By Inqbus - send comments to aro(at)u.washington.edu
Problem: The terran race is often harassed in their base by the other races, protoss and zerg. Zealots and zerglings frequently are sent in to attack scvs, marines and buildings. If these enemy melee (non ranged attack) units are micromanaged well, the terran is forced to build a very compact base, which usually leaves no room for a factory, and thus no tanks/vultures. The enemy zerg or toss is then going dragoons or hydras/lurkers which own marines and medics when they show up.
Solution: To completely prevent this type of situation, one can build their first supply depot and barracks in their choke (entrance) to effectively wall the enemy units out while you start building tanks, drops, or air units. This isn't meant to last the whole game, just long enough to stop their initial rushes while you prepare to stab them where it counts.
-The block is not effective against marines, since they can target the buildings from afar without getting hit by your marines.
- For the block to finish early enough, before enemy units can get there, these two buildings must be the first ones built. The seal is not complete until the barracks is completely finished, partial buildings do not work.
-Once the barracks is done, begin creating marines to place behind the block and defend it. The marines will attack the zealots or zerglings that are milling around outside the block. These enemy units are not smart enough to target the buildings used in the block, and they will continue to run back and fourth outside like idiots while they are killed.
-It is also smart to leave an scv up near it to repair the buildings as necessary. It is a good idea to also build a bunker behind the supply depot to further fortify the area.
-Once the enemy sees that they cannot easily get in with melee units. They will switch to ranged units, air, drops, or cloaked units. Clearly the block will not keep them out for that long. Soon after the block is complete, build a turret or two to detect cloaked units.
-Tanks will need to be placed behind the block quickly, as they have much greater range than marines and will help defend the block greatly.
-If necessary, fly an extra building out to scout the area outside your block, this helps to allow the tanks shoot farther.
Diagram: This image shows the best way to block your entrance for every starting spot in BGH. Print it out and use it for reference when playing terran on bgh.
(Click To Enlarge)
Other Uses: It can also be fun to block other people into their bases by building these buildings in their choke. Then place your tanks behind and start pounding them. Or possibly on a 2v2 you could go into the enemy base and block their entrance behind you, preventing their ally from helping them.