View source for Edge template IV3a

Template IV3-a is a 4th row [[edge template]] with 3 stones:

<hexboard size="4x5"
   coords="hide"
   edges="bottom"
   visible="-a1--a3 b1 d4 e3 e4"
   contents="E *:a1 E *:b1 R c1 R d1 R e1 E *:a2 E *:a3 E *:e3 E *:d4 E *:e4"
   />

If the middle red piece is removed, the template stays valid, as long as the two remaining stones are connected to each other in some other way.

(From: [http://www.drking.org.uk/hexagons/hex/templates.html www.drking.org.uk])

== Defending the template ==
   
Red has two main threats:

<hexboard size="4x5"
   coords="hide"
   edges="bottom"
   visible="-a1--a3 b1 d4 e3 e4"
   contents="E *:a1 E *:b1 R c1 R d1 R e1 E *:a2 E +:b2 E +:c2 E *:a3 R A:b3 E *:e3 E +:a4 E +:b4 E *:d4 E *:e4"
   />
										
and

<hexboard size="4x5"
   coords="hide"
   edges="bottom"
   visible="-a1--a3 b1 d4 e3 e4"
   contents="E *:a1 E *:b1 R c1 R d1 R e1 E *:a2 E +:c2 E +:d2 E *:a3 R B:c3 E *:e3 E +:b4 E +:c4 E *:d4 E *:e4"
   />
										
For trying to block the connection Blue has to play on the overlap:

<hexboard size="4x5"
   coords="hide"
   edges="bottom"
   visible="-a1--a3 b1 d4 e3 e4"
   contents="E *:a1 E *:b1 R c1 R d1 R e1 E *:a2 E x:c2 E *:a3 E *:e3 E y:b4 E *:d4 E *:e4"
   />

If Blue plays at x:

<hexboard size="4x5"
   coords="hide"
   edges="bottom"
   visible="-a1--a3 b1 d4 e3 e4"
   contents="E *:a1 E *:b1 R c1 R d1 R e1 E *:a2 E +:b2 B 1:c2 E *:a3 R 4:b3 E +:c3 R 2:d3 E *:e3 B 3:c4 E *:d4 E *:e4"
   />

Red 4 is connected to the top by the two cells marked with +.

If Blue plays at y:

<hexboard size="4x5"
   coords="hide"
   edges="bottom"
   visible="-a1--a3 b1 d4 e3 e4"
   contents="E *:a1 E *:b1 R c1 R d1 R e1 E *:a2 E *:a3 R 2:b3 B 5:c3 R 6:d3 E *:e3 B 3:a4 B 1:b4 R 4:c4 E *:d4 E *:e4"
   />

[[category:edge templates]]