Nakade

Nakade is a Japanese go term that literally means "inside move" or "move inside". It is also used in English. It represents a concept crucial to life and death, basic to even beginning players. It refers to a play inside an opponent's large eye that prevents the opponent from making two eyes there. It can also refer to stones inside an eye that prevent it from becoming two eyes.

See killable eyeshapes.

Basics

Nakade basics  

This is a basic shape where White has one large internal space, a "nakade" shape.

Three points.  

Black can kill by playing the nakade at . White can live by playing at the same point. A 30-kyu player needs to understand these basics of life and death. If White plays on either of the remaining internal points, he puts himself in atari and can be captured on the next move. If White does not play, Black can play on one of the empty points, thereby putting White into atari. If White then captures, Black plays again at one of the remaining two empty points, putting White into atari. White can capture again, but that leaves him with only one liberty and subject to immediate capture. See almost fill.

There are a fixed number of shapes which are subject to being killed, or living, in this fashion, and are called "nakade". They are typically designated by the number of empty points in the shape, called "n-moku nakade", and include:

• straight three--the shape shown above
• bent three
• pyramid four. Compare with bent four and straight four which are alive.
• bulky five and crossed five
• rabbity six
• butterfly seven
• two by three corner. Depends on outside liberty number (must be 0)

These shapes are shown below.

Straight Three  

Bent Three  

Pyramid Four  

Bulky Five  

Crossed Five  

Rabbity Six  

n-moku nakade

The form "n-moku nakade" specifies the number of points ("n") in the large internal space. "n" can be ni (2), san (3), yon (4), go (5), roku (6), or nana (7).

In the context of a capturing race, however, "nakade" can also be used to describe an internal space of "n" points, implying how many moves will be needed to fill it (and win the capturing race). Since a two-point eye is always dead, "ni-moku nakade" would only be used in the capturing race context.

Background

The Chinese word diǎn 点 means point, spot, drop (of liquid), speck, dot stroke (in writing Chinese characters), decimal point, o'clock (since the colon separator in times consists of two dots), etc.; in a Go context it almost always means point/place/location. The character yǎn 眼 means eye. Together, diǎn yǎn in ordinary Chinese can mean eye drops or even just eyes, but the Go meaning is eye-point, i.e. the critical point to make eyes.

The same character was often used in old Japanese texts and glossed as nakade, but sometimes also rendered as oki (placement). Like many Chinese terms, the nuance is better understood by viewing the term as coming from martial arts rather than the ordinary language. In Chinese sword-play, a dian is a stroke where you go slightly up and over the opponent's sword, arm, leg, etc to poke into a weak point (slightly) downwards. In go, it is as if you are approaching the group surrounding the space with your sword, you tip the point as you reach the wall, pass over it and stab downwards.

The reading "nakate" is also encountered.

Note: The material that follows till the end of this page is copied from the previous version and may require WME.

More on nakade

Unsettled eyeshapes are those eyeshapes where a killing nakade is possible.
Basic living eye shapes are those where a killing nakade (in one move) is not possible.
Dead eyeshapes are those where a nakade is not needed to kill: the group is already dead.

Be aware however that these basic shapes ignore two major effects:

• Eye shapes in the corner or on the side: see rectangular six in the corner and bent four in the corner.
• The presence of cutting points and shortage of liberties: see nakade example 1 and nakade example 2.

For several possible reasons, the eye shape may contain more enemy stones. Any eye shape which is filled with stones so that almost filling it with a killing shape is inevitable, is dead. These patterns are listed at killable eyeshapes.

A combination of both circumstances can be found at biggest known eye space for which there is a nakade.

See also

• Nakade example 3
• Nakade liberties
• Almost fill
• Oshitsubushi (a way to counter nakade)
• Killable eye shapes
• /Discussion