Life In 19x19

Hi all,

Reviewing a couple of positions that came up in my games today. One of them is a common problem I come up against, and it's about time I got some outside input, the other was something new for me.

First position/question;



If Black gets the opportunity to the move 7 here, I've seen the "correct" response for White to be to jump out. However, what I see in my games is the sequence shown, where white pushes etc., I'm not sure what the best response for Black is, and whether getting my corner solidified is compensation for white not jumping?

The second position was the invasion as below, starting from 7, ignore the prior move order;


After the sequence 7 through to 20, is the best move for B to play the clamp as shown? Is there a better way to have played for either sides, to invade under such an enclosure?


Many thanks,

Zac

Q1: Several choices:
- tenuki, your side move is bigger than his 2nd line push so you already gained. Compare to the joseki where he approaches, you jump, he slides, you pincer, then he plays 3-3, but here you got the 3-3 so his eyespace is much smaller.
- cover at o16, let him live on side. Connecting your stones is valuable, and centre potential.
- answer in corner, he's still not alive and profit as chase him out.

Q2: s3 at s2 for a ko which is very damaging if white loses. It's possible to make an unconditional life (see https://senseis.xmp.net/?Butterfly#diag4), but it's generally better to live big via ko with attitude than grovel out a small gote life whilst your opponent gets super thick.

Q3 got lost?

Uberdude wrote:Q1: Several choices:
- tenuki, your side move is bigger than his 2nd line push so you already gained. Compare to the joseki where he approaches, you jump, he slides, you pincer, then he plays 3-3, but here you got the 3-3 so his eyespace is much smaller.
- cover at o16, let him live on side. Connecting your stones is valuable, and centre potential.
- answer in corner, he's still not alive and profit as chase him out.

Q2: s3 at s2 for a ko which is very damaging if white loses. It's possible to make an unconditional life (see https://senseis.xmp.net/?Butterfly#diag4), but it's generally better to live big via ko with attitude than grovel out a small gote life whilst your opponent gets super thick.

Q3 got lost?

Thanks very much.
This all makes a lot of sense. For Q1 I'll keep those three options in mind and try out my judgement about which is best given the rest of the board.

As for the ko in Q2, in the game I played this would have been pretty devastating for my opponent. I would have had many more ko threats than he did. This turned out to be one of the best losses I've had for a long time, one of those really instructional games. Ended up losing by 10ish, but had some pretty clear things to work on after the review. It's much nicer than having absolutely no idea where things went wrong.

Question 3, I ended up making a different post as it was a more general question, and I forgot to change the title here.


Thanks again,

Zac