Play Kikashi Before Living/ Old

kb: All old content moved here

TODO: Amend the example. See my comment at the bottom of the page.

Adapted from Gokyo Shumyo, Section 1, Problem 21 / Solution.

Correct

White can live with either a or b, but plays kikashi with before living.

No kikashi

If White immediately takes a vital point, she lives too, but now she has failed to force Black. If White plays later in the game, the value of that move is reduced to 4+ [2] points, and Black can choose to ignore it. If White eventually captures the stones with and , Black can make shape with and . Also, has now been turned into a superfluous move, a one-point loss.

Difference

The difference with the correct diagram is that, if Black ignores , then the capture of the stones yields not merely 4 points[2], but also life for the corner[1]. Now look again at the previous diagram, which is as if White plays at a here, in exchange for a black move elsewhere, really a ridiculous turn of events. --DieterVerhofstadt

aLegendWai: I have more ideas relating to the gain of capturing 2 . Click on [3] for details.

aLegendWai: I am not in a good position to raise argument because I am a very weak player. Anyway, I just try to express my hesitation. You may disagree with it entirely.

Takemiya Masaki-Kato Masao, moves 112 to 116

In this example white adds some valueable stones to his framework before making life with . If black tries to kill, white gets out using snapback. --ekberg

[1] "life for the corner" is not a gain

aLegendWai: As you said in the previous diagram, W can live by playing either "a" and "b". So I feel W is alive already.

TDerz: White would be dead after .
So the initial statement above could be rephrased "White plays kikashi before living with with either a or b."

kevinwm: Here's another way to think of it: w needs to move in order to live (eye space is a bulky-5). But instead, white can play a move that makes miai for life, by adding a new opportunity to make an eye. This is superior, because 1) b should respond now, rather than letting w live in sente, and 2) it threatens to make life with extra points. Given the choice between just living, or guaranteeing life by threatening to make another eye and extending - the latter is always better.

White needs to play

In this case, I don't feel the capture of 2 stones yields the gain of "life for the corner". W is already alive, so this gain is not a gain at all. Rather "the capture of 2 stones" saves 1 stone at "a".

What do you think?

Rich: What happens if black plays b first? The point is, W must play to live.

aLegendWai: But in the diagram, W plays first. If the above is going to compare the difference between playing elsewhere or not, my humble opinion is it will be a valid point.

[2]

This move is worth 10/11 points (deiri counting)

aLegendWai: Try to compare 2 cases.

If B responds
If B plays elsewhere

W doesn't need to play at "a" and "b". W gains 2 more points.
W captured 2 . It gets 4 points (2 prisoner + 2 territories).
B has to play , . B loses 2 points.
There is an endgame move at "c,d,e". B has already lost 2 points at "c/d". And the endgame values 1-point. If W plays first, B will lose 1 more point.
By the way, B always gets sente in this endgame if both parties completes the endgame.

Thus the value of playing is 10(+1) points.

Any idea is welcome.

Bill:

Setting yourself up as an authority again.

This is probably the last time I am going to say that.

[3]

Gain of capturing 2

aLegendWai: Here is what I feel about the gain of capturing 2 :

• This move is worth 10/11 points (Click on [2] for details)
• It eliminates some potential ko threat
• It creates some minor weaknesses to B

Comment

Comment: Depending on the situation, if White plays at alone, then later the peep at may turn out useful. --unkx80

Alex Weldon: I'm moving a section of the conversation here to Do Not Peep at Cutting Points/Discussion, as it has little to do with "play kikashi before living."