Edge template IV1d
From HexWiki
Template IV1-d is a 4th row edge template with one stone. It also uses some space on the 5th row.
This template was first mentioned by Mike Amling on David King's Hex template page
Defending the template
Red's main threats are:
There is one hex where these threats overlap. Therefore, the only chance for Blue to block Red's connection is to play there.
Development of the remaining case
Now Red is connected by Tom's move.