[Welcome to Sensei's Library!]

RecentChanges
StartingPoints
About


Paths
LifeAndDeath

Referenced by
GoTerms
SixDieButEightLive
FourIsFiveAndFive...
BasicLifeShapes
ANoviceTriesToWri...
BulkyFive
TwoEyes
KanazawaSolutionTwo
AlmostFill
Placement

 

Nakade
  Difficulty: Beginner   Keywords: Shape, Life & Death, Go term

A nakade is a large unsettled eye shape, possibly resulting from a capture, that can be reduced by skillful play to a single eye.

"Nakade" literally means an inside play. The play inside the eyeshape is the nakade. -- BillSpight

It is especially useful to identify positions where one move can decide whether there are one or more eyes in a certain space.



Basic nakade


[Diagram]
Diag.: Two points

A two-point nakade is insufficient to live. In this position, white is dead.


[Diagram]
Diag.: Three points

A three-point nakade depends on sente. If black plays at 1, white is dead. If white plays there, she lives.


[Diagram]
Diag.: Four in a row and farmer's hat

Four spaces in a row, whether straight, bent once (like an 'L') or twice (like a 'Z'), is enough to live. If black plays 1, white plays 2, and vice versa. (1 and 2 in the diagram are miai.)

The shape on the right is known as the farmer's hat. Its life depends on sente. If white plays at 'a' she has three eyes, if black plays there white is reduced to a single eye and dies.


[Diagram]
Diag.: Block of 4

A block of 4 on the other hand, is dead as it stands. Even if white plays first, black can kill her. It is not unsettled, and therefore it is not a nakade shape.


[Diagram]
Diag.: cross

In this cross of size 5, black can kill white by playing at 1.


[Diagram]
Diag.: bulky five

This shape, nicknamed the 'bulky five' in English (gomoku nakade in Japanese) is killed by the placement at 1. The remaining shapes of five spaces are all alive even if black plays first.


[Diagram]
Diag.: rabbity six

Of the six-point nakades, only this one can be killed. It is known as the 'rabitty six' (it vaguely reminds one of a rabbit's head, the ears are at the top left) or 'nutcracker'. It is also known as the 'flower six' because the japanese term for this shape is 'hana-roku'


[Diagram]
Diag.: seven lives

All eye shapes of seven points are alive. This shape is one that seems most likely to be killed, but after black 5 the position is seki (actually, white could also play tenuki after black 1 - the situation is then already seki as it stands). So this shape is not a proper nakade.



Other types of nakade


[Diagram]
Diag.: Cutting points

Although the eye shapes that have not been discussed here are alive, there are still two situations in which that does not need to be the case. The first is the presence of (two or more) cutting points in the white shape. Normally, the 3x2 block is alive (3 and A are miai), but in this position, because of the two marked stones, black 1 is an atari, forcing white to answer at 2, after which black 3 kills the group.


[Diagram]
Diag.: The corner

The second possibility where problems can occur is in the corner. Because of the presence of the corner, white again dies despite her big 3x2 eye shape.



Biggest known nakade


[Diagram]
Diag.: A problem from IgoHatsuyoron (Black to play)

The bigger the eye shape gets, the less likely it is that all surrounding stones can be killed. There is no known nakade bigger than 16 points.



See also AlmostFill



Authors:

  • Andre Engels
  • jvt
  • (add your name if you make a significant contribution to this page)


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