RobertJasiek wrote:
Harleqin wrote:
in the sequence you show, either

or

is misplaced.
White's shape is equally bad (also with empty triangle), so it does not matter that B has an empty triangle.
I think that if Black has to invest that peeping stone, the inefficiencies of that black stone and the awkward white stone compensate to a certain degree (but I am not sure whether White should not answer the peep differently). One would not say that a tiger's mouth is inefficient just because it could be peeped, right? The black empty triangle seems to have a harder time to justify itself, in my eyes. I have some more thoughts about this efficiency issue, but that is another post on another day, I think.
Quote:
Quote:
- Click Here To Show Diagram Code
[go]$$B
$$-------------------------------------
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . X . . . . . , . . . . . X . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . , . . . . . X . . . . . , . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . O c . . |
$$| . . . . . . . . . . . . . 3 . 5 d . . |
$$| . . . . . . . . . . . . 2 1 a . X . . |
$$| . . . X . . . . . , . . b O 4 X . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$-------------------------------------[/go]
This shape is more efficient
No. It just has other (dis)advantages. After White c, White d threatens more than in my variation.
After white 'c', Black cuts at 'b', the way I see it. You cannot have everything. By the way, 'd' looks dubious to me: the white group does not gain a single liberty. Black can answer the threat in many ways that gain much more than 'd'. Example continuation:
- Click Here To Show Diagram Code
[go]$$W
$$-------------------------------------
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . X . . . . . , . . . . . X . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . a . . |
$$| . . . , . . . . . X . . . . . , . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . O 1 . . |
$$| . . . . . . . . . . . . 8 X . X 3 . . |
$$| . . . . . . . . . . . 9 O X . . X . . |
$$| . . . X . . . b . , . 5 2 O O X . . . |
$$| . . . . . . . . . . . 7 6 . . 4 . . . |
$$| . . . . . . . . . . . . . 0 . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$-------------------------------------[/go]
Again a miai situation. If White plays on the right side first, before

, I think that Black should take the left side with

or 'a':
- Click Here To Show Diagram Code
[go]$$W
$$-------------------------------------
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . X . . . . . , . . . . . X . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . 3 . . |
$$| . . . , . . . . . X . . . . . , . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . O 1 . . |
$$| . . . . . . . . . . . . . X . X d . . |
$$| . . . . . . . . . . . . O X . . X e . |
$$| . . . X . . . . . , . 4 2 O O X . . . |
$$| . . . . . . . . . . . . a . . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$-------------------------------------[/go]
After that, 'd' would be answered by 'e'.
If White initially protects the cut on the left instead, the white stone on the right becomes "blighted". Note how immobilized it is compared to the situation where Black would now perhaps pincer this stone after making the empty triangle:
- Click Here To Show Diagram Code
[go]$$W
$$-------------------------------------
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . X . . . . . , . . . . . X . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . , . . . . . X . . . . . , . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . O 2 . . |
$$| . . . . . . . . . . . . . X . X . . . |
$$| . . . . . . . . . . . . O X . . X . . |
$$| . . . X . . . . . , . 1 . O O X . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$-------------------------------------[/go]
- Click Here To Show Diagram Code
[go]$$W
$$-------------------------------------
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . X . . . . . , . . . . . X . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . , . . . . . X . . . . . 2 . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . O . . . |
$$| . . . . . . . . . . . . . X . . . . . |
$$| . . . . . . . . . . . . O X X . X . . |
$$| . . . X . . . . . , . 1 . O O X . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$-------------------------------------[/go]
Now, if White plays on the right side, as you proposed, instead of starting this double approach immediately, it would threaten the second approach, as the right side group would have its base already. However, it would feel bad for Black to answer the approach move twice like this:
- Click Here To Show Diagram Code
[go]$$W
$$-------------------------------------
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . X . . . . . , . . . . . X . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . 1 . . |
$$| . . . , . . . . . X . . . . . , . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . O . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . B . . |
$$| . . . X . . . . . , . . . 2 . X . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$| . . . . . . . . . . . . . . . . . . . |
$$-------------------------------------[/go]
So, finally, I think that this

is the right move, perhaps even a refutation of

.
Edit: add comparison diagram.