You will as player meet the Encounter battle-type already from tier 4.
The Enocunter battle type is different from the Standard battle-type, by the fact that there's a white flag somewhere on the map.
It's THAT flag, your team is about to fight on making either green or red.

An example of an Encounter battle.

What players need to practice on, is make their gameplay more dynamic, to the type of the battle.

By seeing it's an Encounter, we already know a few things.
1) The time is shorter, 10 minutes.
2) The base is the important part.

The forest only becomes relevant, for the matter that the enemy team are going to flank your team out.
Again, my own experience says: "Open flanks invites the enemy"

-So. If a team leaves a flank open, then it's most likely, from THAT flank, where most of the enemy team are going to be. -It have happened to me.

We can add a thrid thing, to the list of what we know. 
And that thing is, that in this case, your spawn point is not your base. So that's why it's NOT important.