Difference between revisions of "Wheel"

From HexWiki
Jump to: navigation, search
(Copy-editing; clarified that empty cells are part of template.)
(Converted to new hexboard diagrams)
Line 1: Line 1:
The '''wheel''' consists of three same-coloured pieces around a central point, along with the four empty cells marked "A" and "B".
+
The '''wheel''' is a 3-stone [[interior template]]. It consists of three same-coloured pieces around a central point, along with the four empty cells marked "A" and "B".
 +
<hexboard size="3x3"
 +
  coords="none"
 +
  edges="none"
 +
  visible="-a1 c3"
 +
  contents="R a3 b1 c2 E B:b2 A:(a2 b3 c1)"
 +
  />
  
[[Image:Wheel.png]]
+
The red pieces are strongly [[Connection|connected]] to each other. [[Blue (player)|Blue]] cannot break the connection between them, and his available forcing moves are not very good. The wheel also has a large circumference, so that it is easy to connect to it from other parts of the board. The drawback is that it requires three pieces and is rather compact, so that it is often not efficient enough to cover a large area.
  
<!--<hex>R5 C5 Vc2 Vd3 Vb4 Sd2 Sb3 Sc4</hex>-->
+
Blue has three possible [[forcing move]]s, labelled A. If Blue plays in one of them, [[Red (player)|Red]] can restore the connection by playing in any of the other cells labelled A. (She can also play at B, but it's usually not as good.) By doing this, Red strengthens her connection, and the influence her pieces have on the rest of the board. It is therefore usually better for Blue not to [[Intrusion|intrude]].
  
The red pieces are strongly [[Connection|connected]] to each other. [[Blue (player)|Blue]] cannot break the connection between them, and his available forcing moves are not very good. It also has a big circumference, so that it is easy to connect to it from other parts of the board. The drawback is that it requires three pieces and is rather compact, so that it is often not efficient enough.
+
Blue should never attempt to intrude by playing at B. Red can then restore the connection between her pieces by playing at any A. Red's position improves, while Blue's piece is not very useful. Although Blue still has to opportunity to intrude in one of the remaining cells marked A, it would have been better for Blue to do this in the first place.
 
+
Blue has three possible [[forcing move]]s, labelled A. If Blue plays in one of them, [[Red (player)|Red]] can restore the connection by playing in any of the other cells labelled A. (He can also play at B, but it's usually not so good.) By doing this, Red strengthens his connection, and the influence his pieces has on the rest of the board. It is therefore usually better for Blue not to [[Intrusion|invade]].
+
 
+
Blue should never attempt to invade by playing at B. Red can then [[Restoring|restore]] the connection between his pieces by playing at any A. Red's position improves, while Blue's piece is useless.
+
  
 
==U-turn==
 
==U-turn==
  
Note that the position below, where Blue has already intruded into one of the starred cells, is a very weak one. In this case, Blue should play at the midpoint, which is now the point where two [[bridge]]s overlap.
+
The wheel should never be confused with the ''U-turn'', shown here:
  
<hex>R5 C5 Vc2 Vd3 Vb4 Hc4</hex>
+
<hexboard size="3x3"
 +
  coords="none"
 +
  edges="none"
 +
  visible="-a1 c3 b3"
 +
  contents="R a3 b1 c2 E B:b2 A:(a2 c1)"
 +
  />
 +
If only two of the cells marked "A" are empty, and not all three of them, it is not a wheel and it is not a template. The U-turn is a very weak position. The U-turn sometimes arises when a player tries to connect via [[bridge]]s and takes a sharp turn. The problem is that  Blue can play at B, leaving Red unable to defend both bridges.
  
 
[[category:interior templates]]
 
[[category:interior templates]]

Revision as of 04:51, 7 December 2020

The wheel is a 3-stone interior template. It consists of three same-coloured pieces around a central point, along with the four empty cells marked "A" and "B".

AABA

The red pieces are strongly connected to each other. Blue cannot break the connection between them, and his available forcing moves are not very good. The wheel also has a large circumference, so that it is easy to connect to it from other parts of the board. The drawback is that it requires three pieces and is rather compact, so that it is often not efficient enough to cover a large area.

Blue has three possible forcing moves, labelled A. If Blue plays in one of them, Red can restore the connection by playing in any of the other cells labelled A. (She can also play at B, but it's usually not as good.) By doing this, Red strengthens her connection, and the influence her pieces have on the rest of the board. It is therefore usually better for Blue not to intrude.

Blue should never attempt to intrude by playing at B. Red can then restore the connection between her pieces by playing at any A. Red's position improves, while Blue's piece is not very useful. Although Blue still has to opportunity to intrude in one of the remaining cells marked A, it would have been better for Blue to do this in the first place.

U-turn

The wheel should never be confused with the U-turn, shown here:

AAB

If only two of the cells marked "A" are empty, and not all three of them, it is not a wheel and it is not a template. The U-turn is a very weak position. The U-turn sometimes arises when a player tries to connect via bridges and takes a sharp turn. The problem is that Blue can play at B, leaving Red unable to defend both bridges.