This is a strategy to prevent your enemy from being able to move freely around the map. The advantage that the zerg have is that they can expand very quickly thanks to their cheap hatcheries and fast moving units.
The first structure you want to build is a supply depot. Then build barracks. Then build a refinery. Add a Tech Lab to the Barracks so you can start creating Reapers. When you’ve reached 50 gas credits, research Nitro Packs for the Reapers. You can use Reapers to move around the map and establish some control. This is a great way to see if your Zerg opponent has started expanding on him. Build your second Refinery and 2 more Barracks with Tech Labs. The reason for building more Barracks is that Reapers take a long time to build.
As more Harvesters are created, start attacking your enemy’s base. When attacking, be sure to micromanage them. Reapers work really well because they have a longer range than Roaches and Queens, and micromanaging is the key to taking advantage of this advantage. The last thing you want to do is waste your units by sending them on a suicide mission. One positive side of using Reapers is that they are cheap to create. If you play it right, you’ll have enough minerals to build a second Command Center after a couple of Barracks.
One thing to keep in mind is that 4-5 mutalisks attack your base. A good strategy against them is to build 2-3 Turrets around the Command Center.
