Introduction
The lesson video is the following
Main position
During this lesson, we’ve seen how to manage the approach or invasion of the high large 3-4 enclosure.
Black can simply choose to defend with a move at the triangle intersection or tenuki.
Black tenuki
If black tenuki, the key point is the attachment at 1. Black can either hane on the top or bottom has shown in the diagram below.
If black hane on the top, then the following sequence can be played. After 7, black can choose to tenuki, or extend at A.
If the ladder is good for white, he can choose to play at 3 instead of 3 in the previous diagram.
A and B are both good continuation and it will depend on the distribution. A is good in this particular distribution.
Black extended
We also had a look at the situation when black already extended on the side.
The key invasion point is now at 1.
Black blocks on top
If black on top, white can easily live in the corner by jumping at the san-san.
After 9, white can play either A or B to live, so he is 100% alive.
If black blocks the side, again the key move is on the san-san.
After 8, white can simply connect at 9, it is not a ko and white is alive.
Indeed, if black tries to kill directly by pocking at 1 and connecting at 3, then white can play at 4 and destroy black shape.