[go]$$W Variation A
$$ ---------------------
$$ . . . . 3 1 a 2 . . |
$$ . . . . O X O O X . |
$$ . . . . O X X X X . |
$$ . . . . . . . . . . |[/go]
However, if throws in first, after still connects as above,
the situation is different -- later, W can capture at (b).
The points are different from variation A.
$$W Variation B
$$ ---------------------
$$ . . . . 3 1 2 b . . |
$$ . . . . O X O O X . |
$$ . . . . O X X X X . |
$$ . . . . . . . . . . |
[go]$$W Variation A
$$ ---------------------
$$ . . . . 3 1 a 2 . . |
$$ . . . . O X O O X . |
$$ . . . . O X X X X . |
$$ . . . . . . . . . . |[/go]
However, if throws in first, after still connects as above,
the situation is different -- later, W can capture at (b).
The points are different from variation A.
$$W Variation B
$$ ---------------------
$$ . . . . 3 1 2 b . . |
$$ . . . . O X O O X . |
$$ . . . . O X X X X . |
$$ . . . . . . . . . . |
[go]$$W Variation B
$$ ---------------------
$$ . . . . 3 1 2 b . . |
$$ . . . . O X O O X . |
$$ . . . . O X X X X . |
$$ . . . . . . . . . . |[/go]
I'm currently reading a book about Yose.
For now I have only read 1/4 of the book, but that allready changed my undertsanding of sente...
For example, till now, was sente for me... but, it's not. or at least not necessarily (still ignoring life-and-death considerations here)...
so I think black has to count the value of capturing the two stones, and see if there is something bigger somwhere else...
Let's try to count the points... (warning, That's the first time I'm doing this, that may be all wrong...)
Variation A
$$B Variation A, black yose
$$ ---------------------
$$ . . . . O O 1 X S . |
$$ . . . . O X @ @ X . |
$$ . . . . O X X X X . |
$$ . . . . . . . . . . |
[go]$$B Variation A, black yose
$$ ---------------------
$$ . . . . O O 1 X S . |
$$ . . . . O X @ @ X . |
$$ . . . . O X X X X . |
$$ . . . . . . . . . . |[/go]
black : 5 pts (2 catures + 3 pts local territory, in gote
white : 0 pts
so I would say black +5
$$W Variation A, white yose ()
$$ ---------------------
$$ . . . . O O 1 X a . |
$$ . . . . O X O O X . |
$$ . . . . O X X X X . |
$$ . . . . . . . . . . |
[go]$$W Variation A, white yose ()
$$ ---------------------
$$ . . . . O O 1 X a . |
$$ . . . . O X O O X . |
$$ . . . . O X X X X . |
$$ . . . . . . . . . . |[/go]
black : 0
white : 2 (2 is my approximation for white's privilege at a)
so it's black -2 in this case
Which means the global value of yose of vvariation A is 3 points in gote...
Before I will do variation B, can someone tell if I'm full wrong in my calcultation or if I'm somehow correct ?
Re: How to respond in this case?
Posted: Mon Nov 17, 2014 4:55 am
by Uberdude
I don't know we we are hiding everything, making it harder to read things.
EdLee wrote:
If atari directly, after connects,
then later B can take at (a), or W can connect at (a):
$$W Variation A
$$ ---------------------
$$ . . . . 3 1 a 2 . . |
$$ . . . . O X O O X . |
$$ . . . . O X X X X . |
$$ . . . . . . . . . . |
[go]$$W Variation A
$$ ---------------------
$$ . . . . 3 1 a 2 . . |
$$ . . . . O X O O X . |
$$ . . . . O X X X X . |
$$ . . . . . . . . . . |[/go]
However, if throws in first, after still connects as above,
the situation is different -- later, W can capture at (b).
The points are different from variation A.
$$W Variation B
$$ ---------------------
$$ . . . . 3 1 2 b . . |
$$ . . . . O X O O X . |
$$ . . . . O X X X X . |
$$ . . . . . . . . . . |
[go]$$W Variation B
$$ ---------------------
$$ . . . . 3 1 2 b . . |
$$ . . . . O X O O X . |
$$ . . . . O X X X X . |
$$ . . . . . . . . . . |[/go]
Ed is correct that the points are different in B. However, he seems to be suggesting B is worse and throw in was a mistake. It is not. Variation B is better for black in terms of yose: if white captures black gets to keep 3 points in the corner in sente (so net 2 for black), in A he doesn't. The calculation of the value of the ko moves round the corner for A after white connects is tricky, but it seems to be net 4/3 for black, i.e. 2/3 of a point worse than B.
So well done gostudent for having good basics of how to capture those two stones. However as has been pointed out and you noticed, white had a serious cut in the game shape so you can live by capturing lots more. Also throw-in is better because it has a better follow-up if ignored (for example if white fixes that cut) of capturing 1 stone on the top side instead of no followup like the connect-and-die. In fact all this minutae is kind of irrelevant when the previous moves didn't make sense, for example 10 should just cut as below and white collapses. White is trying to fill black's liberties but has too few liberties himself. (5 and 7 were pretty crazy too).
Also the premise of white connecting and black not capturing is rather unusual: if black won't capture why does white want to connect? For the throw in there is some value of saving 1 stone, for Ed's atari there is no value so it would only happen as a ko threat or if that connection did something useful on the top side.
Re: How to respond in this case?
Posted: Tue Nov 18, 2014 3:50 am
by Uberdude
Interestingly, there is one situation where Ed's atari is better than the throw in, namely it can be better for eyeshape if black is short of liberties and white's outside is strong:
$$B Alive
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . O . 1 . . |
$$ | . . . . . . . . . . . O . O X O O X 3 |
$$ | . . . . . . . . . . . . . O X X X X 2 |
$$ | . . . X . . . . . , . . . O X X O O . |
$$ | . . . . . . . . . . . . . X O O . . . |
$$ | . . . . . . . . . . . . . . . . O O . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------
[go]$$W Variation A
$$ ---------------------
$$ . . . . 3 1 a 2 . . |
$$ . . . . O X O O X . |
$$ . . . . O X X X X . |
$$ . . . . . . . . . . |[/go]
However, if throws in first, after still connects as above,
the situation is different -- later, W can capture at (b).
The points are different from variation A.
$$W Variation B
$$ ---------------------
$$ . . . . 3 1 2 b . . |
$$ . . . . O X O O X . |
$$ . . . . O X X X X . |
$$ . . . . . . . . . . |
[go]$$W Variation A'
$$ ---------------------
$$ . . . . b 1 a 2 . . |
$$ . . . . O X O O X . |
$$ . . . . O X X X X . |
$$ . . . . . . . . . . |[/go]
After "a" and "b" are miai.
Obviously the local scores resulting from the throw-in and the hane are equal. However, the hane is superior in terms of ko threats and tactics (as Uberdude has shown). (If there is a situation where the throw-in is superior, I am unaware of it.)
Re: How to respond in this case?
Posted: Tue Nov 18, 2014 8:40 am
by Uberdude
Bill Spight wrote: (If there is a situation where the throw-in is superior, I am unaware of it.)
The (admittedly bizarre) situation that Ed proposed of white prematurely connecting at 3 and black playing tenuki afterwards because white's connect was too early and a bad move.
Re: How to respond in this case?
Posted: Tue Nov 18, 2014 8:51 am
by Knotwilg
Good analysis.
Re: How to respond in this case?
Posted: Tue Nov 18, 2014 8:54 am
by Bill Spight
Uberdude wrote:
Bill Spight wrote: (If there is a situation where the throw-in is superior, I am unaware of it.)
The (admittedly bizarre) situation that Ed proposed of white prematurely connecting at 3 and black playing tenuki afterwards because white's connect was too early and a bad move.
atari directly, after 
connects,
local territory, in gote
in this diagram "a" and 2 are miai. Then White has a ko threat in the eye.