The Baneling / Roach Build is a great way to counter turtling Terran players teching to Siege Tanks or Banshees. The build is ideally used against Terran although can also be used against Protoss players who are trying to tech quickly to Void Rays as well.
The focus behind this build is to take out the Terran made wall of Supply Depots and/or Barrack’s. The plus of taking out the Barrack is more room and faster movement into the Terran base. The negative is more the Barrack’s(1000) has more Hit Points then the Supply Depot(350). The technique is to destroy the Supply Depot’s with your Banelings and then push through with your Roaches while he is teching. This leaves the Terran player with less units than normal since he/she will be hoarding gas and minerals for the Banshees and Siege Tanks.
The key factor to this and other strategies is to scout your opponent early and often. Early on if the player is getting 2 gases, that is a sign of teching which means the player is usually going 1 or 2 Barracks than straight into a Factory. The Banelings and Roach build can be successful even if he builds a a couple Barracks by using the Banelings to take out grouped up units.
10/10 -> Build Drones
12/10 -> Double Extractor Trick to build 2 additional Drones
12/10 -> Build an Overlord
14/18 -> Build an Extractor
15/18 -> Build a Spawning Pool
15/26 -> Build a Roach Warren
15/26 -> Build a Queen
17/26 -> Build a Zergling
17/26 -> Build a Zergling
19/26 -> Build a Baneling Nest
19/26 -> Build an Overlord
19 – 28 -> Build Roaches
Once you are ready attack with 4 Banelings and 5 Roaches. The time you should be aiming for is a around 6m 15s Replay Time, and 4m 20s Real Time.
When you are ready to attack set your Banelings to a control group and your Roaches to another Control Group so you can quickly access them. Run your Banelings first into a Supply Depot to take it out and than bring in your roaches.
When you are attacking if your opponent has a lot of Marauders quickly produce Zerglings with Zergling speed upgrade to take out the marauders. The same goes when playing against a Protoss if he has a heavy Stalker build than Speedlings mixed in with your Roaches will be a great combination.
You can recover in economy if you don’t win immediately by building a hatchery your at your natural expansion right before the attack.
This only works against a Supply Depot or add-on style wall-in.
If your opponent has a lot of Marauders / Stalkers use Speedlings to counter them.
You can build a couple extra Banelings to take out any bunched up Marines / Marauders they have once you break through.