One of the most important aspects of being able to play COH well is knowing when and where to fight. One of the most common mistakes I saw as a mentor in COH was players overextending themselves early on.
This usually meant that they would be beaten back and have the tide turned against them very quickly in the game.
At the same time, I also see players gain advantages and simply let them go because they either didn’t know they had the upper hand, or didn’t know how to exploit it properly. I think the root of these problems comes from not understanding what areas in the map to fight on early in the game. Click the image to enlarge it:
Here is a screenshot of Angoville that I have modified with Paint. You can see many boxes with 5 different colors. These represent the advisability of fighting in different areas of the map from the perspective of the northern player.
Blue areas represent excellent places to fight, they are near his base so units he is making from his base will join the fight sooner, along with any units that may have retreated and are coming back reinforced.
Green areas have the same qualities as the blue ones, but to a lesser extent.
Yellow zones represent an area where either player does not have an advantage by nature of his base being closer to the area being contested. To gain an advantage in the yellow zone, cover, buildings, and formation must be used.
Red zones represent areas that the northern player should not fight over unless he already he has a large advantage.
For Angoville, however there is an exception. A player that has captured the houses on the right hand side of the map can use those as a large force multiplier and can overextend himself more as long as he keeps control of the houses.
Black zones represent areas immediately outside his opponent’s base, and should not be pushed until later on in the game unless a very large advantage has been gained.