Boshi

Boshi refers to a move in Go where a stone is placed above an opponent’s stone or group, usually one space away. This move is strategically significant as it can be used to:

• Limit an opponent’s expansion, preventing them from extending outward freely.
• Launch an attack, cutting off potential escape routes for a weak group.
• Reduce an opponent’s framework, making it harder for them to establish secure territory.

The name boshi translates from Japanese as “hat,” illustrating the way the move “covers” an opponent’s stone.

Examples of Boshi

1. Reducing a Moyo
   A player places a boshi move over an opponent’s large framework (moyo), restricting its development and forcing the opponent to defend or settle locally.

2. Attacking a Weak Group
   When an opponent’s group lacks stability, a boshi move can be used to limit its movement, making it more vulnerable to attack.

Mastering boshi allows players to control their opponent’s options, dictate the flow of the game, and create opportunities for both attack and reduction.