EPT![[image loading]](http://i.imgur.com/gY94o.png)
Because when it comes to Terran vs. Zerg, I'm an asshole.
The Build
Several months ago, this strategy was really straight-forward, and I did it all the time. You send out the SCV on 10 supply and stand in the way of the hatchery. Build the barracks on 12 like normal, build the OC when it finishes, build an extra depot because with the 125 invested in the engineering bay you won't have money to do CC before depot. Zerg sees the engineering bay and knows he needs a spawning pool to kill it, so he gets a spawning pool, kills the engineering bay with lings, and expands. Meanwhile you expand when you have money (at the same time as Zerg or sooner, which is always sweet), and the game proceeds from there.
But these days everything in every matchup is about third bases. And as a result, nobody just goes pool when they see the engineering bay. In maybe 90% of games, Zerg sees the engineering bay on the natural and goes and expands to the third.
So I build bunkers.
![[image loading]](http://i.imgur.com/koLAG.png)
Because this isn't PvZ, damnit.
If you told me a year ago that I would be bunker rushing the third base of Zerg at at the 3:30 mark as part of my standard TvZ, I'd have thought you were crazy. But the bunkers generally seem to pay off relatively well, so I'm gonna keep doing this until it stops paying off. Later in the blog I'll discuss some bunker positions on third bases on a few maps because honestly, I don't think most people have much experience in placing offensive bunkers on a zerg's third base.
For now, the build.
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-Rally the 10th SCV to your opponent's natural. To be clear, that's the one that brings your supply to 10 when you start building it. The 9th SCV is the one you rally to build your first depot.
-Build your first barracks on 12 supply, like a normal opening. On ladder, I'd consider a low-ground wall-off, for reasons to be discussed later.
-You're going to need another SCV on the map to help bunker rush your opponent's third. Rally either your 12th or 13th SCV to your opponent's third. Ideally, take a roundabout route so your opponent won't see this SCV coming.
-You have enough money for the engineering bay at 13 food, but that will delay your 14th SCV. Wait until 14 food to build it. If a drone comes down to the natural to try to kill your SCV before it gets the block, dance around in the area where the hatch gets built until you have money to build it.
-When the barracks finishes, get an OC and rally your first marine across the map to your opponent's third. If there's an overlord along the way, don't stop to kill it.
-There really shouldn't be much trouble getting the bunker down. Bring one more SCV across the map around the same time as your marine finishes, to increase repair rate and as a backup if drones manage to kill one of the ones you have down at the bottom.
-Build your first barracks on 12 supply, like a normal opening. On ladder, I'd consider a low-ground wall-off, for reasons to be discussed later.
-You're going to need another SCV on the map to help bunker rush your opponent's third. Rally either your 12th or 13th SCV to your opponent's third. Ideally, take a roundabout route so your opponent won't see this SCV coming.
-You have enough money for the engineering bay at 13 food, but that will delay your 14th SCV. Wait until 14 food to build it. If a drone comes down to the natural to try to kill your SCV before it gets the block, dance around in the area where the hatch gets built until you have money to build it.
-When the barracks finishes, get an OC and rally your first marine across the map to your opponent's third. If there's an overlord along the way, don't stop to kill it.
-There really shouldn't be much trouble getting the bunker down. Bring one more SCV across the map around the same time as your marine finishes, to increase repair rate and as a backup if drones manage to kill one of the ones you have down at the bottom.
Hopefully you'll find yourself in a position like this:
![[image loading]](http://i.imgur.com/ISRKS.png)
I confess, guys. This is actually a [Girl] blog.
The Response
Engineering bay blocks are not a new idea, so I am not the first one to study this strategy. Yet at the top level you never see engineering bay blocks professional Terrans, which means they've probably evaluated the strategy and they have some reason they don't use it. Presumably there is some response from Zerg that makes this strategy come out behind, which means it would never be advantageous against a good zerg.
But I'm not a top terran, and I'm not playing against top zergs. Whatever that response is, my opponents don't seem to know it. So I set out to consistently do hatch blocks to figure out what response Zerg might have that would render this opening obsolete. Here are some of the responses I commonly see:
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-Zerg hides a drone by the natural well before he can afford the hatchery. He then waits for my SCV to check up in the main since I haven't seen a drone come down to build a hatchery, and then he builds it while my SCV is on the ramp.
-Zerg brings 2 or more drones to try to kill my SCV before it can plant an engineering bay. In a similar vein, I plant the engineering bay and he brings 3 to 4 drones to kill it as quickly as possible.
-Zerg has a drone follow the SCV that built the engineering bay across the map so it can't build a bunker, then expands to his third. The hope here is that I didn't bring another SCV so I can't threaten his third.
-Zerg expands to his third, and tries to kill the bunkers threatening it before they can finish off the hatch with drones, lings, and maybe queens. This might be the best response I've seen, but it is generally very map-dependent.
-Zerg expands to his third, cancels when he sees the bunkers, then builds lings to kill the engineering bay and takes his natural. This puts him at least mildly behind, since he loses money on the hatch cancel, and all that money was tied up in a hatch that never finished.
-Zerg expands to a hidden location. Here he is hoping that I'll assume he decided to one-base all in.
-Zerg one-base all ins. This is pretty self-explanatory.
-Zerg brings 2 or more drones to try to kill my SCV before it can plant an engineering bay. In a similar vein, I plant the engineering bay and he brings 3 to 4 drones to kill it as quickly as possible.
-Zerg has a drone follow the SCV that built the engineering bay across the map so it can't build a bunker, then expands to his third. The hope here is that I didn't bring another SCV so I can't threaten his third.
-Zerg expands to his third, and tries to kill the bunkers threatening it before they can finish off the hatch with drones, lings, and maybe queens. This might be the best response I've seen, but it is generally very map-dependent.
-Zerg expands to his third, cancels when he sees the bunkers, then builds lings to kill the engineering bay and takes his natural. This puts him at least mildly behind, since he loses money on the hatch cancel, and all that money was tied up in a hatch that never finished.
-Zerg expands to a hidden location. Here he is hoping that I'll assume he decided to one-base all in.
-Zerg one-base all ins. This is pretty self-explanatory.
So in order to assure the success of my build, I've taken these measures:
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-Always build the engineering bay. Don't run up into the main to see what he's building. The engineering bay is built at 2:15; there's nothing interesting going on in his main at 2:15, and if there is, you'll know because he didn't expand. And even if he doesn't send a drone to take the expansion, build the engineering bay anyway. It'll help you spot any 1-base aggression coming, and it'll help prevent him from taking that base if his third base attempt fails and he tries to take his natural.
-Don't fight the drone that comes down to take the hatchery. An SCV always beats a drone in a one on one fight, but he has lots of reinforcement drones nearby to help with the fight. Just dodge around in the area where the hatch is built until you have the money for the engineering bay.
-Keep the hatch-blocking SCV alive if possible. If he only sent one drone to stop the engi bay block, this should be easy. When he's attacking your SCV as it builds, stop it from building when it has 10 HP left and right click the minerals in your own natural. If he sent multiple drones from his main to stop the engineering bay, you may have more trouble keeping this SCV alive. If it dies, send one more SCV from your main in addition to that one at 12 or 13 supply.
-Rally your first marine directly to your opponent's third. When he's defending with drones he'll try to stop the marine from making it into the bunker. This can make your push fall completely flat. If you can get the marine in without being stopped, do it. Bringing your 2 or 3 SCVs to defend the marine on its path can help a great deal. If you don't think it will make it through, let it wait a little further back until you have another marine or two to drill through with.
-If he doesn't try to take an expansion, send everything home and take a safe bunker position on your natural. By "safe bunker position," I mean the bunker positions Terrans learned to use when 2-base all-ins became the Zerg standard to punish 3 CC builds. Also send one of your forward SCVs to scout for hidden expansions.
-Don't fight the drone that comes down to take the hatchery. An SCV always beats a drone in a one on one fight, but he has lots of reinforcement drones nearby to help with the fight. Just dodge around in the area where the hatch is built until you have the money for the engineering bay.
-Keep the hatch-blocking SCV alive if possible. If he only sent one drone to stop the engi bay block, this should be easy. When he's attacking your SCV as it builds, stop it from building when it has 10 HP left and right click the minerals in your own natural. If he sent multiple drones from his main to stop the engineering bay, you may have more trouble keeping this SCV alive. If it dies, send one more SCV from your main in addition to that one at 12 or 13 supply.
-Rally your first marine directly to your opponent's third. When he's defending with drones he'll try to stop the marine from making it into the bunker. This can make your push fall completely flat. If you can get the marine in without being stopped, do it. Bringing your 2 or 3 SCVs to defend the marine on its path can help a great deal. If you don't think it will make it through, let it wait a little further back until you have another marine or two to drill through with.
-If he doesn't try to take an expansion, send everything home and take a safe bunker position on your natural. By "safe bunker position," I mean the bunker positions Terrans learned to use when 2-base all-ins became the Zerg standard to punish 3 CC builds. Also send one of your forward SCVs to scout for hidden expansions.
If he's taken a hidden expansion, you probably won't find it in time to bunker rush it. That's fine, though; as long as you find it (and you should), you'll easily be able to punish it with a later push. If you choose to go for hellions in your follow-up, check back on that base to see how much static defense he's built there. If he builds a lot, just go attack his natural. If he's spined up there too, then just sit back on 3 bases and prepare for mutas.
The Bunker
I thought I'd include some screen shots of possible bunker placements for these purposes. These placements are on the third bases of these maps. I apologize that I don't have everything in the map pool included; I'll discuss why later on.
The pictures will be marked with boxes. The blue box indicates sight range of the building hatchery (3). Technically the corners of this box are not visible, but that didn't seem important to include in the diagram. The red box indicates aggressive bunker placements that might offer good surface area restriction against zerglings and drones, but will be visible from the hatchery. The green boxes indicate hidden bunker placements that will not be visible unless a drone, overlord, etc. is in place to scout for them.
Another feature to watch for is mineral patches that are in a formation that allows a space to be entirely walled off with bunkers. SCVs or marines can then be placed in this space, where they are impervious to zerglings or drones. The zerg must then either kill the bunker to get to them, or bring a queen and use its ranged attack. This will be marked with a red exclamation point.
In other words:
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![[image loading]](http://i.imgur.com/xadra.png)
Without further ado, the maps.
Daybreak:
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![[image loading]](http://i.imgur.com/RuLfU.png)
Notes: The aggressive bunkers in the mineral line are excellent for defending, but it is relatively easy for zerg to block marines from ever reaching the bunkers.
The hidden bunker at the top left is not well-protected, but it is less likely to be spotted, so you could, for instance, distract a drone with a fake bunker that is cancelled below while building this bunker above unseen.
The bunkers at the bottom right are walled against the edge, so zerg has to run around the other side of the hatchery to get to anything behind them (obviously a useful situation). They are, however, relatively exposed.
The other possible third:
![[image loading]](http://i.imgur.com/316YJ.png)
This hidden position at the top left is fairly secure because of its low surface area, and its relatively easy to get marines to it. The adjacent aggressive bunker further restricts zergling and drone access to this hidden bunker.
The lower pair of bunkers are less restrictive in surface area, and less accessible to marines. They do, however, have a longer run-around distance for drones and lings, and they have more interesting places to put repairing SCVs. Personally I prefer the higher orientation.
Note that this base does not have a lot of places to hide repairing SCVs, and there are no special formations with which the SCV can be entirely protected. On the other hand, this base is easier to bunker rush than the alternative third because the marines can more easily reach the bunker without being blocked.
Cloud Kingdom:
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![[image loading]](http://i.imgur.com/GP5LB.png)
Notes: The hidden bunkers at top are more restricted in terms of surface area. The aggressive bunkers at bottom have more surface area, but also create more enclosed areas for SCVs and are more accessible to a marine coming up from the ramp at the bottom left.
With the large number of spaces to keep SCVs, this is an excellent base to bunker rush. You might consider bringing more SCVs than you would otherwise tend to when bunker rushing this base. The biggest obstacle is getting the marine to the bunker safely.
Ohana:
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![[image loading]](http://i.imgur.com/Hdnso.png)
Notes: The bunker with the isolated SCV placement is the obvious one. This, however, is not especially easy to reach with a marine.
The hidden bunkers at the top left are relatively easy to reach with a marine; the bunker at the bottom right is the easiest to hide from a drone. Note that the bunkers at top left form a wall between the geyser and the top edge, so attacking lings must run all the way around the geyser. This means you can place repairing SCVs in the crevasse behind.
In general this is not a very easy third to bunker rush. It is relatively accessible to the zerg, and relatively inaccessible to marines.
Shakuras Plateau:
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3rd by watchtower: + Show Spoiler +![[image loading]](http://i.imgur.com/NeceV.png)
Alternate view:
![[image loading]](http://i.imgur.com/oQboq.png)
Notes: This base is relatively easy for the zerg to spot with overlords, or by holding the watchtower with a single drone. The hidden location by at the very top is fairly easy for zerg to spot from his main, but should be invisible to the watchtower (I think).
The hidden location by the watchtower is much more accessible to marines, but has a great deal of surface area. Only the closer bunker can hit the hatchery; the other bunker is out of range, and exists purely to protect an SCV, restrict surface area, and give marines a closer finish line.
3rd in opposite main's natural: + Show Spoiler +![[image loading]](http://i.imgur.com/qHrVi.png)
Alternate placement:
![[image loading]](http://i.imgur.com/rvhhm.png)
Notes:The former placement gives a large space to keep repairing SCVs securely. The latter placement has no such space, but restricts surface area a great deal more. Not shown, you could also hide a bunker at the top end of this base, but it would have relatively high surface area and be easily spotted by a drone coming up the ramp.
Alternate view:
Notes: This base is relatively easy for the zerg to spot with overlords, or by holding the watchtower with a single drone. The hidden location by at the very top is fairly easy for zerg to spot from his main, but should be invisible to the watchtower (I think).
The hidden location by the watchtower is much more accessible to marines, but has a great deal of surface area. Only the closer bunker can hit the hatchery; the other bunker is out of range, and exists purely to protect an SCV, restrict surface area, and give marines a closer finish line.
3rd in opposite main's natural: + Show Spoiler +
Alternate placement:
Notes:The former placement gives a large space to keep repairing SCVs securely. The latter placement has no such space, but restricts surface area a great deal more. Not shown, you could also hide a bunker at the top end of this base, but it would have relatively high surface area and be easily spotted by a drone coming up the ramp.
Choosing your Map
This strategy is obviously heavily map dependent. The first consideration is obvious: this should generally only be used on a 2 player map. You can send out the SCV at 10 on a 4-player map, but there's no guarantee you find Zerg in time to place the engineering bay. Of course you can take the 1/3 chance, but otherwise that's just lost mining time, especially if you send the second SCV on 12 or 13. This is why I didn't include bunker positioning screenshots for Entombed Valley, Condemned Ridge, or Tal'Darim Altar.
So why did I include Shakuras Plateau? Because it's only a 50% chance, instead of a 33% one? Well no, actually, you can get more exact than that. Here's what you do:
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-Send the SCV at 10 like normal, and rally it to the natural of the main in the opposite corner. That is, if you spawned left bottom, rally it to right top.
-When your SCV is about halfway across the map, send one of your SCVs to the edge of your main closest to the middle. You're checking for an overlord sent across by the Zerg player.
-If you see an overlord, divert your course to the close -by-air main's natural. Otherwise continue running to the other main. You should have time to run up his ramp and check for creep just to be sure he spawned there.
This way as long as he sends the first overlord directly to the close-by-air main (and he will 99% of the time), you can find him every time. If he doesn't send the first overlord across for some bizarre reason, your chances are still 50%.
-When your SCV is about halfway across the map, send one of your SCVs to the edge of your main closest to the middle. You're checking for an overlord sent across by the Zerg player.
-If you see an overlord, divert your course to the close -by-air main's natural. Otherwise continue running to the other main. You should have time to run up his ramp and check for creep just to be sure he spawned there.
This way as long as he sends the first overlord directly to the close-by-air main (and he will 99% of the time), you can find him every time. If he doesn't send the first overlord across for some bizarre reason, your chances are still 50%.
So now that you're on a 2-player map or Shakuras Plateau, choosing the map is just a matter of deciding whether or not you think you can come out ahead by building bunkers at his third base. Take a look at the bunker pictures above; if the bunker rush seems like it would be successful a good portion of the time, go for the engi bay block. If you have some better bunker positioning than I pictured above, go ahead and do it!
Remember, you don't have to kill the hatchery with the bunker pressure (although that would be nice). You just want to force out lings and queens to deal with your harass, as well as get drones off mining trying to stop you from killing the hatch. If you do it right, you should be able to force lings, queens, and even spines to stop your attack. Meanwhile you can easily have a comparably timed expansion behind. This is no 2rax pressure; you can easily cancel the engineering bay and have the minerals for your expansion almost as quickly as a standard 1rax expand.
Transitioning out of the Hatch Block
One of the nicest things about this opening is that it gives you a great deal of knowledge as to what your zerg opponent is doing. If he expands to his third and defends your bunker rush, he is almost guaranteed to be going for 3 hatches quite early. This means you're quite safe in going for 3CC yourself.
If he doesn't try to expand anywhere else, just take your natural and build a bunker with supply depots defending it. Leave the engineering bay in place; it will tell you if lings are out, and if he's really rushing a one base all-in to you, you'll see the lings running to your base with the engi bay.
As for what playstyle to transition into, that's really up to you. Because this is only 1rax aggression, you really haven't committed to anything yet. If you want to get early hellions, build a refinery before you take your natural. If you want to go mass bio, just expand normally, build a 3rd CC, and then start massing up barracks. This opening really doesn't restrict you to any particular style of play, and since it never cuts SCVs, it really doesn't put you behind in macro. In fact, since you've delayed his hatchery and forced a lot of attacking units to be built and drones to delay mining, it should put you ahead in macro if you pull it off.
One final note: if your opponent sends out an early drone scout, you block his hatchery, and then he doesn't seem to be trying to expand to his third anywhere, then for heaven sakes...
Check your main for proxy hatcheries!
If I've learned one thing about this strategy it's that it tends to frustrate opponents. And what do people do when they're frustrated if not pull out something cheesy? So just be safe; send one SCV around your main, and if you find a proxy hatchery just calmly, quietly place a bunker or two 3 range away from it and bring your marines back home.
I hope you've enjoyed this analysis of my recent favorite TvZ opening! To quote the closing to a Team Dignitas article on the QXC bunker that I liked, "may your marines safely find their way to medivacs and may your tanks rain brutal fire from the sky!"
