Triangles are one of the most powerful formations in Stymie. They are flexible defensively and can launch attacks in multiple directions from several angles.
In figure 1, it is Silver’s turn and he has a few pretty good options. E1 is open and bringing a stone into play is always worth considering. Gold already has 3 of his stones on Prime spaces though. and his pieces on D5, D7, E4 and E6 are on the verge of being brought together and taking control of the board.
In Figure 2 Silver moves the Stone on A4 to A5 creating a triangle with the stones on A5, A6, and B5. Suddenly Gold is facing threats from 2 different angles. If Gold doesn’t find a way to counter the looming attack, his force could be decimated.
In Figure 3 Gold counters Silver’s attack by moving his stone on E6 to E5 and forming a triangle of his own. If Silver choses to capture the Gold stones on B7 and D7, Gold can answer back by capturing the stones on B5 and A6 or he could take control of the Antipode and capture the Silver stone on C2.
If you take some time to play through possible moves for each player, you can get an idea of how quickly the board can change and how powerful it is to have initiative.