Contact play, diagonal away

Otake's play  

In a 1995 game against Yu Bin, Otake Hideo played the highly-unusual after the contact play .

This is not joseki: Black was very strong on the upper side and wanted sente to play at a and complete his formation.

Continuation  

These plays followed.

Answering the contact play  

On general principles of shape, one expects Black at answer at a, b or c (the play at the marked point being bad shape).

Exactly this shape does occur in a number of tenuki joseki; for example

• 3-4 point high approach two-space high pincer, ogeima, tenuki
• 4-5 point 4-3 approach ogeima, tenuki.

Charles Matthews