Killable eye shapes

    Keywords: Life & Death

This page discusses all killable eyeshapes, including those where there is more than one White stone inside Black's eye space, but the position is not seki.

  • Positions with cutting points are not included.
  • Side or corner positions are not included.
  • Red circles indicate how White can almost fill the black eye space.
  • The effective number of internal liberties is included (big eyes).
  • The diagrams show the minimum number of internal White stones required to kill Black's group. If the shape is empty ...
    • 0: ... Black's group is dead as it stands;
    • 1: ... Black's group is unsettled. Strike at the vital point;
    • 2 or more: ... Black's group is alive as it stands.

One point shapes

[Diagram]
Shape #1  

Number of internal points: 1
Required number of internal White stones to kill: 0
Remaining internal moves to capture: 1
Total internal liberties: 1



Two point shapes

[Diagram]
Shape #2  

Number of internal points: 2
Required number of internal White stones to kill: 0
Remaining internal moves to capture: 2
Total internal liberties: 2



Three point shapes

[Diagram]
Shape #3.1  

Number of internal points: 3
Required number of internal White stones to kill: 1
Remaining internal moves to capture: 2
Total internal liberties: 3
Other names: straight three


[Diagram]
Shape #3.2  

Number of internal points: 3
Required number of internal White stones to kill: 1
Remaining internal moves to capture: 2
Total internal liberties: 3
Other names: bent three


Four point shapes

[Diagram]
Shape #4.1  

Number of internal points: 4
Required number of internal White stones to kill: 0
Remaining internal moves to capture: 5
Total internal liberties: 5
Other names: squared four, four in a box?


[Diagram]
Shape #4.2  

Number of internal points: 4
Required number of internal White stones to kill: 1
Remaining internal moves to capture: 4
Total internal liberties: 5
Other names: Pyramid Four


[Diagram]
Shape #4.3  

Number of internal points: 4
Required number of internal White stones to kill: 2
Remaining internal moves to capture: 3
Total internal liberties: 5
Other names: straight four


[Diagram]
Shape #4.4  

Number of internal points: 4
Required number of internal White stones to kill: 2
Remaining internal moves to capture: 3
Total internal liberties: 5
Other names: twisted four, dogleg four


[Diagram]
Shape #4.5  

Number of internal points: 4
Required number of internal White stones to kill: 2
Remaining internal moves to capture: 3
Total internal liberties: 5
Other names: bent four



Five point shapes

[Diagram]
Shape #5.1  

Number of internal points: 5
Required number of internal White stones to kill: 1
Remaining internal moves to capture: 7
Total internal liberties: 8
Other names: bulky five, [ext] P


[Diagram]
Shape #5.2  

Number of internal points: 5
Required number of internal White stones to kill: 1
Remaining internal moves to capture: 7
Total internal liberties: 8
Other names: Crossed Five, Greek Cross, [ext] X


[Diagram]
Shape #5.3  

Number of internal points: 5
Required number of internal White stones to kill: 2
Remaining internal moves to capture: 6
Total internal liberties: 8
Other names: [ext] Y


[Diagram]
Shape #5.4  

Number of internal points: 5
Required number of internal White stones to kill: 2
Remaining internal moves to capture: 6
Total internal liberties: 8
Other names: [ext] T


[Diagram]
Shape #5.5  

Number of internal points: 5
Required number of internal White stones to kill: 2
Remaining internal moves to capture: 6
Total internal liberties: 8
Other names: [ext] F



Six point shapes

[Diagram]
Shape #6.1  

Number of internal points: 6
Required number of internal White stones to kill: 1
Remaining internal moves to capture: 11
Total internal liberties: 12
Other names: Rabbitty Six

Problems

[ext] http://www.goproblems.com/prob.php3?id=2295

[Diagram]
Shape #6.2  

Number of internal points: 6
Required number of internal White stones to kill: 2
Remaining internal moves to capture: 10
Total internal liberties: 12
Other names: Rectangular Six


[Diagram]
Shape #6.3  

Number of internal points: 6
Required number of internal White stones to kill: 2
Remaining internal moves to capture: 10
Total internal liberties: 12


[Diagram]
Shape #6.4  

Number of internal points: 6
Required number of internal White stones to kill: 2
Remaining internal moves to capture: 10
Total internal liberties: 12


[Diagram]
Shape #6.5  

Number of internal points: 6
Required number of internal White stones to kill: 4
Remaining internal moves to capture: 8
Total internal liberties: 12


[Diagram]
Shape #6.6  

Number of internal points: 6
Required number of internal White stones to kill: 4
Remaining internal moves to capture: 8
Total internal liberties: 12



Seven point shapes

[Diagram]
Shape #7.1  

Number of internal points: 7
Required number of internal White stones to kill: 2
Remaining internal moves to capture: 15
Total internal liberties: 17


[Diagram]
Shape #7.2: Three possible patterns for White.  

Number of internal points: 7
Required number of internal White stones to kill: 3
Remaining internal moves to capture: 14
Total internal liberties: 17
Other names: Butterfly Seven

[Diagram]
Shape #7.3  

Number of internal points: 7
Required number of internal White stones to kill: 3
Remaining internal moves to capture: 14
Total internal liberties: 17


[Diagram]
Shape #7.4  

Number of internal points: 7
Required number of internal White stones to kill: 4
Remaining internal moves to capture: 13
Total internal liberties: 17



An eye in the stomach

From 8 points onwards, there are no killing lumps anymore, and the stones inside the eye must (be able to) make an eye themselves, though not a real eye as we usually understand it. An example:

[Diagram]
Shape #8.1  

Number of internal points: 8
Required number of internal White stones to kill: 4

Adding a stone at any of the marked points, Black dies, as White connects at a.
If White starts to actually remove the Black stones from the board, he should not play at a, because this will turn the position into seki.



See also


Authors

  • GijsD
  • Dieter (a few additions)

Killable eye shapes last edited by Tel on September 23, 2017 - 06:31
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