

One way that suggests itself is sealing off the centre with B1, accepting poor shape at B3 but making the point about White's shape with B5 in answer to W4. (On second thoughts I might not have the nerve for B5, playing at a.) This might work in strategic terms.

I suppose one should make the point that the initial attachment, to set up attach-extend (more likely attach-block to render White heavy), has to justify itself strategically against the diagonal attachment ordinary choice. I think the main reason for rejecting the diagonal attachment would be so as not to weaken BC. In this case it will become a stone backed up by influence.



Bill: My first thought was the outside hane, but it's difficult. E. g.,

[Diagram]
Two-step hane

After W10, B a.
Suzuki-Kitani's Small Joseki Dictionary shows B6 instead of B5, but that's without the BC stones. White threatens W b - B e, but Black's BC stones are working.


[Diagram]
Two-step hane, refutation

Oops! In the related sequence, Go Seigen, in Watch out for these plays! (Kono Te Goyoushin), shows the refutation to B5, namely, W6.



And what is wrong with the inner hane? E. g.,

[Diagram]
Inner hane

It's not so good on an empty board, because White is too good on the left side. But that is not so when Black has the BC stone.

Charles I can't answer that question, Bill. But as I assess the character of the player with White, she'd play ...

[Diagram]
Inner hane - variation

...W2 this way. So Black needs to be content with B3?

Bill: I like Black a (bo-tsugi) instead. :-)
Charles Possible ways to play W4 to make shape are at b and c now. Black a seems to be stronger against White c, Black at 3 as shown against White b? Interesting.[1]
Bill: Well, White has difficulties either way. :-)

Charles I don't think we have answered the initial question yet, quite. I do think the inner hane is good.


[Diagram]
Inner hane, solid connection

If B3 here, what will White play? It appears that in this case of the staircase, giving White nothing at all to work with by connecting might be apt.


[Diagram]
Continuation (i)

I don't believe White can connect solidly in return. The bulge B2 must be all Black could hope for round here.


[Diagram]
Continuation (ii)

After W1 I think we see up to W5 (perhaps B4 at W5 is also possible in some cases). Isn't Black content with B6? White can now exchange White a for Black b; but surely White is too heavy to launch a strong attack? White's play at c would have to be very telling, to call this a good result for White.



[Diagram]
Outside hane - Variation

Charles The added stone WS has marginally interfered with a normal 3-3 invasion sequence. White at a will be a nuisance later for Black. On the other hand White could try the 3-3 invasion at W1 after the attach-extend, anyway. In that case Black blocking at B2 would give this sequence, only with White knowing that White a has been answered at b (could be at c or d from the diagram position).

Therefore to argue this is poor for Black, you need to say that Black would want to block on the other side, at WC. That does look conventional.



[1] Charles Some results to consider.

[Diagram]
White's way to make shape (I)

If BS is played, W1 up to W5 tries to make the best of a bad job. White looks to make a and b miai, staying as light as possible (White is undeniably heavy after W3).

Bill: No thanks to WS and W1, either.
How about W c instead of W1?

[Diagram]
White's way to make shape (II)

If instead BS here, I think W1 is appropriate, to leave some aji at a. If B2 is at W3, White gets into the corner.


Bill: Oh, I would be thrilled to give White the corner. :-)

[Diagram]
Take my corner, please

Because of White's local ko threats, I assume that White can play W6, and take sente. Even so, comparing this with the 3-3 invasion, which also ends in White's sente, this is better for Black. White's corner is smaller, the exchange of WC and BC favors Black, and WS is not well placed.
As against that, White does have some aji on the left side.

Charles Given that, W4 at W6 could be considered here. But perhaps this feeling of constraint justifies Bill's botsugi idea.

Bill: Ooh, I like that play, Charles! :-)


[Diagram]
White's success

Assuming that Black cannot afford to make the ko, B2 is his only chance. B6 is tesuji.


[Diagram]
White's success (ii)

However, Black cannot win this fight. In this variation, Black loses his stones on the top side.

Is the bo-tsugi doomed? Maybe not.

[Diagram]
Bo-tsugi (2)

B1 aims at White's damezumari. Now B7 is safe. White has nothing better than to live with W10. B11 at a looks good enough.

However:


[Diagram]
Bo-tsugi (2a)

B4 - B6 works if the ladder does. But even then, W9 gives Black problems. I like White's chances. <sigh>


[Diagram]
White's success (iii)

So maybe this is better for Black (See White's success ii). This looks pretty even to me.



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(OC) 2003 the Authors, published under the OpenContent License V1.0.