"Capture the hill!" is staple fare for war movies. And the battle extends through, often predictable, twists and turns for the rest of the movie till our heroic soldiers finally get to capture that hill.

Why this fascination with hills? Hills, in military parlance, are "Dominating Ground". They overlook the entire area around them, affording the side holding the hill the advantage of an unobstructed view of a far larger area as compared to being at the bottom of that hill. And, thus, the ability to shoot at anything that moves across this area.

Say, you are the first one to get to occupy the only hill in the desert. You can then pound the enemy at will. And if pounded long enough, with sufficient intensity and regularity, you just might get him to leave.

The guy at the receiving end knows this too. So he launches an attack to capture the hill. Already being on that hill, you have a far easier time, you just need to keep firing bullets at him.

And then you run out of bullets.

First mover's advantage (FMA), in the business battlefield, is the hill. And bullets, the resources required for sustaining this advantage.