EPT
First, some background: back when I was in Gold League, the THING I did against protoss was rush cloaked banshee. This might seem dumb and ineffective to most of you who rely on 2 gate robo or 3 gate sentry expand with a forge against terran, but down in the nether leagues where 80% of protoss blind 4gate, a cloak unit against the no-detection build was horrifically effective.
With time, I progressed into Plat League, where protoss players would sometimes not 4gate. I learned how to scout for non-4gate builds (used up chrono, more / earlier gas, etc), and react accordingly. I adapted by 1-1-1 to be a more aggressive play against protoss who fast expanded by developing (what I'm sure many others did as well) a marine tank banshee push, with no siege, no stim, and no cloak.
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![[image loading]](http://i.imgur.com/unEvvl.jpg)
This is going to go well, I can feel it.Although a tech-ey 7:30 minute push might be good against a protoss player who expos right then, it would crumple against an appropriate mix of sentries and stalkers, forcefielding tanks away, guardianshielding down the marine and banshee dps, and generally being Protoss-ey. Eventually, I realized that running up a narrow ramp against a flurry of forcefields wasn't going to do.
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Protoss: come on up this ramp, I dare you. I double dog dare you, cmon... try to outrun my forcefields. Some thinking eventually lead to the development of a Marine Tank Banshee contain that saw some modest success. I'd bring along a couple scvs with my attack, and if he had too many sentries, I'd make bunkers in his nat, research siege, and contain him onto 1 base while expoing myself.
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![[image loading]](http://i.imgur.com/IYuiIl.jpg)
This rarely went well. Between warp prism drops, DTs, void rays, secret expos, blinking out of his base, lowground warp-in flanks, and all manner of other protoss trickiness, I'd usually end up losing scvs or my base or just having the contain broken.
Everything changed with the advent of the Engineering Bay. Incorporating an offensive sensor tower let me see if he was trying to drop or blink out of his base, and missile turret kept DTs, observers, and immortal /zealot drops away from my tank line. On most maps, 2 offensive sensor towers led to complete containment, letting me expand in absolute safety. If he tried to drop, do low ground warp-ins, or sneak void rays out, I'd know and react accordingly, able to guage exactly how much of my army needed to be at the front, and how much needed to be elsewhere. I'd see his troop movements and building locations, letting my scans and scouting be more effective as a result. the information asymmetry grants a huge advantage to the terran player.
Recently, on the ladder, most of my mech play against protoss has been a marine tank banshee push, and if that fails, a transition into a tank heavy contain with statics and sensor towers. Terran 1 base is stronger than Protoss 1 base, and if I can take my 2nd without him taking his, it's game over.
Here's a Battle Report of my most recent game using this strategy.
and a replay for those of you who have time: http://www.sc2replayed.com/replays/162802-1v1-terran-protoss-backwater-gulch
Next week, I'll go in depth on the usage of sensor towers offensive and defensively in the TvP matchup, and the power of this often-overlooked building.
