Edge template IV3b
From HexWiki
Template IV3-b is a 4th row edge template with 3 stones.
The shaded cell is not part of the template and can be occupied by Blue.
If the middle red piece is removed, the template stays valid, as long as the two remaining stones are connected to each other in some other way.
(mirror-image is from www.drking.org.uk)
Defending the template
Red has this threat:
For trying to block the connection Blue has to play on the 5 cells used by that threat.
If Blue moves in any of the 3 cells marked x, Red has the same response:
Red 4 is connected to the bottom by template III2-e.
If Blue moves at y:
Red 2 is a ladder escape for the ladder formed by Red 6.
If Blue moves at z:
Red 4 is connected to the top by double threat at the two cells marked "+".