Bionic Terran vs. Zerg Timing

[e][h]Terran vs. Zerg - Timings

Terran sieging Zerg's Third Gas Expansion

Strategy Information

Matchups:

TvZ

Type:

Opening

Bio Terran vs. Zerg is a fast-paced match-up with the intensity of the Terran Ball facing off against the mobility and numbers of the Zerg army. Throughout the match, both Terran and Zerg have various opportunities to exploit the other's weaknesses and are able to apply pressure, which is an invaluable asset to success in StarCraft. This article explores the Timing of these strengths and weaknesses, as well as strategies for players to perform and exploit.

Gameflow Overview

The Bio TvZ match-up can be divided into three phases: Early-, Mid-, and Late-game. These three phases tend to correspond to the three tech tree levels. The three tiers for Terran are Barracks units, Factory units, and Starport units. The tech tree levels correspond to the Hatchery evolutions for Zerg: Hatchery, Lair, and Hive. Here is a brief overview of the common interactions within each phase:

• Early-game has Zerglings (with possible speed upgrade) against Marines, then Medics and Firebats.
• Mid-game adds either Lurkers or Mutalisks (Lair Tech) versus Marines and Medics with static defenses; Terran can eventually move out after his first Science Vessel pops out, usually accompanied by 3 Siege Tanks to take out containing Lurkers or apply pressure to a Zerg base.
• Late-game involves Defiler play vs. mass Tanks / mass Science Vessels; Dark Swarm, Plague, and Ultralisks/Zerglings against Marines, Medics, Firebats, Science Vessels, and Tanks.

General TvZ Timing Attacks: Before Lair and Before Defiler

• The Sparks Terran / 3 Barracks Sunken-break builds are examples of "Before Lair" timings, when the Zerg only has Sunken Colonies and Zerglings (often with Metabolic Boost, the speed upgrade) to deal with your MMF (Marine, Medic, Firebat) force. Pre-Lair timing attacks have the potential to end the game quickly, but can be easily defended by decent opponents with good game sense. if the Z knows that you are going for the kill, they will put down several Sunken Colonies and make more Zerglings to deal with your attack. This will hurt the Zerg economically, but the damage to Terran's build and economy is even greater. Pre-Lair timing attacks work well if the Zerg is denied information about the Terran's army size, composition, and delayed expansion timing. However, this is very difficult to do against experienced opponents.

• The most common TvZ timing push comes as soon as your first Science Vessel finishes (with Irradiate almost done), aiming to hit before Consume is finished. You should have at least +1/+1 on your infantry upgrades, and should have 3 Siege Tanks from your Factory. Later on you can discontinue Tank production and add another Starport for more Science Vessels instead in order to progress into SK Terran. Your Vessel allows you to save Comsat Scans, and your Tanks have farther range than lurkers do - even unsieged. This Pre-Defiler timing is sometimes not actually before Defiler, and sometimes several minutes before hive, depending on how fast the Z wants to get to Hive tech. The general prerequisites are:
  • Zerg has recently taken a third gas expansion, and is thus slightly weaker macro-wise.
  • Terran army can overpower the Zerg units.
  • Mutalisks have either been wiped out or are no longer that effective.

• You shouldn't expect this push to win you the game against a good Zerg, but you may be able to take out his third gas or at least wipe most of the Zerg army. Even just gaining map control is crucial, as Defiler+Consume+Swarm at Terran's front door will pose an extremely problematic situation for the Terran player. Make sure you don't lose your Vessel to Scourge.

Early Game

The early game generally consists of early Zergling pressure followed by Marine and Medic pressure into the mid-game.

Scouting

Scouting earlier will make you safer, but hinder your economy. Terrans tend to scout somewhere between 9 and 12 supply with scouting on 11 being by far the most popular. If you scout very late you risk facing an unscouted cheese. A late scout against 9 Pool Speed will make it extremely difficult to get good information about the Zerg base.

On 2-player maps such as Blue Storm where the rush distance between naturals is somewhat larger than the distance between two adjacent naturals on a 4-player map like Python, it is very common to 11scout (using an scv after your supply depot finishes) in order to deny the Zerg's second hatchery in a 12hatch build. On 4-player maps like Python, you can get lucky with your scout (11 or 12 supply) and deny the natural expo for a bit as well.

If you scout the Zerg last, it is very possible that you will scout his base after he arrives at your base if he went 9 pool speed. To combat this, if you 11 raxed, send two SCVs. to your ramp as your first Marine finishes and put them on hold position to defend. You should not bring back the SCVs until you have enough units to retake your natural. If you 14CCed, it is practically impossible to recover against an equally skilled player in most cases.

To minimize the risk of losing on account of poor scouting, a Terran player should do two things during the early game:

1. Watch the edge of the fog around your base for any Overlords. Often, a good Zerg will see your SCVs or Command Center and turn around in order to avoid detection. Watching this area will sometimes let you catch the scouting Overlord before it retreats. By seeing it, you know which base the Zerg is at, and consequently, which direction to scout.
2. Scout the closest direction first. Since Zerg can't proxy in the middle of the map, scouting the middle of the map early on makes no sense, and cross scouting makes no sense unless you have a really aggressive build that you don't want to use against a Zerg at cross positions.

Things to remember about scouting timing:

• How likely will your opponent cheese? The more likely it is that your opponent is going to cheese, the earlier you need to detect it.
• How large is the map? A larger map takes longer to scout, but also takes longer for enemy units to traverse. Proxying mitigates the travel distance.
• How many starting positions are there? Maps for more than two players have additional starting locations to scout. Cheese is less likely to work unless the defender is located early.

Adaptations

Once you get your scouting information it is imperative that you be able to adapt to your opponent. Continuing down a path with blinders on will only end poorly.

9 Pool Speed

If Zerg has a Spawning Pool up and is mining off an extractor, there is a possibility that the Zerg will attempt to attack with Speedlings. While Zerg has Speedlings roaming the map, you may not be able to expand as easily, since Marines must be used to prevent a run-by. There are a few things that you can do to deal with fast Zerglings:

• Fast Wall; While it is easy for Zerglings to fit between buildings, you can pull SCVs to block your wall.
• A second Barracks: If you were planning to 1 Barracks FE and you scout a 9 Pool Speed, it is possible to throw down a second Barracks before your Command Center to cope with the extra Zerglings
• Build your Command Center in your main and hold your choke while you tech normally; if Zerg stops ling production simply take your natural, if Zerg continues to mass lings he may be at a bad economic position as well.
• Once you reach Academy Tech, you are free to clear your natural and expand.

12 Hatchery

If the Zerg has placed a fast Hatchery he generally won't be able to apply pressure to an expanding Terran. He can however disrupt an expansion by moving Zerglings into the natural. Scouting no gas or research going on the Spawning Pool means that:

• A Terran can One Barracks FE to match Zerg in Economy
• A Terran can 2 Rax Fast Expand to pressure Zerg until mid game
• A Sparks Terran build can move to break the natural and even end the game

Applying Pressure

When you reach Academy Tech, you can apply pressure in return, allowing you to assert map control up until Zerg reaches Lair tech, which forces you back to defend a Mutalisk harass or a Lurker Contain. Be careful of a Zerg backstab when you move out with your initial MnM brigade. A wily Zerg can hide 12 speedlings, allow you to get half way to his base and then either counter your undefended expansion or flank you from behind as you attack the sunken line. If there are two routes to the enemy base (e.g. Heartbreak Ridge, Luna or Sin Cheupung) send an SCV to scout the other path as you move out.

Mid Game

Mid game in Terran vs. Zerg is defined as Lair tech pressure from Zerg (either Mutalisks or Lurkers) followed by a Terran Timing Push.

Scouting

At this point you need to make good use of the Comsat station(s) in order to keep tabs on Zerg and to gauge when Zerg will move out with Lair Tech. With one Comsat at the main and one at the natural, you can keep an eye on Zerg's two bases.

Adaptations

Terran in mid game is either going to have to deal with Mutalisks, who's mobility corrals Terran in their base or Lurkers, who's burrowed status prevents Terran from being able to engage the Zerg Army.

Spire

If you scout a Spire, you will need to retreat your Marines and Medics in order to protect your base. Zerg will maintain map dominance until you reach Starport tech so you should tech up quickly in order to stop the Mutalisk Harass.

Hydralisk Den

If you scout a Hydralisk Den, you can stay out with your initial force, Lurkers will push you back towards your natural. While you can use scans to combat small numbers of Lurkers, it is advisable to tech to Science Vessels in order to break the Lurker Contain.

Applying Pressure

Once you reach Science Vessels, you can push out and even attempt to Timing Push the Zerg. This timing window is open from Zerg taking their Third Gas Expansion until they reach Hive Tech. This is one of the points at which you can punish the Zerg with timing attacks. You could e.g. attempt to break the natural expansion's Sunken wall to end the game before it reaches Hive Tech. At this point in the game Zerg has taken their Third Gas Expansion but has not yet reaped the rewards of running three Extractors and thus cannot afford Hive Tech units. The Timing Push aims to exploit this temporary weakness.

The timing window for this build begins when the third Hatchery finishes and ends when Zerg reaches Hive Tech. Terran at this point has reached Science Vessel Tech, has 1/0 or 1/1 infantry upgrades and is able to assert themselves against Mutalisk harass or Lurkers out on the field. Terran must also be able pump units from six production facilities uninterrupted.

The Terran army should be able to push out to the Natural expansion and set up at the natural choke. Initially it is good to set up within siege range but not move in with Marines and Medics until Zerg attempts a counter. This way Terran can protect against a flank while still breaking down the Sunken Colony wall. Once the Sunken Colonies are down Terran can push in with Marines and Medics and attempt to drop the Hatchery. A few things to remember:

• As it is a push, it is important to move your forces slowly as to not get flanked by Zerg's quicker speed.
• Do not try and force your way through until after the sunkens are down unless you have to.
• Letting your Science Vessels get killed by pairs of Scourge is a surefire way to get your push wiped out by Lurkers.

Late Game

While standard late game in Terran vs. Zerg does not offer an opportunity for any sort of timing based pressure it is still important to keep tabs on Zerg in case they attempt to do a Tech switch.

Scouting

While most Zerg play Ultralisk/Zergling as their late game build it is possible for them to switch to Guardians. Therefore you should continue to scan for a Greater Spire being evolved to catch the Zerg going Guardians. This does not necessarily mean mass Guardians; it could be that Zerg plans to upgrade the Mutalisks left over from mid game.

Adaptation

In the event that Zerg techs to Guardians you have to scout it early. You can use SK Terran to counter this, as the Vessel Cloud is adept at killing Guardians. Secretly constructing Starports and taking out the Guardians with Wraiths is also an option.