Akisankaku

In Go, an empty triangle is a shape where three stones form a triangular structure but leave one point unoccupied. This formation is generally considered inefficient because it reduces liberties and weakens the group’s overall shape. Players are often advised to avoid it, as it can become an easy target for attack.

However, there are situations where an empty triangle is the best available move. For example, it may help secure a connection, disrupt an opponent’s plans, or serve as part of a larger tactical sequence. Recognizing when to avoid or embrace this shape is a skill that reflects a player’s strength and understanding of the game.

On the other hand, when the central point is occupied by an opponent’s stone, the same three stones no longer form an empty triangle — the shape is then efficient and there is nothing wrong with it. Filling the point with your own stone, however, only makes a heavy, overconcentrated clump. This highlights the importance of good shape, a fundamental concept in Go that helps improve efficiency and reduce weaknesses.