Double Hasami - Occupy Three-Three
, the second approach, is a double kakari. In response Black plays
back into the corner, at the 3-3 point.
is the double hasami; or, you could say,
creates a position in which Black has been pincered twice.
It is best to play this way only
when is previously played (or is already there, in a
handicap game). Black is guaranteed life in the corner, with best play; and
can cut if White tries to seal Black into the corner. Then
White will have two weak groups
and a difficult game.
This is a tough-minded strategy, forming an exception to the idea that one should not become shut in. White can indeed shut in the corner with a play at a, now. Black will be able to cut White, and White shouldn't be able to kill the corner.
See BQM48 for a fuller discussion.