Edge template V1b is a 5th row edge template with 1 stone.
The validity and minimality of this template has been checked by computer. The template was mentioned on 2016-05-19 by the user shalev in this Little Golem thread, but likely predates that post.
Defense against intrusions
Red has 3 main threats:
using the ziggurat,
using edge template III1b and
using edge_template_IV1d.
For a blocking attempt, Blue must play in the overlap:
Defense against a
Details yet to come...
Defense against b
Red can start like this:
Continuation:
[Expand]
Red has this threat,
so Blue must play in the shaded area.
the top 3 of those cells
Now Blue must play in one of the 3 shaded cells. If Blue plays in the left 2 of those 3, then Red connects via IV-2-b. Otherwise, Red connects via Tom's move.
... 5. e4
Yet to come ...
... 5. f4
Yet to come ...
... 5. g4
Yet to come ...
... 5. e5
Yet to come ...
... 5. f5
Yet to come ...
... 5. g5
Yet to come ...
... 5. d6
The group with 2 is connected to the top in two non-overlapping ways (see area marked with +) and to the bottom with IV-2-b.
... 5. e6
Red can respond here:
Continuation:
[Expand]
Now Red has two threats:
and
Blue has to play on the overlap:
7. f2
7. g2
7. f3
6 is now connected to the left and to the bottom by Tom's move.
7. e4
4 is again connected to the left and to the bottom by Tom's move.
7. f4
Blue has to go on one of the 3 marked fields. However, d6 can't be any better than 35, so it's enough to look at e5 and g6. Let's have a look at g6 first:
4 is now connected to the bottom and to the left in a similar way as in Tom's move. (Just the piece on g3 is connected to the left in a slightly different way.)
The other possible move was e5:
Red 2 is connected to the left by two non-overlapping ways and to the bottom by a 5th row template that has yet to be added to this wiki.
7. g4
Once again 6 is now connected to the bottom and to the left in a similar way as in Tom's move.
7. e5
And Tom's move at the end again.
7. f6
Red 2 is connected to the bottom and to at least one of the red pieces in the middle by Tom's move. Red now has three threats to connect both these pieces to the top:
and
Blue has to play on the overlap:
First move:
Second move:
... 5. f6
Red can start like this:
Red now has these threats:
and
using IV-2-e.
Blue has to play on the overlap:
First move:
You get the the defense against the other move by just swapping 1 and 2 in the diagram above.
... 5. g6
Note that 2 is safely connected to the top, so 3 is forced.
Defense against c
Red has this line:
Blue 3, 5 and 7 are forced.
Continuation:
[Expand]
Red has these threats:
The overlap in which Blue has to play is:
Four of these five possible moves can be analysed in one line. In the following diagram assume Blue has played 1 on any of the fields marked with +:
After Red 2 that group is safely connected to them bottom, now matter which of the pluses Blue chose before.
That leaves only one Blue move to deal with:
Note that Red 4 connects to the bottom with IV-2-b.
