Joseki in Context

Center stretch  

is a stretch towards the center, ceding a large corner to Black.

Joseki produce a fair or even result. This line of play does not split the corner between the two players. Black's gain is clear. White's position must work well from a whole board perspective for this to be playable by White. is a situational play.

Pro game 1

Cho Chikun (W) vs. Ishida Yoshio (1978)  

Cho Chikun uses White's thickness to attack . is a dual purpose move that serves as both a pincer and an extension from the White position in the lower right. This is a common reason to choose this joseki.

Note that if Black cuts at a White can play a ladder with b.

Pro game 2

Takagi Shoichi (W) vs. Takemiya (1986 NHK Cup)  

Takemiya uses - to form a framework on the left side. This is another common reason to choose this joseki.

Note that breaks the ladder, and protects against the cut.

Pro game 3

Otake Hideo (W) vs. Hashimoto Utaro (1976)  

In this case the ladder does not work, and Otake plays . Otake has chosen a miai strategy, carrying a double threat. When Hashimoto prevents a White framework on the left side with - , attacks the stones on the bottom side.

Pro game 4

Sakata vs. Rin Kaiho (1965 Meijin game 4)  

In this game Rin's strategy is quite subtle, related to sente. threatens a pincer, and Sakata protects with . Having kept sente, Rin makes the final enclosure with , getting the last big play of the opening. starts the middle game fighting.

Also, one reason for playing is to keep White from forming a large framework on the top side.

Note: Because reduces Black's influence on the left side, many amateurs would consider it to refute Black's strategy.

Attack  

At the end of the battle on the bottom side, Rin uses his central stones () in the top left to support an attack on White stones () in the top right.

Pro Game 5

Rui Naiwei vs. Jiang Zhujiu (1989)  

Rui's strategy here is also far from obvious. Black's stones in the top left are secure, and the ladder does not work. is a dual purpose play, allowing the ladder while approaching Black's corner. With Jiang secures his weak stones () on the bottom. How can White utilize her stones in the bottom left?

Large framework  

With - , Rui builds a huge central framework.

Desperate invasion  

Through White's valley has become deep. is a desperate invasion. (Black resigned at move 133).