A play that creates an open tria in the middle of the L shape forms the h shape. The h shape is powerful because when it's been formed the opponent must immediately respond to the open tria threat. This begins actively using the potential for threats that began with the I shape and gives the first player initiative. From the h shape a player can immediately form three other open trias. One of open trias available forms the X shape. If the opponent fails to stop this from happening they'll lose the game by allowing the attacking player to form an unstoppable open tessera.