I've tried to understand this feature in my
german AAR/tutorial. As you can see by looking at the pictures and as my experience tells me, my explanation is certainly not 100% correct. We'd need an insider to give us certainty.
Zone of control points
All elements in a region produce "zone of control"-points in amount of their "patrol"-values. So, for example, a unit that consists of 5 elements (each with a patrol value of 5) produces 25 "zone of control"-points. In order to get your total zone of control points in a region, you have to add all the zone of control points produced by your elements and then add the control points produced by fortifications (if there is one in the region) according to this formula:
(level of fortification) x (your military control in the region) = zone of control points
Evasion value
Each stack has an evasion value, which corresponds to the
average "evasion"-value of all the elements of the stack. For example, a stack that consits of light cavalry (evasion 9) only will have an evasion value of 9. There are also other factors that influence the evasion value: the overall size of the stack, weather and terrain.
Blocked movements
Whenever you want to make a stack
leave a region in which your enemy generates "zone of control"-points (by means of troops and/or a controled fortification), the "zone of control"-points of the enemy are divided by the "evasion"-value of your stack. Your stack will only be allowed to leave the region if your military control in your destination-region is at least equal the result of this division.
You can always check what regions your stack will be allowed to enter by howering your cursor over the small bulls-eye-sign.
