Killable Eyeshapes Introductory

PageType: Path   Difficulty: Introductory   Keywords: Life & Death

For fully enclosed eyes outside of the corner there are a few critical eye shapes such that one the opponent has a play inside to prevent a second eye and possibly kill (depending on the surroundings). These shapes may all be derived from the Greek cross.

[Diagram]
Basic critical shape: Greek cross  

The basic critical shape is the Greek cross, and the critical point is the center (marked). Black plays there to live. If White plays there Black dies.

From this shape we derive smaller critical shapes: subshapes of the Greek cross that contain the central point and have at least 3 points.

[Diagram]
Critical subshape 1 (3 points)  
[Diagram]
Critical subshape 2 (3 points)  
[Diagram]
Critical subshape 3 (4 points)  

The critical point is still the center of the cross.

In addition, we derive two more critical shapes by adding a point to one L of the cross to make it a square. These shapes have 5 and 6 points.

[Diagram]
Critical shape 5 (6 points) "The Rabbitty Six"  

Rabbitty Six

[Diagram]
Critical shape 6 (5 points) "The Bulky Five"  

Bulky Five

In all of these critical shapes the critical point is the center of the cross.

There are other critical shapes in the corner that depend on shortage of liberties.

-- Bill Spight


See also


Killable Eyeshapes Introductory last edited by 172.150.12.72 on May 5, 2007 - 15:26
RecentChanges · StartingPoints · About
Edit page ·Search · Related · Page info · Latest diff
[Welcome to Sensei's Library!]
RecentChanges
StartingPoints
About
RandomPage
Search position
Page history
Latest page diff
Partner sites:
Go Teaching Ladder
Goproblems.com
Login / Prefs
Tools
Sensei's Library