Template VI1/Intrusion on the 4th row

This page is devoted to details on how to defend against intrusions in template VI. This page explores Red's possibilities to defend the template when Blue intrudes on the 4th row.

Red should move here (or the equivalent mirror-image move at "+"):

Now the shaded area is a ladder creation template, giving Red at least a 3rd row ladder as indicated.

Red can escape both 2nd and 3rd row ladders using a ladder escape fork via "+". Specifically, Red escapes a third row ladder like this, and is connected by a ziggurat and double threat at "+":

If Blue yields, or Red starts out with a 2nd row ladder, the escape fork works anyway: