Suddenly, I realize another aspect of Cricket's brilliance.

I always thought, "You should get some benefit from running away. Otherwise, everyone will fight to the death."

The catch is that retreating and leaving the field are not the same thing. If leaving the field can get you to safety, people will do cheesy things like set a missile cruiser at the edge of the map, fire an alpha strike, and duck off the board if the enemy comes near.

If ships that leave the map are destroyed, the best you can do is get to a safe corner and hope your allies will protect you.

That said, there are still troubling edge effects (assuming that the map doesn't float, because (e.g.) there are 30 asteroids on the table). If the enemy's best attack is to charge to close range, I can prevent him from doing so at full speed by putting my back to a wall.