4-5 point 4-3 approach inside contact, follow-ups
Assuming White took sente at the end of this joseki, Black gets a chance to attack White.
According to the position as a whole, Black may wish to attack directly at the circle-marked point (a vital point of the diagonal of the
stones); or to build influence with the cover at the square-marked point (discussed at order of play - temptation).
Suppose Black applies the direct approach
. Then the pros usually come out at a. The play at b is a tesuji to help White gain immediate life.
After
here, the inducing move at
is taught as tesuji. It is possible for White simply to play at c'.
![[Diagram]](../../diagrams/41/1e8ae5e485ea8f0a3921b4703fe70d4b.png)
A possible ko
This is from a game Hashimoto Utaro-Suzuki Kensho (B), 1950-01-12. If
here, it makes no sense to go back later to the circled point to play hane, after Black has filled in a liberty. So we get
. Now it can become ko.
There was no actual ko: White sacrificed the
stones and in return weakened
, as a big exchange happened.
Simply playing
here gives White a high position, that is quite thick from fighting perspective. Later White can hope for White a, Black b as forcing.
![[Diagram]](../../diagrams/12/86366052e3fd4b51ddddf2e92fe3bf0a.png)
![[Diagram]](../../diagrams/23/28039cd07b395806b742a73210d25f7e.png)
![[Diagram]](../../diagrams/10/e6c7582dd0a6d127956cc2c7cbe567c8.png)
![[Diagram]](../../diagrams/28/d819d369586544edf7a1256d8cdac8b7.png)
will lead to nothing good for Black.
![[Diagram]](../../diagrams/21/6d951fe84090995263392833c8f861bd.png)
![[Diagram]](../../diagrams/50/d36ea11fd62bda50bedceecd08486552.png)
![[Diagram]](../../diagrams/13/f927f9959e32a1dc932c5890e9a80aec.png)
![[Diagram]](../../diagrams/22/bb751095c65a1f737fca98373421a520.png)
![[Diagram]](../../diagrams/42/26eacd891f5ce16410e9380451390539.png)
2024 the Authors,
published under the ![Sensei's Library [Welcome to Sensei's Library!]](../../images/stone-hello.png)