I hear people talking a lot about having map control (mostly tzenes). What specifically does a good player consider map control? Is it simply having decent visibility of most of the map so that you know whenever your opponent is moving a force around the map? Or is it having expansions/fighting units around the map? How will I know when I have map control?
So map control is a very ephemeral concept, but at its core is the idea that you can control space (area) on the map and prevent things like: expansions, harassment, scouting.
Since map control is largely concerned with covering area, having map control usually means having units which are very fast and thus can respond quickly. Additionally, it often times means having good vision on most of the map. Its important to note, that Vision helps you maintain map control, but in and of itself it doesn’t give you control. Control is the ability to respond quickly.
Consider the following scenario: You’re a Terran player who went MMM. You have a large force and its sitting in the center of the map.
- How quickly can you respond to Reaper harass?
- If you see Nydus tunnels on opposite sides of the map, what can you do about it?
- What can you do about Overseers contaminating your buildings?
- What’s you’re response to a Void Prism? or Void Ray in the back of your base?
Now compare that player to a Terran player who went 1:1:1 and has a lot of Vikings. All of a sudden he can be everywhere very quickly. Reaper Harass? Vikings land in the front and back and you’ve got him. Overseer scouts? shut down. You control the map and what happens on it.
Map control is very powerful not only because you can scout but also because you can expand. If I’m starting up a new expansion away from my main, I have the choice of putting my army there, or in my main, or splitting it up. The first two options lead to suffering from harassment, the last one suffers from having poor response to a big push. However, if you have units which can quickly move around the map and shut down harassment, all of a sudden you are free to expand and out Macro your opponent. This is very much a dominate strategy in Broodwars.
Some units which help with map control are:
- Warpgate + Pylon
but this is by no means an exhaustive list.
A number of people have said that vision connotes map control, or helps a slow force respond quickly.
While vision is nice, it is ultimately a scouting technique. If you have sufficient scouting it is still possible for an opponent to launch successful harassment if you don’t have the units to respond.
Since map control is based around the Ability to Respond, having vision is largely beneficial, it reducing your response time. Additionally, being able to scout your opponents base also reduces response time. Neither of these things, in and of themselves, gives you control. The only determining factor is: can you respond?
In answer to this question I largely focused on what units gave map control instead of how to scout as scouting is largely a different question. This is not to understate its importance though.