Flying Saucer Shape

    Keywords: Life & Death

The Flying Saucer Shape is a special case of the Two Space Notchers (c) James Davies, moreover Two Space Notchers Not Fully Connected. 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]

The Flying Saucer Shape is dead

What matters is that the black group is blocked at the second line (WC stones), and that its weak spots are occupied (WS 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 Two Space Notchers Not Fully Connected.

[Diagram]

Attempt 1

White cuts at the other side than the one Black protects, then gives atari. She finishes off with W6, keeping Black at one eye. The position is symmetric, so if B1 at 3 then W2 at 5.

[Diagram]

Attempt 2

Black ends up with a 3 point big eye with W2 already at the vital point.

[Diagram]

Attempt 3

After W2, Black has a shape similar to six on the second row. He's dead. B3 gives major resistance, but after W4, she can almost fill Black's eye space with three stones any time.

[Diagram]

Attempt 4

This reverts to attempt 3.

[Diagram]

Attempt 5

[Diagram]

Attempt 5 - alternative


This is a copy of the living page "Flying Saucer Shape" at Sensei's Library.
(OC) 2005 the Authors, published under the OpenContent License V1.0.
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