Diagonal attachment - knight's move angle play sabaki technique

As old as the hills  

This technique employed by White to avoid the standard shape (White at a) goes back at least to the time of Dosaku. Black has a choice of ways to cut. Clearly here Black's cut at a will be met by White b and then there is an important ladder.

Empty triangle cut  

After Black and White seems to have problems, but her resources are White a to escape, and the hane plays b or c to attack Black's current shortage of liberties caused by the empty triangle. This occurred in a game Dong Yan-Lin Feng 2002-05-13 in China. White at is a quieter way to play here.

Hashimoto-Fujisawa  

This is from Hashimoto Utaro-Fujisawa Kuranosuke 1955-03-24. With a bad ladder, White opts to play and as a dodging tactic. You could classify this as simple light play, perhaps. Black at is equally popular in this tenuki pincer joseki.

Charles Matthews