3-4 point high approach low extension
Keywords: Joseki
This is a Kitani joseki from the 1940s - though not exclusive to him. Black aims to make a very solid stone.
Up to is standard. In this case
leaves no weakness behind (compare with the case of
at a). This is a tight way to play.
Unusually Black can also play inside, as here. In this main line, played in 2001 in a number of pro games, Black takes a larger corner but White is thicker.
3-4 point high approach low extension, trick play
3-4 point high approach low extension, whole board
Question on the variations resulting when black plays 5 as another hane in the last sequence: BQM186