Apex Ko

‘Apex ko’ is a term used by Charles Matthews in article 5 ( Apex Kos) of his series on Setpiece Kos at gobase.org.

It refers to a bulge ko in which the apex is at a 3-3 point, as in this example:

Apex ko  

He studies apex kos in the context of invading a 4-4 point knight's move enclosure.