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BulkyFive
UnsettledEyeshapes
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ButterflySeven
TheEmptyTriangleI...
AStaticTreatiseOn...
GoTerms
KanazawaSolution41
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ChineseGoTerms
FarmerSHatEyeSpace
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BeginnerExercise1...
KanazawaSolution36
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July28Solution2

 

Farmer's Hat
Path: KillingShapes   · Prev: SquareFour   · Next: BulkyFive
  Difficulty: Beginner   Keywords: Shape, Go term

[Diagram]
The farmer's hat

The farmer's hat refers to the shape of stones or empty points that form the [circled point] shape as shown in this diagram.

It is used to denote either a killable eye shape or a bad shape.



[1] The farmer's hat as a killable eye shape
[2] The farmer's hat as a bad shape
[3] Discussion

[1] The farmer's hat as a killable eye shape

[Diagram]
The farmer's hat

The farmer's hat is a basic idea in life and death, it is a big eye with a being the vital point. If Black plays at a, he as three eyes; and if White plays at a, Black is dead. The farmer's hat has five inside liberties.


[Diagram]
Almost fill

After White occupies the vital point, it is possible to almost-fill the shape into the straight three dead shape.


[Diagram]
Almost fill

Alternatively, it is possble to almost-fill into bent three.



See also


[2] The farmer's hat as a bad shape

[Diagram]
The farmer's hat

The farmer's hat is a bad shape, for the same reason that the empty triangle is bad. You can think of this shape as two empty triangles.

The liberty at a (and similarly for b) is inefficient (see the empty triangle is bad page for more details).

If White plays at a or b, it actually would improve Black's shape. If both points are filled by White then the shape is really good.


[Diagram]
Very bad shape for Black

In situations like this, the farmer's hat is really ridiculous.

The BC stone has to be at a.


[Diagram]
Black cannot cut at 'a'

Black's bad shape allows White to play W1. Black cannot cut at a. Furthermore the [circled point] point is a false eye.



[3] Discussion

I've heard this also called the Soldier's Helmet. -- Blue Wyvern

I've also seen Napoleon's Hat. -- Nico

It is often mentioned as the "pyramid" too. -- ddom

Yes, in Holland we use the term "pyramid".

Robert Pauli: My favorite name for this shape is dead-end four - makes sense in all directions, looks like the street sign (the stem a bit short, though), and clearly gives the message.


Authors



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This is a copy of the living page "Farmer's Hat" at Sensei's Library.
(OC) 2004 the Authors, published under the OpenContent License V1.0.