A stretch tria is a shape formed by a single stone placed in line with a pair of stones and a single empty space between them. The stretch tria is vulnerable to counter because an opponent can place a stone between the single stone and the pair and threaten capture. It is powerful however because it threatens to form a tessera, and if unbound on either side forces the opponent to respond in a similar way to open tria, creating initiative and allowing play elsewhere on the board without the opponent interfering. The stretch tria can be a very powerful tool when used in conjunction with other stretch trias. A vertical stretch tria with the pair at the top and the single stone at the bottom can be combined with another stretch tria in a diagonal or horizontal line so that both stretch trias share the same single stone. If an opponent tries to stop one of them, then the very next turn, the player who formed the stretch tria can extend the other and turn it into a tessera. If the tessera is unbound the position is likely a winning one