Difference between revisions of "Edge template V1b"

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(Some copy-editing.)
(Added "see also", and some copy-editing.)
 
(7 intermediate revisions by 2 users not shown)
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   />
 
   />
  
Now Red is connected by [[Tom's_move#Tom.27s_move_for_3rd-and-5th_row_parallel_ladders|Tom's move for 3rd and 5th row parallel ladders]].
+
Now Red is connected by [[Tom's move for 3rd and 5th row parallel ladders]].
 
+
Continuation:
+
 
+
<div class="toccolours mw-collapsible  mw-collapsed">
+
 
+
Now Red has two main threats. Via a [[ziggurat]]:
+
 
+
<hexboard size="6x14"
+
  coords="hide"
+
  edges="bottom"
+
  visible="area(f1,a6,n6,n4,l2,h1)"
+
  contents="R e2 d4 d3 B c3 d5 e3 c5 R 1:g3 E *:f4 S f2 g2 f3 e4 area(d6,f4,g4,g6)"
+
  />
+
And via [[edge template IV2b]]:
+
<hexboard size="6x14"
+
  coords="hide"
+
  edges="bottom"
+
  visible="area(f1,a6,n6,n4,l2,h1)"
+
  contents="R e2 d4 d3 B c3 d5 e3 c5 R 1:g3 E *:f4 S f2 g2 f3 e4 area(e6,i6,i4,h3,f4)"
+
  />
+
 
+
Blue must play in the overlap:
+
<hexboard size="6x14"
+
  coords="hide"
+
  edges="bottom"
+
  visible="area(f1,a6,n6,n4,l2,h1)"
+
  contents="R e2 d4 d3 B c3 d5 e3 c5 R 1:g3 S f2 g2 f3 e4 area(e6,f4,g4,g6)
+
            E p:f2 q:g2 r:f3 s:e4 t:f4 u:g4 v:f5 w:g5 x:e6 y:f6 z:g6"
+
  />
+
 
+
 
+
==== Intrusion at p, q, r ====
+
 
+
<hexboard size="6x14"
+
  coords="hide"
+
  edges="bottom"
+
  visible="area(f1,a6,n6,n4,l2,h1)"
+
  contents="R e2 d4 d3 B c3 d5 e3 c5 R 1:g3 B 2:(f3 f2 g2) R 3:e4 S d6 e5 e6"
+
  />
+
 
+
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 [[Edge_template_IV2b|IV-2-b]]. ​ Otherwise, Red connects via [[Tom's move]].
+
 
+
<hexboard size="6x14"
+
  coords="hide"
+
  edges="bottom"
+
  visible="area(f1,a6,n6,n4,l2,h1)"
+
  contents="R e2 d4 d3 B c3 d5 e3 c5 R 1:g3 B 2:(f3 f2 g2) R 3:e4 5:e5 7:f5 9:i4 B 2:(f3 f2 g2) 4:e6 6:d6 8:f6"
+
  />
+
 
+
==== Intrusion at s ====
+
 
+
<hexboard size="6x14"
+
  coords="hide"
+
  edges="bottom"
+
  visible="area(f1,a6,n6,n4,l2,h1)"
+
  contents="R e2 d4 d3 B c3 d5 e3 c5 R 1:g3 B 2:e4 R 3:f2"
+
  />
+
 
+
Red is connected by [[edge template IV1d]].
+
 
+
==== Intrusion at t ====
+
 
+
<hexboard size="6x14"
+
  coords="hide"
+
  edges="bottom"
+
  visible="area(f1,a6,n6,n4,l2,h1)"
+
  contents="R e2 d4 d3 B c3 d5 e3 c5 R 1:g3 B 2:f4 R 3:e4 B 4:e5 R 5:h2"
+
  />
+
 
+
Now Red is connected by [[Fifth_row_edge_templates#V-2-m|edge template V2m]]. If Blue plays 4 on the first row instead, Red connects by [[Tom's move]]:
+
<hexboard size="6x14"
+
  coords="hide"
+
  edges="bottom"
+
  visible="area(f1,a6,n6,n4,l2,h1)"
+
  contents="R e2 d4 d3 B c3 d5 e3 c5 R 1:g3 B 2:f4 R 3:e4 B 4:e6 R 5:e5 B 6:d6 R 7:f5 B 8:f6 R 9:i4"
+
  />
+
 
+
==== Intrusion at u ====
+
 
+
<hexboard size="6x14"
+
  coords="hide"
+
  edges="bottom"
+
  visible="area(f1,a6,n6,n4,l2,h1)"
+
  contents="R e2 d4 d3 B c3 d5 e3 c5 R 1:g3 B 2:g4 R 3:f4 B 4:e6 R 5:f5 B 6:f6 R 7:i4"
+
  />
+
Red is connected by [[Tom's move]].
+
 
+
==== Intrusion at v ====
+
 
+
<hexboard size="6x14"
+
  coords="hide"
+
  edges="bottom"
+
  visible="area(f1,a6,n6,n4,l2,h1)"
+
  contents="R e2 d4 d3 B c3 d5 e3 c5 R 1:g3 B 2:f5 R 3:f4 E *:e5 *:h4"
+
  />
+
Red is connected by [[double threat]].
+
 
+
==== Intrusion at w ====
+
 
+
Red responds with
+
 
+
<hexboard size="6x14"
+
  coords="hide"
+
  edges="bottom"
+
  visible="area(f1,a6,n6,n4,l2,h1)"
+
  contents="R e2 d4 d3 B c3 d5 e3 c5 R 1:g3 B 2:g5 R 3:i4 S red:area(i4,g6,j6,j4)"
+
  />
+
 
+
Continuation:
+
<div class="toccolours mw-collapsible  mw-collapsed">
+
 
+
We will assume that Red simply defends the pink [[ziggurat]], and therefore we will not need to consider any Blue intrusions there.
+
 
+
Red's main threats are
+
 
+
<hexboard size="6x14"
+
  coords="hide"
+
  edges="bottom"
+
  visible="area(f1,a6,n6,n4,l2,h1)"
+
  contents="R e2 d4 d3 B c3 d5 e3 c5 R 1:g3 3:i4 5:e4 B 2:g5 S d6 e6 e5 e4 f4 f3 h3 h4 i3 S red:area(i4,g6,j6,j4)"
+
  />
+
 
+
and
+
 
+
<hexboard size="6x14"
+
  coords="hide"
+
  edges="bottom"
+
  visible="area(f1,a6,n6,n4,l2,h1)"
+
  contents="R e2 d4 d3 B c3 d5 e3 c5 R 1:g3 3:i4 5:f2 B 2:g5 S f2 g2 e6 f6 f5 f4 g4 f3 h3 h4 i3 S red:area(i4,g6,j6,j4)"
+
  />
+
 
+
Blue [[mustplay region|must play]] in the overlap:
+
 
+
<hexboard size="6x14"
+
  coords="hide"
+
  edges="bottom"
+
  visible="area(f1,a6,n6,n4,l2,h1)"
+
  contents="R e2 d4 d3 B c3 d5 e3 c5 R 1:g3 3:i4 B 2:g5 S e6 f4 f3 h3 h4 i3 E c:e6 b:f4 a:f3 d:h3 f:h4 e:i3 S red:area(i4,g6,j6,j4)"
+
  />
+
 
+
If Blue plays at a, then Red plays 5, after which Red connects via
+
 
+
<hexboard size="6x14"
+
  coords="hide"
+
  edges="bottom"
+
  visible="area(f1,a6,n6,n4,l2,h1)"
+
  contents="R e2 d4 d3 B c3 d5 e3 c5 R 1:g3 3:i4 5:e4 7:f4 B 2:g5 4:f3 6:e5 6:d6 E *:f5 *:h3 S red:area(i4,g6,j6,j4)"
+
  />
+
 
+
or
+
 
+
<hexboard size="6x14"
+
  coords="hide"
+
  edges="bottom"
+
  visible="area(f1,a6,n6,n4,l2,h1)"
+
  contents="R e2 d4 d3 B c3 d5 e3 c5 R 1:g3 3:i4 5:e4 7:e5 9:f5 11:h3 B 2:g5 4:f3 6:e6 8:d6 10:f6 S red:area(i4,g6,j6,j4)"
+
  />
+
 
+
If Blue plays at c, then Red responds with
+
 
+
<hexboard size="6x14"
+
  coords="hide"
+
  edges="bottom"
+
  visible="area(f1,a6,n6,n4,l2,h1)"
+
  contents="R e2 d4 d3 B c3 d5 e3 c5 R 1:g3 3:i4 5:h3 B 2:g5 4:e6 S red:area(i4,g6,j6,j4)"
+
  />
+
 
+
This forces Blue to defend towards the top, after which
+
 
+
<hexboard size="6x14"
+
  coords="hide"
+
  edges="bottom"
+
  visible="area(f1,a6,n6,n4,l2,h1)"
+
  contents="R e2 d4 d3 B c3 d5 e3 c5 R 1:g3 3:i4 5:h3 7:e4 B 2:g5 4:e6 6:(f2 f3 g2) S red:area(i4,g6,j6,j4)"
+
  />
+
 
+
connects directly or via red 1.
+
 
+
<hexboard size="6x14"
+
  coords="hide"
+
  edges="bottom"
+
  visible="area(f1,a6,n6,n4,l2,h1)"
+
  contents="R e2 d4 d3 B c3 d5 e3 c5 R 1:g3 3:i4 5:h3 7:e4 9:e5 11:f5 B 2:g5 4:e6 6:(f2 f3 g2) 8:f4 10:d6 S red:area(i4,g6,j6,j4)"
+
  />
+
 
+
If Blue plays at b, then Red
+
 
+
<b>to be completed</b>
+
</div>
+
 
+
==== Intrusion at x ====
+
 
+
Red can respond here:
+
 
+
<hexboard size="6x14"
+
  coords="hide"
+
  edges="bottom"
+
  visible="area(f1,a6,n6,n4,l2,h1)"
+
  contents="R e2 d4 d3 B c3 d5 e3 c5 R 1:g3 R 3:f5 B 2:e6"
+
  />
+
 
+
Continuation:
+
<div class="toccolours mw-collapsible  mw-collapsed">
+
 
+
Red has several threats. Via [[double threat]]s:
+
 
+
<hexboard size="6x14"
+
  coords="hide"
+
  edges="bottom"
+
  visible="area(f1,a6,n6,n4,l2,h1)"
+
  contents="R e2 R g3 R d4 B c5 B d5 E *:e5 R f5 B e6 e3 R d3 S area(f2,d6,f6,g4,g2)-e6"
+
  />
+
 
+
Via [[double threat]] and [[edge template III2b]]:
+
 
+
<hexboard size="6x14"
+
  coords="hide"
+
  edges="bottom"
+
  visible="area(f1,a6,n6,n4,l2,h1)"
+
  contents="R e2 S f2 g2 f3 R g3 R d4 S e4 f4 E *:g4 S h4 B c5 B d5 S e5 R f5 S g5 S h5 B e6 S f6 g6 h6 B e3 R d3 S g3 g4 f5"
+
  />
+
 
+
Via [[bridge]]s and [[Tom's move]]:
+
 
+
<hexboard size="6x14"
+
  coords="hide"
+
  edges="bottom"
+
  visible="area(f1,a6,n6,n4,l2,h1)"
+
  contents="R e2 R g3 R d4 B c5 B d5 R f5 B e6 B e3 R d3 E *:f2 S area(f2,f6,l6,l4,j2)"
+
  />
+
 
+
Via a [[wheel]] and [[Tom's move]]:
+
 
+
<hexboard size="6x14"
+
  coords="hide"
+
  edges="bottom"
+
  visible="area(f1,a6,n6,n4,l2,h1)"
+
  contents="R e2 R g3 R d4 B c5 B d5 R f5 B e6 B e3 R d3 E *:e4 S area(f3,e4,e5,f6,l6,l4,j2,h2)"
+
  />
+
 
+
Via a [[double threat]] and [[Tom's move]]:
+
 
+
<hexboard size="6x14"
+
  coords="hide"
+
  edges="bottom"
+
  visible="area(f1,a6,n6,n4,l2,h1)"
+
  contents="R e2 R g3 R d4 B c5 B d5 R f5 B e6 B e3 R d3 E *:f4 S area(f2,f6,l6,l4,j2)+e4-g4"
+
  />
+
 
+
Via a different [[double threat]] and [[Tom's move]]:
+
 
+
<hexboard size="6x14"
+
  coords="hide"
+
  edges="bottom"
+
  visible="area(f1,a6,n6,n4,l2,h1)"
+
  contents="R e2 R g3 R d4 B c5 B d5 R f5 B e6 B e3 R d3 E *:e5 S area(f2,f6,l6,l4,j2)+e4+e5+d6-f6"
+
  />
+
 
+
 
+
Blue [[mustplay region|must play]] in the overlap:
+
 
+
<hexboard size="6x14"
+
  coords="hide"
+
  edges="bottom"
+
  visible="area(f1,a6,n6,n4,l2,h1)"
+
  contents="R e2 R g3 R d4 B c5 B d5 R f5 B e6 B e3 R d3 S f3 f4 E r:f3 t:f4"
+
  />
+
 
+
If Blue plays at r:
+
 
+
<hexboard size="6x14"
+
  coords="hide"
+
  edges="bottom"
+
  visible="area(f1,a6,n6,n4,l2,h1)"
+
  contents="R e2 R g3 R d4 B c5 B d5 R f5 B e6 B e3 R d3 B 1:f3 R 2:e4"
+
  />
+
 
+
And then, depending on Blue's next move, either a [[crescent]]
+
 
+
<hexboard size="6x14"
+
  coords="hide"
+
  edges="bottom"
+
  visible="area(f1,a6,n6,n4,l2,h1)"
+
  contents="R e2 R g3 R d4 B c5 B d5 R f5 B e6 B e3 R d3 B 1:f3 R 2:e4 B 3:e5 R 4:f4 B 5:f6 R 6:h5"
+
  />
+
 
+
or [[Tom's move]]:
+
 
+
<hexboard size="6x14"
+
  coords="hide"
+
  edges="bottom"
+
  visible="area(f1,a6,n6,n4,l2,h1)"
+
  contents="R e2 R g3 R d4 B c5 B d5 R f5 B e6 B e3 R d3 B 1:f3 R 2:e4 B 3:f6 R 4:e5 B 5:d6 R 6:i4"
+
  />
+
 
+
If Blue plays at t:
+
 
+
<hexboard size="6x14"
+
  coords="hide"
+
  edges="bottom"
+
  visible="area(f1,a6,n6,n4,l2,h1)"
+
  contents="R e2 R g3 R d4 B c5 B d5 R f5 B e6 B e3 R d3 B 1:f4 R 2:e4 E a:e5 b:d6 c:f6"
+
  />
+
 
+
If Blue plays at b or c, Red plays at a and connects via [[Tom's move]]. If Blue plays at a:
+
 
+
<hexboard size="6x14"
+
  coords="hide"
+
  edges="bottom"
+
  visible="area(f1,a6,n6,n4,l2,h1)"
+
  contents="R e2 R g3 R d4 B c5 B d5 R f5 B e6 B e3 R d3 B 1:f4 R 2:e4 B 3:e5 R 4:h2"
+
  />
+
 
+
Now Red is connected left by [[double threat]], and right by a [[Theorems_about_templates#Corner_clipping|clipped]] version of [[Fifth_row_edge_templates#V-2-m|edge template V2m]].
+
 
+
</div>
+
 
+
==== Intrusion at y ====
+
 
+
<hexboard size="6x14"
+
  coords="hide"
+
  edges="bottom"
+
  visible="area(f1,a6,n6,n4,l2,h1)"
+
  contents="R e2 B e3 R d3 R 1:g3 R d4 B c5 B d5 B 2:f6 R 3:e5 E *:d6 *:e6 B 4:e4 R 5:f2"
+
  />
+
Note that the hexes marked "*" are [[captured cell|captured]] by Red 3, so Blue 4 is forced. Then Red is connected by [[edge template IV2e]].
+
 
+
==== Intrusion at z ====
+
 
+
<hexboard size="6x14"
+
  coords="hide"
+
  edges="bottom"
+
  visible="area(f1,a6,n6,n4,l2,h1)"
+
  contents="R e2 B e3 R d3 R 1:g3 R d4 B c5 B d5 B 2:g6 R 3:e5 E *:d6 *:e6 B 4:e4 R 5:f2"
+
  />
+
Note that the hexes marked "*" are [[captured cell|captured]] by Red 3, so Blue 4 is forced. Then Red is connected by [[Fourth_row_edge_templates#IV-2-q|edge template IV2p]].
+
 
+
</div>
+
  
 
=== Continuation after 2nd row ladder ===
 
=== Continuation after 2nd row ladder ===
Line 459: Line 121:
 
Now Red connects in essentially the same way as [[Tom's move]].
 
Now Red connects in essentially the same way as [[Tom's move]].
  
Continuation:
+
Specifically, Red has these threats:
<div class="toccolours mw-collapsible  mw-collapsed">
+
 
+
Red has these threats:
+
  
 
<hexboard size="6x14"
 
<hexboard size="6x14"
Line 485: Line 144:
 
   />
 
   />
 
    
 
    
The overlap in which Blue must play is:
+
The overlap in which Blue [[mustplay region|must play]] is:
  
 
<hexboard size="6x14"
 
<hexboard size="6x14"
Line 516: Line 175:
 
Note that Red 4 connects to the bottom with [[Edge_template_IV2b|IV-2-b]].
 
Note that Red 4 connects to the bottom with [[Edge_template_IV2b|IV-2-b]].
  
</div>
+
== See also ==
  
 +
* [[Tom's move]]
 +
* [[Tom's move for 3rd and 5th row parallel ladders]]
 +
* [[Fourth row edge templates]]
  
 
[[category:edge templates]]
 
[[category:edge templates]]

Latest revision as of 20:44, 26 July 2022

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

Reduction

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:

abc

Intrusion at a

If Blue intrudes at a, Red can start by forcing a 3rd or 2nd row ladder like this

21435

or like this:

214368579

Red's continuation will be discussed below.

Intrusion at b

If Blue intrudes at b, Red can start by forcing a 3rd row ladder like this:

43251

Red's continuation will be discussed below.

Intrusion at c

If Blue intrudes at c, Red can start by forcing a 2nd row ladder like this:

4325671

Red's continuation will be discussed below.

Continuation after 3rd row ladder

If Red achieved a 3rd row ladder after intrusions a or b as shown above, Red continues as follows.

1

Now Red is connected by Tom's move for 3rd and 5th row parallel ladders.

Continuation after 2nd row ladder

If Red achieved a 2nd row ladder after intrusions a or c above, Red continues as follows.

312

Now Red connects in essentially the same way as Tom's move.

Specifically, Red has these threats:

13524
132
1

The overlap in which Blue must play is:

Four of these five possible moves can be analysed together. In the following diagram, assume Blue has played 1 in any one of the cells marked with +:

64532

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:

76108495213

Note that Red 4 connects to the bottom with IV-2-b.

See also