Small avalanche

  Difficulty: Expert   Keywords: Joseki, Go term

Chinese: 小雪崩 (xiao3 xue3 beng1)
Japanese: 小ナダレ (konadare)
Korean: -

[Diagram]

Small avalanche

W4 and W6 is the avalanche joseki. If Black plays B7 here, then we get the small avalanche.

[Diagram]

Small avalanche

Subsequently, W1 to B4 are all forced. Notice that B4 threatens to capture the two key white stones in a ladder at x.

The typical response for W5 is at a, possibly leading to the canonical joseki. However, if the ladder is favourable for White, then W5 can also be played at b.


Table of contents

The canonical joseki and its variations

[Diagram]

Canonical joseki

This is the canonical joseki for the small avalanche, most often seen in the literature. B2 is the most usual answer, but there are other variations. After W3, the black+circle stones cannot be saved, so Black goes for the upper side instead. This canonical joseki is also the simplest small avalanche joseki because both groups are settled.

White has some influence along the left side as well as points on the corner, but Black's thickness on the right is truly impressive, after having captured two stones. Also note that Black's influence is along the upper side, which is typically more important than the left side when White chooses to play the avalanche.

For beginners, it is worth noting that W7 cannot capture the B4 stone by playing at white+circle, because then Black will capture all the White stones in a connect-and-die with a move at W7.

[Diagram]

White tenuki

There are cases where White omits W9 in the previous diagram, but they are rare. A likely continuation when Black pulls out with B1 is shown here. In this diagram Black has played on both sides - the difference from the normal joseki is large.

[Diagram]

Attaching with B4

B4 can also attach as shown here; Kogo's give this variation as a joseki. Note that B8 is not played at a, so as to allow cutting at b later.

[Diagram]

Attaching with B4

Note that W5 must not atari here, because after B6 extends, W7 can only capture the two stones. After B8 and B10, the result is too good for Black - Black is too thick.

If W7 connects at B8, then B8 plays at a and takes the whole corner.


Fighting variations

[Diagram]

Fighting variation

B2 at the vital point is a strong move which provokes a fight. Up to W9 there is little room for variation.

[Diagram]

Fighting variation

The joseki continues with these moves, but the fight is just beginning. The Black group in the center and the White one on the top will have to fight it out afterwards.

White may choose to give atari at a before playing W2. This will make White b sente, but the value of White c is diminished. Black for his sake, might play d or e instead of B3.

[Diagram]

Another fighting variation

B2 is yet another possibility. After B10, a, b, and c are all possible continuations for White, and the fight spreads into the center.


Ladder favourable for White

[Diagram]

Ladder favourable for White

If the ladder towards the lower right corner favours White, then W1 can extend here. Then the sequence here is most common. With B8, Black has saved his corner, but still must face the center fight. The continuations are the same as above, but W1 makes better shape than White a.

B10 may be played at b or c. With B10, White will get better endgame benefit if White gets to play at d. With B10 at b or c, White can get some endgame benefit on the left edge.

[Diagram]

Ladder

The ladder referred to in the commentary to the previous diagram is shown here. White should play this W1 only if the ladder of B8 does not work.

Charles Matthews: This absolute statement needs to be qualified by a sacrifice variation from Korea. See Jungsuk in Our Time.

[Diagram]

Too submissive

If the ladder does work for Black, the only way for White to avoid an immediate collapse is to extend at W3. However, this is too submissive. B4 now is enough to capture the corner, and Black's advantage is immediately apparent.

[Diagram]

Expensive wall

On the other hand, if the ladder favors White, B2 is uncommon. The only joseki for this situation is this one.

[Diagram]

Expensive wall

Eventually, Black makes a wall towards the top but gives both the left side and much of the corner to White. It was developed in Korea in the late 1980s.


Trick play

[Diagram]

Trick play

There is also a variation where Black plays at B4 instead of a. This is a trick play, but the refutation can be difficult to find. See small avalanche - trick play for more.


Mistakes

[Diagram]

Mistake

It would be a mistake to cut at W1. Black simply connects with W2, and White's position is in pieces.

[Diagram]

Mistake

unkx80: Please explain why B4 or a is a mistake that results in considerable White thickness.

[Diagram]

Mistake

In the joseki, W1 should be played at a or b. If W1 cuts directly, then B2 captures the two key stones, and typically this means "game over".


See also:


This is a copy of the living page "Small avalanche" at Sensei's Library.
(OC) 2014 the Authors, published under the OpenContent License V1.0.
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