Compromised diagonals and joseki 1
If White is free to extend alone the upper side, then the exchange of
and
is in principle good for White. For one thing, playing
at
is joseki (3-4 point high approach outside contact).
Given a black stone at
(or at the marked point), the exchange
/
is some improvement for Black: it possibly makes White heavier. Black now at a leaves White's stones floating.
White's other natural resource is at
here. There is a ladder question involved. In pro games
may only be played when the ladder is good for Black: for example if White invades late and Black has some central influence.
A second ladder (Black at a) can occur if White rejects the chance to live small here after
(with
at
). This position comes from an Oteai game Yoda Norimoto-Komatsu Hideki (B) 1983-06-29.
BobMcGuigan I don't think I'd want to play
in the first diagram above without some support to the right or, perhaps in a Chinese Opening type of situation, but I wondered how bad this move could be even if the ladders favor white.
For example, if things went as in the next diagram, it is clearly a bad result for Black since the marked stone is in the wrong place (it should be at a or b).
Andre Engels: I assume this is more or less equal, given that
-
-
is a joseki, (although both a and b are clearly more common than
). The joseki is discussed in 3-4 point high approach, double contact, wall
![[Diagram]](../../diagrams/31/65cb20ea89da0739c356b02fce091edd.png)
![[Diagram]](../../diagrams/48/56fe59c9d4dc7211946e4b964cb4c00d.png)
![[Diagram]](../../diagrams/33/b933dd3f87ccca459577b4cfe51391b7.png)
![[Diagram]](../../diagrams/19/d7946124019dc349f84beae3800a00dd.png)
![[Diagram]](../../diagrams/17/e226036682071544631cc5bc4d94dbc8.png)
is bad for White, ![[Diagram]](../../diagrams/31/5bd3a4e1d2f98f60fa675b8cbf6dd175.png)
![[Diagram]](../../diagrams/42/200b3a7e0d87a1736270b3f251635ab6.png)
![[Diagram]](../../diagrams/31/53ae31794d99442c20faa34be32245a6.png)
2024 the Authors,
published under the ![Sensei's Library [Welcome to Sensei's Library!]](../../images/stone-hello.png)