The roach is a powerful zerg unit that can both heal quickly while burrowed and move underground but that can only target ground. While not generally well suited for late game play it is ideal for an early attack on your opponents. One common and effective strategy in 4 v 4 is to rush. The general idea behind a rush is that you sacrifice economy and/or tech in order to produce a lot of basic units early. Rushing is a lot of fun and a generally powerful and effective strategy.
The build order I have been using goes something like this.
14 pool
14 gas and second gas not long there after
queen as soon as pool finishes
roach den as soon as pool finishes
and then you start researching lair as soon as your queen finishes.
Pump some drones and try to get close to maxed one base mining if you can but it is fine to just get to say 17 drones on minerals as well as 6 drones on gas.
And that is basically all there is to it. You produce your roaches, upgrade burrow and roach speed and move out with your allies and smash the softest looking target. Hopefully your opponents will all be double expanding and teching to carrier and caught off guard by your early aggression.
You can make your units more effective through employing micro management. Against melee units such as zerglings or zealots you can hit and run while your attack cooldown is in progress. With larger HP units such as stalkers you will want to focus fire as well as hover your mouse to see if there are any weakened units that you can target and quickly kill. Once burrow is upgraded you can quickly heal your roaches, so a brief tactical retreat in order to do so is sometimes in order.
