Noseki 3

Path: <= Noseki =>
dia. "Noseki" no.3  

Black makes the rare combination of attach B2 and cut B4. B8 captures W3 in a ladder. The fact that Black has made a ponnuki seems to be outweighed by the damage done to black+circle. Still, there is a lot of space below the White string, where Black can live.

This is a variation I have encountered in large handicap play. It is not so easy to win against a bunch of ponnukis. --Dieter

tderz: attach B2 and cut B4 are not rare, but often used to overconcentrate white on the top. Cf. with the Joseki (iii) starting below.
The question is. in how much did white react adequaete with W5? A much more often used move is W5=a or =b. (the frequency of a move is not so important)

W9 changed  

tderz: Was W9 necessary, or could it better have been at c?
(better grip on corner stone? sente? gote? honte? for B? for W?)
If black tenukis with B10, nice ladder aji remains.

Bill: Shouldn't B10 be at c?

tderz: This option {at B8} was already given initially (by Bill) below as Joseki (i)-(ii). Bill, further below I support your view that B10 used for blocking is nice, simple and confines the group. I also prefer the B10 at c.Furthermore, most of the variations which spring to mind are somewhat forced, Black can fully use White's liberty problems. The (joseki) sequences end in a known way. This sounds like a pleonasm but I want to emphasize that White came out in Joseki (iv) and (4), thus is not confined. Black would know much less what such a position is worth.

Bill: Actually, I was the one who added the Joseki (i) - (ii) diagrams. As for Joseki (iv) and (4), isn't the Turn diagram better for White?

tderz: They - turn, (iv) and (4) - all then share the white gote ending. The turn-variant is one line higher, does it also make her more vulnerable? I have no clue.

attempt for a summary  

tderz: We have sofar the proposal by Dieter of

  • playing first white+square, then the turn as honte-improvement white+circle by Bill to get hold of black+square (to cope with Aji-2)
  • or my transposition of playing first W9 (=black+circle here) and then white+square (to cope with Aji-1 below by Dieter) or
    • another move, e.g. white a against aji-1.

  • In Joseki (iv) White jumps as afr as b and the top black side is open at its skirt at s.
  • In Joseki (4) White jumps only to j, but the black skirt is not open.

If there was a white choice betwee (iv) and (4), everyone would go for (iv). (There is no real choice 9iv vs. 4) on the board possible because Black went another way, nobi in (4) instead of crosscut in (iv). We only can compare here (now) the turn-variant vs. (iv). The differences are

  • turn: White on 4th line and tight (safe) +
    • if Black does not block on the outside (B8=W9 in noseki3 above), he cannot prevent this result.
  • iv: White on 3rd line, some extension (b) + black open skirt s and
    • Black could chose many other ways instead of end result (iv).

What do we prefer? I don't know.


another defense vs. aji-1

Bill: This diagram assumes black+circle instead of Ba.

Variations for W5 & B8

Joseki (i)  

Joseki (ii)  

White is cramped, but has Sente

Joseki (ii-1)  

tderz: W1 will more often be played like this, B2 and B6 fully exploit White liberty problems mentioned above.
White ends in sente, but the Black gote is a big B8.

Joseki (iii)  

tderz: W5 or b

  • i) W5 is very well covered here on Senseis already (see Attach Crosscut corner patterns), there are relevant diagrams. It comprises in the most often used variant two white kikashis (c & d), which must be played in the right order, before White captures the cutting stone B4. However, if it was black's aim to overconcentrate White (because there is already a nearby (top left), strong white position, then Black succeeded in a way (if Black plays everything correctly, he might then take less handicap stones).
  • ii) Especially b can lead to interesting variations if Black tries to resist strongly/stubbornly (if not reverting to i)).


Black transposition - Joseki (iv)  

tderz: Another transposition - only concerning the black stones (from a Chinese DingShi book)
I like the result better for White than "Noseki 3".

Bill: But White has taken the last play in this diagram.

Remark: I don't see any Black playing this in a handicap game. Which Black would like to have a ponnuki with white totaly safe and out on both sides?
It might be even in even games, but simple blocking (Joseki(i)) seems to have much more synergy with the other handicap stones.

another Joseki (4) with similar result  

tderz: I try a tewari analysis here.
This is another Joseki (4) with a similar result, i.e. the black stone formation is identical.
It ends in Gote for White (different from Noseki !).

The point I want to convey is, that I like White's position here much more than in the original diagram "Noseki no.3".
This is, because white is one line lower, but controls that area much more safely.
Hence the question is, "Is the loss of tempo (Noseki ends in W-sente, both transpositions end in B-sente) worth the positional difference in a (handicap) game"? Difficult to judge. But this are the considerations to be made.

Hence, if the black position is the same (by transposition), then, where did White deviate (to her disadvantage?) in Noseki3?

Bill: By playing elsewhere.

B8 "deviates" from the obvious blocking (cf. Joseki (i)+(ii); nice influence, as Black I would usually go for it - keeps the game simple) in dia. Noseki3, hence up to W7 everything looks normal.
So I come to the conclusion, that W9 (in dia. Noseki3) makes it odd-looking.

Joseki (5)  

above derives from this sequence. B4 stretches first, then cuts at a.

Aji 1  

Even if White plays hane at W9 in the diagram by tderz, there is a lot of aji.

Aji 2  

The potential here is large too. So probably White has to take gote in both.

Bill: I think so. Shouldn't White make the turn in the next diagram?

Alex Weldon: I agree. That turn is honte and also quite large in terms of corner territory and influence on the lower side. Definitely worth taking gote for, but precisely the sort of move amateurs are likely to overlook because they believe it to be slow. Kageyama praises a similar move at one point in his Lessons in the Fundamentals of Go.


See Attach Crosscut corner patterns

Path: <= Noseki =>
Noseki 3 last edited by MrTenuki on December 24, 2006 - 19:53
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