Loose ladder

  Difficulty: Beginner   Keywords: Tesuji, Tactics

Chinese: 缓征 (huan3 zheng1); 缓征子 (huan3 zheng1 zi3)
Japanese: 緩みシチョウ / 緩征 (yurumi shicho)
Korean: 빈축

In a loose ladder the stones to be captured have at most three liberties, and are constantly reduces back to two liberties. (instead of at most two, being constantly reduced back to one, as in a normal ladder).

Examples

[Diagram]

Black to play.

Can Black capture white+circle?

[Diagram]

Loose ladder

[Diagram]

Black to play

White has just cut with white+circle, what can black do?

[Diagram]

Loose ladder 2

[Diagram]

Loose ladder 2, cont'd


For an even more extreme example, see Hayashi Gembi's Loose Ladder

Discussion

Q: Is this something different from a net?

--Stefan

BillSpight: Interesting question. :-) I suppose you could consider it a kind of net, but it's more specific.

[Diagram]

Net

B1 is a net, but not a loose ladder.

Why would you bother, instead of simply capturing and removing bad aji

DieterVerhofstadt:

The way I see it, is that a ladder is a capturing technique where the liberties of the chased chain flip between one and two until the defending side is unable to raise the liberties to two again.

A loose ladder would follow exactly the same definition, replacing 1 by 2 and 2 by 3 respectively.

A net on the other hand is a capturing technique so that the liberties of the chased chain can't be increased by the defender's next move.

This contradicts Bill's statement above, but I'm ready to adopt another viewpoint on these definitions.

[Diagram]

geta 1

[Diagram]

geta 2

Both basic examples of net meet my definition.


jvt: Your definition is too restrictive. (Example moved to Net example 7.)

(Well if it is a ladder it is not a net!)

jvt: A successful loose ladder always ends in a ladder (in order to decrease the liberty count from three to zero, you have to go through a stage of 1/2 liberties.

Bill: One thing that a loose ladder and a ladder share, that a net does not, is that they each reduce the liberties of the chain of stones to be captured by one with each play. In a ladder each play is atari. The typical play in a loose ladder is not.


This is a copy of the living page "Loose ladder" at Sensei's Library.
(OC) 2011 the Authors, published under the OpenContent License V1.0.
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