I don't know we we are hiding everything, making it harder to read things.



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).

Click Here To Show Diagram Code

[go]$$W
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . 3 2 5 7 . . |
$$ | . . . . . . . . . . . . . O X 6 4 8 . |
$$ | . . . X . . . . . , . . . O X X 1 9 . |
$$ | . . . . . . . . . . . . . X O O 0 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

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.

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:

Click Here To Show Diagram Code

[go]$$B Alive
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . O . 1 . . |
$$ | . . . . . . . . . . . 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]

Click Here To Show Diagram Code

[go]$$B Dead as 5 self atari (and black capture of 2 stone to gain liberty is gote)
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . O 1 4 5 . |
$$ | . . . . . . . . . . . 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]

Click Here To Show Diagram Code

[go]$$W Variation C
$$ ---------------------
$$ . . . . a 1 2 3 4 . |
$$ . . . . O X O O X . |
$$ . . . . O X X X X . |
$$ . . . . . . . . . . |[/go]

in Variation B is a mistake, losing 1/3 point on average.

After in this diagram "a" and 2 are miai. Then White has a ko threat in the eye.

Click Here To Show Diagram Code

[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.)

_________________
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

Visualize whirled peas.

Everything with love. Stay safe.

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.

Good analysis.

_________________
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

Visualize whirled peas.

Everything with love. Stay safe.