Life In 19x19

peppernut wrote: Yet überdude also likes this move, so there has to be merit to this move that I'm not understanding. Can you explain it?

Pretty much exactly what David said; I was too lazy to make diagrams. The key points are
1) If you capture the stones in a ladder the nobi becomes a wasted move, so atari first is a kind of probe asking if white wants to let you capture more stones in a ladder which is obviously much better.
2) If white gets to nobi his shape is better and he gets out faster, David's 2a/2b is a nice example of this
3) Stop the first line connection.

P.S. for David: throw in at 6 in 1a could be a mistake and direct atari may be better: if black is going to tenuki the 1st line atari after the throw-in (which is usually the case) then the throw in reduces the yose value of taking the 3 stones as black can recapture so unless taking that black eye is strategically valuable the throw-in loses points (but is a very natural instinct I have to fight!).

Uberdude wrote:P.S. for David: throw in at 6 in 1a could be a mistake and direct atari may be better: if black is going to tenuki the 1st line atari after the throw-in (which is usually the case) then the throw in reduces the yose value of taking the 3 stones as black can recapture so unless taking that black eye is strategically valuable the throw-in loses points (but is a very natural instinct I have to fight!).

Yea, I hesitated on that move too, when making the diagram. Without seeing the rest of the board it's hard to say for sure. However I feel that if I were white I'd choose to play the throw in here, because it indirectly strengthens the pincer stone at Q10, which black is probably about to turn to attacking with sente (either way).

To be honest, I think that this sort of variation should hardly ever happen anyway, amongst strong players, because black becomes too thick if he plays well (I meant to say that earlier). Both players have to make several mistakes to reach that position under normal circumstances, but if it gets there, white still has more scope to hang tough when black plays the extension.

In this case I feel white can afford to pay a few points locally to remove the half eye, because she can gain more than that back on the right side with the leverage it creates, but I tend to be the kind of player who favors keeping positions unsettled for as long as possible, at the expense of hard cash. Think WWSD - what would Seo (Bongsu) do?

Also, the throw in better demonstrates how inferior black's shape is with the extension, for the sake of that example. I definitely agree that the throw in would be a mistake in the examples where where black captures three stones, because it achieves less than nothing in those cases.

Anyway, I can't say one is better than the other for sure here. Maybe a stronger player could, but I guess that's why we have the notion of style. Everyone weights the balance between territory and future attacking potential differently.

Anyway it's an interesting choice to think about and discuss, thanks Andrew.

P.S. I added a link to your tournament table here: http://gogameguru.com/links/ - Korea almost looks resurgent right now, but with so little data it's too random to say.

Yeah, in that case the big black group doesn't actually have two eyes yet so although it's pretty huge and unlikely to get into trouble, you never know what could happen in the fighting and that half eye could come in handy. I mentioned that throw-in because the issue arose in a recent tournament game of mine where the group did have two clear eyes so the throw-in was a definite mistake in that case, see move 66:
I've just realised another potential downside of the throw-in, but one that's pretty unlikely to ever come up: it does actually give more liberties to the outside black stones which become solidly connected so there could be some situation in which a ladder or other form of damezumari crashing into them is affected.

Thanks David, execllent clarification. There is a lot more going on in the position than I thought.

Wow... I didn't expect that this question will become a very discussed one!

Thank you all, especially David who gave such nice explanations!