Difference between revisions of "Edge template IV2j"

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The template:
+
Template IV2-j is a 4th row [[edge template]] with 2 stones.
  
<hexboard size="4x5"
+
<hexboard size="4x4"
   coords="hide"
+
   coords="hide"  
   contents="E *:a1 E *:b1 E *:c1 R e1 E *:a2 E *:b2 R c2 E *:a3 E *:a4"
+
   edges="bottom"
 +
  visible="-(a1 a2 a3 b1)"
 +
  contents="R :d1 b2"
 
   />
 
   />
 
    
 
    
 +
Red can connect the stone marked "↑" to the edge. Red cannot guarantee to connect the other stone.
 +
 
(From: [http://www.drking.org.uk/hexagons/hex/templates.html www.drking.org.uk])
 
(From: [http://www.drking.org.uk/hexagons/hex/templates.html www.drking.org.uk])
 +
 +
== Defending the template ==
  
 
Red has two threats:
 
Red has two threats:
  
<hexboard size="4x5"
+
<hexboard size="4x4"
   coords="hide"
+
   coords="hide"  
   contents="E *:a1 E *:b1 E *:c1 E +:d1 R e1 E *:a2 E *:b2 R c2 E +:d2 E *:a3 E +:b3 E +:c3 E *:a4 R 1:b4"
+
   edges="bottom"
 +
  visible="-(a1 a2 a3 b1)"
 +
  contents="E +:c1 R ↑:d1 R b2 E +:c2 E +:b3 R A:b3 E +:a4 E +:b4 "
 
   />
 
   />
  
 
and
 
and
  
<hexboard size="4x5"
+
<hexboard size="4x4"
   coords="hide"
+
   coords="hide"  
   contents="E *:a1 E *:b1 E *:c1 R e1 E *:a2 E *:b2 R c2 E +:d2 E +:e2 E *:a3 R 1:d3 E *:a4 E +:c4 E +:d4"
+
   edges="bottom"
 +
  visible="-(a1 a2 a3 b1)"
 +
  contents="R ↑:d1 R b2 E +:c2 E +:d2 R B:c3 E +:b4 E +:c4"
 
   />
 
   />
  
For a blocking attempt Blue has to play on the overlap field:
+
To attempt blocking, Blue must play in one of the two cells where these threats overlap. If Blue plays in upper one of these cells, Red responds as follows:
 +
<hexboard size="4x4"
 +
  coords="hide"
 +
  edges="bottom"
 +
  visible="-(a1 a2 a3 b1)"
 +
  contents="R ↑:d1 b2 2:d2 4:b3 B 1:c2 3:c4 E +:c1 +:c3"
 +
  />
 +
Red 4 is connected to the bottom and also to the top by one of the two fields marked "+".
  
<hexboard size="4x5"
+
If Blue plays in the other overlap, Red responds as follows:
   coords="hide"
+
<hexboard size="4x4"
   contents="E *:a1 E *:b1 E *:c1 E +:d1 R e1 E *:a2 E *:b2 R c2 B 1:d2 R 2:e2 E *:a3 R 4:c3 E +:d3 E *:a4 B 3:d4"
+
   coords="hide"  
 +
   edges="bottom"
 +
  visible="-(a1 a2 a3 b1)"
 +
  contents="R :d1 b2 2:d3 4:b3 B 1:b4 3:d2"
 
   />
 
   />
  
Red 4 is connected to the bottom and also to the top by one of the two fields marked with +.
+
== Cutting off the other stone ==
  
This template has an extraneous hex. The correct template is:
+
As mentioned, this does not give a connection down for the left stone. If Red keeps the right stone
  
<hexboard size="4x5"
+
<hexboard size="4x4"
   coords="hide"
+
   coords="hide"  
   contents="E *:a1 E *:b1 E *:c1 R e1 E *:a2 E *:b2 R c2 E *:a3 E *:b3 E *:a4"
+
   edges="bottom"
   />
+
   visible="-(a1 a2 a3 b1)"
 
+
   contents="R ↑:d1 b2 2:c3 4:d2 B 1:b3 3:c2 5:c1"
The first threat needs to be modified to:
+
<hexboard size="4x5"
+
  coords="hide"
+
   contents="E *:a1 E *:b1 E *:c1 E +:d1 R e1 E *:a2 E *:b2 R c2 E +:d2 E *:a3 E *:b3 E +:c3 E *:a4 R 1:c3 E +:b4 E +:c4  "
+
 
   />
 
   />
  
There are now two overlap points. The response to the first is the same as above. The response to the second is:
+
connected down within the template, then the sequence of Blue cutting off the left stone is shown above.
<hexboard size="4x5"
+
  coords="hide"
+
  contents="E *:a1 E *:b1 E *:c1 R e1 E *:a2 E *:b2 R c2 E *:a3 E *:b3 E *:a4 B 1:c4 R 2:c3 B 3:b4 R 4:e3"
+
  />
+
  
 
== See also ==
 
== See also ==

Latest revision as of 02:05, 22 September 2021

Template IV2-j is a 4th row edge template with 2 stones.

Red can connect the stone marked "↑" to the edge. Red cannot guarantee to connect the other stone.

(From: www.drking.org.uk)

Defending the template

Red has two threats:

A

and

B

To attempt blocking, Blue must play in one of the two cells where these threats overlap. If Blue plays in upper one of these cells, Red responds as follows:

1243

Red 4 is connected to the bottom and also to the top by one of the two fields marked "+".

If Blue plays in the other overlap, Red responds as follows:

3421

Cutting off the other stone

As mentioned, this does not give a connection down for the left stone. If Red keeps the right stone

53412

connected down within the template, then the sequence of Blue cutting off the left stone is shown above.

See also

Multiple threats