Before living with , White makes a kikashi with . This is an example of the proverb play kikashi before living. This serves as a peep at the Black's tiger shape, forcing Black to answer at . It also has a local achievement too: by connecting the stone in sente, it enhances the strength of the White wall. As is part of the White's wall, the proverb on sacrificing kikashi stones does not apply in this example.
Later, the peep at is another typical example of a kikashi. Due to his marked tiger shape, White is already connected, and there is hardly any aji left in this position. So Black's move is justified: he forces White to confirm the choice she already made: connect her stones.
does several things at a time: it destroys some eye shape, and it can serve as a ladder breaker later, or be a stone that is just in the right spot to win a capturing race. But is a stone to be treated lightly. It is not an important stone. It is a kikashi stone.
The point of is not to make white play at . The point of playing there is that it might become useful in the future, and it is the fact that forces white to play at which enables black to play at without losing sente.
Later in the game White starts to play against the marked kikashi stones but both players treat them lightly. With Black is willing to let White cut off the two stones. However, shows that White has no interest in such a small-scale capture.
In this position, Black has a few forcing moves. He starts off with . If unanswered, White's position would completely crumble. then forces White to take the two stones. White may decide (but is unlikely) to abandon her three stones, depending on the rest of the top side. Next, forces once more to effectively take the stones off the board. Next, Black can play along the left side or connect around a.
and are mere sente moves, moves that are played to keep the initiative while building the position. is the only example of kikashi, because the stone is treated as disposable:
Later, close to the endgame, this may be played. The added value of is that it makes sente again, compared to if Black had not forced White to capture as in the previous diagram.
In a game vs. Yamashita Keigo in the 29th Meijin league, Cho Chikun plays kikashi with - before strengthening his center group with . (See commentary at http://www.asahi.com/igo/meijin29/16/05.html.)
Despite the proverb about sacrificing kikashi stones, only is in any danger.
The commentary says, 右辺を白70から76と利かし . White plays kikashi on the right side with - .
These plays are more urgent because of White's running group. After White secures the group, they might not be so urgent.
is a peep. Black can sacrifice with b and d after White a.
From Charles Matthews - Shape Up! (p.48)
What is inside: 1. Kikashi ofcourse. 2. Shape, one way to use the Big Bulge and how to set it up. 3. Double purpose move. Not only in sense of the normal meaning of double purpose move. More in sense of the time changing purpose. First is needed to get in the right place. Later it will treated lightly to get a strong position. If W tenuki playing elsewhere is needed to cut. So this is another use of the Big Bulge here. Of course W tenuki is in this situation not the best idea, but this shows the dynamic of this shape. I will call it: A bunch of virtual live lines. In the moment where is played all they exist, but only one get reality later (condensation). Therefore fixing a position reduce the value. From this point of view a good shape is a configuration which has enough nice future prospects to a brought variety of possible upcoming situations. A good feeling means than to look somehow in the future knowing which live lines from different possible shapes over the goban will work later nicely together. This maybe is also called luck, I guess. QWerner
Tapir: To my limited understanding it is far from clear whether will turn out as kikashi. Imagine the Black stone on the right () needs to make eyes later, by disabling the attachment at k might as well turn out to be aji keshi.
Here is an example of a position where analysis with LeelaZero points to the existence of a forcing move
As pointed out by Go Seigen, Black really wants to approach at , as a counterexample of approach from the wider side. However ...
is a forcing move, committing White to a locally optimal play. forces White to connect at (something she could have done at already) and now helps and .
If Black plays after approaching the corner, White can pincer at and sacrifice the stones on the side in favor of an attack on and .