Loose connection
There are two different types of loose connections, both of which are described below.
Type I
The pieces on this board are able to connect to each other through a bridge by placing a piece on either b1 och b2, that is if they're not prevented to do so.
The two stars on this board shows which positions can be used to break the threat of a loose connection:
These are the same places at which the horizontal player wants to place additional pieces in order to connect the blue pieces.
Type II
This connection is a bit weaker than Type I.
The blue player threatens to connect the pieces by either playing c1 or b3:
which form two bridges between the original pieces.
The obvious way for the red player to stop the blue is to play either b2 or c2:
This is a reasonable defense because either of the two moves (b2 or c2) will block potential bridge connections using either c1 or b3 (only one example shown):