Difference between revisions of "Trapezoid"
(Minor formatting; added "trapezoid" as alternate name for this template.) |
(Converted to new hexboard diagrams, and added missing material on dominated moves in the trapezoid) |
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| Line 1: | Line 1: | ||
| − | The '''mouth''' or '''trapezoid''' is | + | The '''mouth''' or '''trapezoid''' is an [[interior template]] with a wide base. It is one of the most common interior templates after the [[bridge]]. The [[carrier]] of the template, i.e., the set of cells that must be empty for the template to be valid, is shown in the following diagram. |
| − | < | + | <hexboard size="3x3" |
| − | + | coords="none" | |
| − | + | edges="none" | |
| − | + | visible="-a1" | |
| − | + | contents="R a3 b1 c1 c3" | |
| − | + | /> | |
| − | + | ||
== Common patterns == | == Common patterns == | ||
| Line 13: | Line 12: | ||
=== Gaining Ground === | === Gaining Ground === | ||
The mouth can be used to steal [[territory]]. For example, in the following situation | The mouth can be used to steal [[territory]]. For example, in the following situation | ||
| − | < | + | <hexboard size="6x7" |
| + | coords="none" | ||
| + | edges="bottom right" | ||
| + | visible="area(a5,a6,g6,g1,e1)" | ||
| + | contents="R e2 f2 B c4 d5" | ||
| + | /> | ||
Red can play as follows: | Red can play as follows: | ||
| − | < | + | <hexboard size="6x7" |
| − | + | coords="none" | |
| + | edges="bottom right" | ||
| + | visible="area(a5,a6,g6,g1,e1)" | ||
| + | contents="R e2 f2 B c4 d5 R 1:d4 B 2:c5 R 3:f4" | ||
| + | /> | ||
=== Ladder Escapes === | === Ladder Escapes === | ||
The mouth also allows some [[ladder escape]] constructions. | The mouth also allows some [[ladder escape]] constructions. | ||
| − | < | + | <hexboard size="6x11" |
| + | coords="none" | ||
| + | edges="bottom" | ||
| + | visible="area(e1,c3,a6,g6,h5,j1)" | ||
| + | contents="R e2 f2 h4 B h5 g5 R 1:g4 B 2:f5 R 3:f4 B 4:e5 R 5:d4" | ||
| + | /> | ||
== Dominated cells == | == Dominated cells == | ||
| − | |||
| − | + | If Blue wants to intrude into the trapezoid, the only possible intrusion point is the hex marked "*". | |
| + | <hexboard size="3x3" | ||
| + | coords="none" | ||
| + | edges="none" | ||
| + | visible="-a1" | ||
| + | contents="R a3 b1 c1 c3 E *:a2" | ||
| + | /> | ||
| + | Because if Blue plays anywhere else in the trapezoid's carrier, Red can immediately respond at "*", [[dead cell|killing]] Blue's piece. Therefore, from Blue's point of view, "*" [[dominated cell|dominates]] all other possible moves in the trapezoid's carrier. | ||
| + | |||
| + | The same holds from Red's point of view as well. If Red is to play anywhere in the carrier of the trapezoid, the only sensible move is at "*", because this [[captured cell|captures]] the rest of the carrier. | ||
[[category:interior templates]] | [[category:interior templates]] | ||
[[category:basic Strategy]] | [[category:basic Strategy]] | ||
Revision as of 04:37, 7 December 2020
The mouth or trapezoid is an interior template with a wide base. It is one of the most common interior templates after the bridge. The carrier of the template, i.e., the set of cells that must be empty for the template to be valid, is shown in the following diagram.
Common patterns
Gaining Ground
The mouth can be used to steal territory. For example, in the following situation
Red can play as follows:
Ladder Escapes
The mouth also allows some ladder escape constructions.
Dominated cells
If Blue wants to intrude into the trapezoid, the only possible intrusion point is the hex marked "*".
Because if Blue plays anywhere else in the trapezoid's carrier, Red can immediately respond at "*", killing Blue's piece. Therefore, from Blue's point of view, "*" dominates all other possible moves in the trapezoid's carrier.
The same holds from Red's point of view as well. If Red is to play anywhere in the carrier of the trapezoid, the only sensible move is at "*", because this captures the rest of the carrier.
