How should one start a game of Syrtis? One idea is to eliminate enemy territory--in other words, to sink tiles that have the opponent's shape and color.
If I am playing as Light (controlling the light, round towers), my towers will never occupy a dark, square tile. And I know those tiles will be valuable to my opponent, since dark towers on those tiles will occupy both a dark island and a square island. That means they will tend to have more movement options. So why not start the game by sinking some vulnerable pieces of enemy territory?
It's a good idea. Up to a point.
A danger to be wary of is that by sinking too many enemy tiles you will make it easier for your opponent to form a complete island. When I sink a dark, square tile, with one action I leave fewer dark tiles and fewer square tiles on the board. All else being equal, that makes forming a dark island or a square island less difficult.
Usually all else is not equal, and the benefits are well worth it. But sometimes it comes with an unacceptable risk. That's especially so when the tile you sink is isolated from other enemy tiles, and when your opponent is already approaching a complete island.
For example, take the opening position at left. In this game, Light has the first move. If Light blindly follows the policy of sinking enemy territory at the beginning of the game, it quickly leads to trouble. Light sinks the low-hanging fruit at c1, and Dark sinks at c4. Then Light sinks again at e4 and immediately learns to regret it. (Do you see why? You'll find the solution on the easy puzzles page.)
Light should have seen the enormous square island in the upper right of the board as a red flag. In some positions it possible (even early in the game!) to lose by sinking enemy territory.
That suggests another strategic idea, one that is useful not only in the opening but throughout the game: holding territory hostage. More on that in posts to come.