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Flying Saucer Shape
    Keywords: Life & Death

The Flying Saucer Shape is a special case of the TwoSpaceNotchers (c) James Davies, moreover TwoSpaceNotchersNotFullyConnected. The term Flying Saucer I made up myself and I'm not convinced it will make history. I just needed a pagename a bit catchier than Two Space Notcher With Both Weak Points Occupied. --DieterVerhofstadt.

See Kanazawa Problem 23 for a interesting problem involving the Flying Saucer Shape.


The Flying Saucer Shape is dead

[Diagram]
Diag.: The Flying Saucer Shape is dead

What matters is that the black group is blocked at the second line (the circled white stones), and that its weak spots are occupied (the squared white stones). What does not matter is whether the circled liberties are occupied or not.

Let's see some attempts by Black to live. For a general treatment, see TwoSpaceNotchersNotFullyConnected.


[Diagram]
Diag.: Attempt 1

White cuts at the other side than the one Black protects, then gives atari. She finishes off with 6, keeping Black at one eye. The position is symmetric, so if Black 1 at 3 then White 2 at 5.


[Diagram]
Diag.: Attempt 2

Black ends up with a 3 point big eye with 2 already at the VitalPoint.


[Diagram]
Diag.: Attempt 3

After 2, Black has a shape similar to six on the second row. he's dead. Black 3 gives major resistance, but after White 4, she can AlmostFill Black's EyeSpace with three stones any time.


[Diagram]
Diag.: Attempt 4

This reverts to attempt 3.


[Diagram]
Diag.: Attempt 5

[Diagram]
Diag.: Attempt 5 - alternative


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