4-4 7-3 enclosure 3-3 invasion

The 3-3 invasion  

This is the main variation of White's 3-3 invasion of the enclosure. may also be played at (see below).

Tapir: What happens after at ? When black needs sente this may be better. Why isn't it mentioned at all? (Or is the inside hane preferred then?)

For at see 4473 enclosure 3-3 invasion, block on inner side.

Main variation, continued  

tderz or b.
Bd is then sente, White replies with e.
No matter how White connects, there is always a Black threat from the side.

Dave: However, the threat is different (which may affect the choice of connection), see below.

This is the standard line, and White ends in sente. The White group is an L+2-group and is alive. Black though has considerable influence now.

Variants:

1. at a, challenging to a ko.
2. at b. This affects forcing moves (Black d is then sente against the corner), and endgame plays in the corner. With as played, Black c threatens a ko in the corner.
3. Black on occasion omits net example 5, but then White at causes a fight.

Different Connection - Different Threats:

Solid connection, Black's sente  

Dave: With the solid connection here is sente. White can not live unconditionally if Black plays next at . White is caught in dame zumari after and can not intercept at a. If were not on the board, White would live. Here White has no choice but to start a ko with 6 at 7. This is an indirect ko. Playing b instead of 1 does not threaten White.

Hanging connection, Black's sente  

Dave: With the hanging connection, White dies outright after and . The play at a instead of 1 does not threaten White.

Another way  

Black may also play this way. Then (or a) lives. here is proper, but may be omitted: if Black wants to end in sente here it may make sense to play in this manner, rather than follow the above main variation.

More common  

Dave: Note that this is significantly more common than 6 in actual professional play.

More common, cont'd  

Dave: At this point Black usually plays tenuki but may force with a first.

Dieter: Question. at a reduces the corner to an L+1-group, whose status depends on sente. So Black can play a in sente ?

Kikashi  

Here is certainly a good kikashi against the corner. And here is a useful way to follow it up, for fighting purposes, since it still threatens the corner. It is unlikely to be the correct endgame play, though, in typical situations.

Inverting the order  

Dieter: If White inverts the order, he'll get into trouble with . Black can answer the cut at . Next, ...

The fight  

... the fight is influenced by neighbouring stones. If Black is strong in the area, White cannot hope for much. Therefor, ...

The clamp  

White may clamp but she'll be in dire straits anyway.

inside hane  

How to proceed now for white?

Joseki  

Joseki (Cont.)  

If Black does not return to , then later White can clamp at a to split Black or cut at b or c.