What is a widening gyre? It's a spiral.
When you begin a new game, based upon the "seed", the map places beginning empires spaced apart. You may be unlucky sometimes as when placed, you have an edge and so less range that the other empires, but of course that means you cannot be attacked from the direction.The Second Coming Launch Audio in a New Window
BY WILLIAM BUTLER YEATS
Turning and turning in the widening gyre
The falcon cannot hear the falconer;
Things fall apart; the centre cannot hold;
Mere anarchy is loosed upon the world,
The blood-dimmed tide is loosed, and everywhere
The ceremony of innocence is drowned;
The best lack all conviction, while the worst
Are full of passionate intensity.
Surely some revelation is at hand;
Surely the Second Coming is at hand.
The Second Coming! Hardly are those words out
When a vast image out of Spiritus Mundi
Troubles my sight: somewhere in sands of the desert
A shape with lion body and the head of a man,
A gaze blank and pitiless as the sun,
Is moving its slow thighs, while all about it
Reel shadows of the indignant desert birds.
The darkness drops again; but now I know
That twenty centuries of stony sleep
Were vexed to nightmare by a rocking cradle,
And what rough beast, its hour come round at last,
Slouches towards Bethlehem to be born?
Having an unassailable defense sounds lucky to me in the long run.
http://www.physics.emory.edu/faculty/we ... sparch.gif
If you begin to build in a widening spiral, then these outer initial sectors become your castle fortfications. Then you estimate from what direction the enemy's or enemies' empire exist and so likely directions of attack.
You build the widening gyre, and then build inward so your newest colonized sectors are protected by the outer perimeter.
If you close the spiral, you have the symbol of Hachiman, a Japanese god of war that the most warlike samurai, the Satsuma, put up as an emblem.
http://mon.xavid.us/Mon/Right%20Three%20Tomoe.svg
If you leave a gap on purpose, then from your "spokes" you send warships that can attack inwardly towards that gap, then close the gap so they are trapped.