[Welcome to Sensei's Library!]

RecentChanges
StartingPoints
About


Paths
Shape

Referenced by
GoTerms
ThreeThreePointIn...
APonnukiIsWorthTh...
PlayAwayFromThick...
EnglishGoTerms
Atsui
TsukeNobiClamp
ComplaintAboutShape
AboutInfluence
SmallNadare

 

Thickness
  Difficulty: Advanced   Keywords: Ko

Thickness

This subject has been WikiMasterEdit-ed and re-referenced. The discussion can be found at OldAtsui. Material from OldThickness has been included. --DieterVerhofstadt

Thickness = Strength + Influence

Atsumi is a Go-term meaning "the influence of strong stones". We translate it into English with the word thickness. In order to be thick, a group of stones must be strong and it must have influence in a certain direction.

Thickness, strength and influence are often used as synonyms of eachother, hence the discussion mentioned above.

Strength

A strong group is a group with no defects: the stones belonging to the group are connected and have sufficient potential for eyespace. Strength is the local property of a group of stones to stand on its own, the ultimate strength being the group living regardless of what the opponent plays in the neighbourhood.

Influence

Each stone has a certain influence on the board. Captured stones have an influence close to zero. Surrounded stones that make a live group, influence only the surrounding group. Stones that are in open space have an influence on that open space and the stones bordering that open space. Influence is a long range effect. For example: a ladder breaker? changes the balance in in the opposite corner.

  • The stronger a group, the greater its influence on a neighbouring area.
  • The more open the neighbouring area, the greater the group's influence.
  • The weaker the other groups neighbouring that area, the larger the group's influence.

In Go, maintaining the balance of territory and thickness is very important.

Examples of thickness


[Diagram]
Diag.: Thickness arising from a sansan invasion

Black has the hoshi stone and the marked stone in place. White approaches with the keima kakari at 1. Black answers with the pincer at 2. White jumps into the corner with 3, and up to 8 the sequence is very common. White has thus taken territory but Black has created a group, consisting of a wall? 4-6-hoshi, virtually connected to 2 and 8. The marked stone provides for sufficient space to make eyes for the group. The black configuration is strong and influences the center and the right side.


If the marked stone in the previous diagram is not in place, Black might block the ThreeThreePointInvasion from the other side, in order to create thickness.


[Diagram]
Diag.: Thickness arising from a sansan invasion (2)

Again, Black builds a wall?. The marked stone is now closer to the wall, but because a white stone is already in the area, this makes perfect sense. This configuration is again regarded as strong, and influences the center and the lower side.




[Diagram]
Diag.: Thickness arising from a sansan invasion (3)

This is what happens when white immediately makes a ThreeThreePointInvasion. White 7 creates a weakness..


[Diagram]
Diag.:

The White stone is captured in a geta, but some aji remains. White can not run out at A immediately, however. Black is thick.


[Diagram]
Diag.: If white runs out

Black 2 sets up a geta. White 9 is at the marked stone.



Further reading:

Influence
PlayAwayFromThickness
KikashiAndInfluence



Authors:

FCS
HolIgor
MortenPahle
AlainWettach
DieterVerhofstadt



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