Bulge Ko
Bulge ko is the term coined by Charles Matthews to describe a ko that is set up with a bulge move.
In this diagram, is a contact play which aims at sabaki. If Black responds with the hane at
, then
is the bulge move. If Black gives atari with
, then
sets up the ko. For White to connect against Black's atari may be slow or heavy. White may aim to enlarge the ko by playing a or b.
The techniques involved in setting up and fighting a bulge ko are relevant to many middle game sequences and corner invasions (for example: 4463Enclosure33Invasion)
For more information see: