Many of you may have seen in Day 9 Daily #260 - Funday Monday: Contaminate This! the usefulness of Overseers and Contaminate.
What I saw in the ZvZ match up of this Daily was extremely interesting and massively game changing, and I think that it could really change the ZvZ metagame once people realize how powerful this tactic is and how to use it properly.
Just a disclaimer, I don't play Zerg at an extraordinarily high level as my main race is Terran. However, I do want to get some discussion going, as well as lay a basic build out that has worked quite well for me when I've played this matchup. I hope for an insightful discussion with possibly some thoughts from the higher ranked players.
The build order itself is very simple. 7 Roach Rush to try and do damage/defend. Get Lair ASAP afterward and get 3 Overseers for constant Contamination, followed by Roach Speed and mass Roach followup.
15 Pool 14 Gas 15 Overlord Queen + 4 Lings Roach Warren 7 Roaches Immediately take 2nd Gas Lair at next 100 Gas ASAP 3 Overseers at 300 Gas Roach Speed -> Mass Roach Expand when you feel possible Evolution Chamber x2 -> Range + Carapace Upgrades
With this certain build, you can keep heavy Roach pressure on your opponent at all times, while not allowing any reinforcements to be made after your initial engagement! You also get a decent economy flowing with the 15 Pool.
The early 7 Roach Rush allows you to deny an early expansion from the opposing Zerg and allows you to wall off your ramp if you need to defend against a speedling/baneling opener. In the current state of ZvZ, it is not uncommon to see the entirety of a game played out with Roach wars, where the winner has better upgrades and unit support, such as Infestors. Getting an early head start on Roach production will put you in a solid mid game situation and gives you something you can expand behind safely.
The power behind this build is how the Contaminate mechanic works. When you Contaminate a Zerg Hatchery, progress of Spawn Larva and passive Larva creation is halted. This means as long as you keep the Hatchery contaminated, your opponent has no larva to make units. Also, if the queen tries to reinject larva, the timer is reset! At one point in the Funday Monday, one Zerg was able to get a 37 Supply lead through constant Contamination and roach production back at home. Holy crap!
Let's take a look at the Overseer and the Contaminate spell.
Overseer
200 Health 0 Armor 1.875 Movement Speed Cost 50 Minerals and 100 Gas to make Evolves from Overlord after Lair has been researched Morphs in with 50 Energy
Contaminate
Costs 75 Energy per cast Has a 30 second duration on affected target Duration is refreshed when recasted on affected target
We also need to look at the Queen vs Overseer.
Queen
.9375 Movement Speed Air Attack: 7 Range 9 Damage 1 Second Attack Speed
This means it takes a Queen at least 23 shots to kill an overseer. --------------------------------------------------------------------------------------------------------------------------------
The energy regeneration of the Overseer is 0.5625 Energy/Second, similar to the rest of the units in Starcraft 2 (excluding PDD). This means that you can cast one Contaminate every 133.333 (repeating of course) seconds.
With three overseers all starting at exactly 75 energy constantly using Contaminate on a hatchery, you can cast 90 seconds worth of Contaminate with only a 43 second down time before you can restart your Contamination cycle. You can pump out 14 Roaches in that 90 second time period! This gives you a free 28 supply lead assuming you can afford it.
Now, where this really shines is if you are attacking your opponent during this 90 second window, while constantly sending in reinforcements. Your opponent cannot refill his army because you have effectively cut off any way of him remaking units! At the very least, you will be able to trade armies in your favor and possibly snipe an expansion/kill lots of drones or flat out win the game.
There are 4 openers I have in mind that I will discuss.
1. Fast Expand 2. Speedling/Baneling 3. Roach Rush 4. 1 Base Muta
Fast Expand
We're starting to see fast expansions more and more in ZvZ as the matchup progresses. The goal is to get a strong economy early, while defending against pressure with spines and lings so that your midgame is stronger than the opponents. With a 7 Roach Rush, you are able to hit the other Zerg before Zergling Speed kicks in, and with proper micro, you should be able to force a cancel or snipe the expansion.
Should the expansion go up and is properly defended from the first wave of attacks, you need to continue Roach pressure to deny droning and punish the other Zerg as much as possible. Your goal if possible is to snipe Queens as well. With two hatcheries to Contaminate, you want to be focusing on the hatchery without a Queen to stave as much larva production off as possible. Don't overcommit too heavily. As long as you are contaminating constantly, you will slowly start to pull ahead in supply.
Speedling/Baneling Opening
If you scout this opening, it is really integral for you to get a spine crawler+queen to kite your drones around until you are able to get your first few roaches off. Once they are out, you can block your ramp with and redrone if necessary. As long as you don't lose too much, you can still catch up if you fell behind once the contamination cycles begin.
Roach Rush
This is a matchup where you'll really notice how much Contaminate helps. Assuming you're both starting on equal roach numbers, you will be able to slowly outproduce your opponent as the game goes on due to your Contaminations. Be sure to not overcommit with any attacks and get a spine or two if you think he will be able to overwhelm you while you are teching.
If your opponent decides to expand behind his roaches, you will be easily able to overwhelm him once you get the Overseers and start pumping roaches again. He will simply not be able to resupply due to low larva count and the money spent on the expansion.
1 Base Muta
This build can either be really easy, or really difficult to deal with. Ways to tell this build is coming is if your opponent completely walls off with spines. This is because he wants to tech as fast as possible with minimal defense. The spines will be too much of an overcommitment to break early, so focus on teching as well and getting extra Queens + spores to defend. Once you start contaminating and massing roaches and/or hydras, you can simply overwhelm his small muta ball and low ground army count.
Be careful of getting your overseers sniped and losing too many drones to harass. It's safer to overcommit on defense so that you can tech AA safely. 1 spore + 3 queens should be enough for one base.
If you aren't able to kill your opponent by limiting his army, you can make a few tech choices. You should already have started upgrades for your roaches. If it turns out to be a typical Roach war, better upgrades and some infestors for Fungals will help a lot. DON'T STOP CONTAMINATING! This is where your real lead comes in. If you are able to slow his production at all, while maintaining yours, you will be able to come out ahead through numbers alone.
If he is able to tech Muta, you can either go Hydra-Infestor or go Spire tech to deal with that as well. If you have an extremely sizable Roach army however, you can just run into his base and kill everything you can, simply because Mutas will not be able to DPS down all your roaches before a critical amount of damage has been done.
Early pressure before your roaches spawn will hinder you, just like it would in any ZvZ matchup. You need to be diligent about scouting do that you know what to expect so that you are not caught off guard. Speedling runbys can be extremely annoying if your roaches are caught out in the middle of the map. This can be remedied with a couple spines and the next wave of roaches you spawn.
The matchup itself plays out the same way it always would before, except you will be using Overseers to help slowly pull ahead in supply.
If both players were both to use Contaminate on each other, whoever has the better macro at that point should win, because they will be back on equal footing. A spore crawler in the vicinity of your hatchery should help deter Overseers a bit, but they are very beefy units that can move in and contaminate quickly without taking too much damage.
More replays will be added when I get home. I will also add other user replays here, as I really won't be able to play too many high quality games with this myself.
Again, I am not a heavy Zerg user and instead I want to spark some discussion between you Zerg players. This opener isn't the exact way you have to play with Contaminate. This is simply what I've found to work for me. I'm hoping to hear about other strategies that may have a Speedling/Baneling opener instead, or something along those lines!
Looks good mate. Still not watched that funday, will have to catch it at some point.
Always thought that zerg should use contaminate more. Seems like such a good "spell". You could time contaminate as you attack their base and prevent reinforcements; target an expansion and prevent him building any workers.......options are endless
ONe question, if something is already being built, say a collosus, does contaminate cancel it? or does it just pause it?
TIP: Comes before what is ready? Contaminate? many things do mate. This is a mid game strat, not early game
The 7-roach-rush is a very weak all-in that relies on your opponent being bad. Furthermore, 3 overseers is 300 gas. That's 12 more roaches you could have, all things equal. You can just go kill him.
On February 26 2011 01:05 T.I.P. wrote: 1 base roach rush with +1 attack comes before its ready and beats it srry
1 base mutas is also ineffective because it takes too much time to get lair tech and spire is just way too long
I'd like a little more detail than this....timings? I don't think I ever implied I would go 1 Base muta either o.O
Either way, why would a +1 push best mine? 7RR hits before upgrades are done, and then I can pull back and remass while contaminating and use spines defensively.
On February 26 2011 01:17 mofisto wrote: Looks good mate. Still not watched that funday, will have to catch it at some point.
Always thought that zerg should use contaminate more. Seems like such a good "spell". You could time contaminate as you attack their base and prevent reinforcements; target an expansion and prevent him building any workers.......options are endless
ONe question, if something is already being built, say a collosus, does contaminate cancel it? or does it just pause it?
TIP: Comes before what is ready? Contaminate? many things do mate. This is a mid game strat, not early game
It would only pause the production of the unit being made for 30 seconds, and then continue where it left off after the effect wears off. Contaminate will find its niche eventually. I just want to help it progress there ^.^
On February 26 2011 01:22 OmNomSpy wrote: The 7-roach-rush is a very weak all-in that relies on your opponent being bad. Furthermore, 3 overseers is 300 gas. That's 12 more roaches you could have, all things equal. You can just go kill him.
I disagree very very much that it's all in. You don't have to fully commit to an attack, and you can expand with the roaches as defense instead. It's only seems like an all-in in a non mirror matchup, simply because Zerg should FE in those and not 1 base. Not the same case in ZvZ
And 3 Overseers may be worth 12 roaches, but the production halt is worth much more than that. Like I said, I'm not really a Zerg aficionado, so there may be better ways of going on about this. What suggestions do you have?
I've been seeing overseers being used versus me a lot. They're definitely good, but I'm not sure if I would want to base my entire strategy around contaminate. I can get by using my regular mass roach mass upgrade style, so I always prefered getting more roaches over using the gas on overseers. And ZvZ is definitely my best MU.
Having that said though, I do feel that contaminate could fill in the harassment role in 2 base v 2 base situations. Seeing as usually both zergs turtle at their natural, harrassing with zergling run by's or baneling run by's is very bad. They hardly ever are cost effective.
However, I dislike the feeling of not being in control of my opponent by not harrassing or having map control. So I might have to find a way to squeeze in a couple of overseers for harrass purposes ( and not having to rely on pure macro to save me ). Besides, think if all the minerals you will save! You can probably expand sooner if you make some overseers instead of roaches.
Every time I try this, my opponent scouts the overseers (or sees them in his base), throws down a spire and barely eeks out like 2 mutalisks and then my roach army has to turn back (because I haven't gotten that huge supply lead yet) and my overseers need to scatter and then I have to wait until infestors/hydras. Am I just too slow?
Against a 2 bases wouldn't contaminating tech structures be more worthwhile? If you contaminate the Roach Warren then they can still produce from both hatch but they are stuck making lings or drones no? Might delay upgrades too.
On February 26 2011 01:25 Chaosvuistje wrote: I've been seeing overseers being used versus me a lot. They're definitely good, but I'm not sure if I would want to base my entire strategy around contaminate. I can get by using my regular mass roach mass upgrade style, so I always prefered getting more roaches over using the gas on overseers. And ZvZ is definitely my best MU.
Having that said though, I do feel that contaminate could fill in the harassment role in 2 base v 2 base situations. Seeing as usually both zergs turtle at their natural, harrassing with zergling run by's or baneling run by's is very bad. They hardly ever are cost effective.
However, I dislike the feeling of not being in control of my opponent by not harrassing or having map control. So I might have to find a way to squeeze in a couple of overseers for harrass purposes ( and not having to rely on pure macro to save me ). Besides, think if all the minerals you will save! You can probably expand sooner if you make some overseers instead of roaches.
So do you think it would be a better idea to implement more overseers later once you've established defenses and an expo? The great thing about overseers is that they keep their effectiveness through the entire game. Contaminate will always be useful in every situation, whether you're halting upgrades or stopping larva production so that you can pull ahead.
On February 26 2011 01:26 aeoliant wrote: Every time I try this, my opponent scouts the overseers (or sees them in his base), throws down a spire and barely eeks out like 2 mutalisks and then my roach army has to turn back (because I haven't gotten that huge supply lead yet) and my overseers need to scatter and then I have to wait until infestors/hydras. Am I just too slow?
Spires take a long time to build, so I would assume since he invested in that, he would be a little lighter on defenses. I can't say for sure, but my gut says you're going a little slowly if he has time to get a spire up and not die to roach pushes.
On February 26 2011 01:33 KissKiss wrote: Against a 2 bases wouldn't contaminating tech structures be more worthwhile? If you contaminate the Roach Warren then they can still produce from both hatch but they are stuck making lings or drones no? Might delay upgrades too.
I don't believe contaminate works like that. It would only pause the upgrades on the Roach Warren, not completely disallowing roaches to be produced.
7 RR against Zerg kinda sucks. Any FE or speedling build will be able to have enough lings to cost-effectively beat it off while having more drones than you. Roaches in low numbers are only dangerous vs equal-resource lings if 1) you have +1 or 2) you get good positioning (ex: you manage to get behind his minerals) or 3) you catch him by surprise and he's supply blocked or is missing injects You dont have time for 1), can't reliably do 2) and 3) shouldn't happen to a good opponent.
If you really want a contaminate build, just do Day 9's ZvZ quick lair opening. It seems like a much more resonable way of rushing overseers.
On February 26 2011 01:25 Chaosvuistje wrote: I've been seeing overseers being used versus me a lot. They're definitely good, but I'm not sure if I would want to base my entire strategy around contaminate. I can get by using my regular mass roach mass upgrade style, so I always prefered getting more roaches over using the gas on overseers. And ZvZ is definitely my best MU.
Having that said though, I do feel that contaminate could fill in the harassment role in 2 base v 2 base situations. Seeing as usually both zergs turtle at their natural, harrassing with zergling run by's or baneling run by's is very bad. They hardly ever are cost effective.
However, I dislike the feeling of not being in control of my opponent by not harrassing or having map control. So I might have to find a way to squeeze in a couple of overseers for harrass purposes ( and not having to rely on pure macro to save me ). Besides, think if all the minerals you will save! You can probably expand sooner if you make some overseers instead of roaches.
So do you think it would be a better idea to implement more overseers later once you've established defenses and an expo? The great thing about overseers is that they keep their effectiveness through the entire game. Contaminate will always be useful in every situation, whether you're halting upgrades or stopping larva production so that you can pull ahead.
I think it would be best to set up a defense BEFORE you go for overseers. As in, not 1 basing and hoping the opponent doesnt already have a full economy up and running.
In my own personal experience, playing reactive ZvZ is greatly more effective than forcing yourself into one build. For example, I like to get speedlings up and get a banelings nest building, but if I scout a hatchery going down or I see roaches, I will cancel it. With a contaminate rush this is not the case. You're basically giving your opponent freedom to do as he pleases, which in the worst case would be an expansion, until your lair finishes and your 3 overseers are up.
So basically what I am saying is, until you have your second base online with somewhat OK saturation, its pretty gimmicky to go mass overseer. Because you're investing your gas into overseers ( also known as non-roaches and non-upgrades ) your army will lag behind initially. You will only get ahead in army count once you have contaminated him a couple of times. So its best to get a reasonable force up before you invest so heavily into something that can't kill his existing roach numbers.
But in this 2base vs 2base situation, since neither zerg is able to have map control without cutting into drone numbers ( which is already playing into your opponents hands ) I can see overseers really make a difference. As your opponents production is effectively lessened, he is forced to rely on a smaller roach army and drone up, or forced to only make roaches to defend a push. Either option is risky, the former is weak to a frontal push, while the latter is weak to being outmacroed.
I definitely have to explore this more. And I definitely will since I get into these 2bv2b situations a lot.
On February 26 2011 02:07 SpaceYeti wrote: Would be nice if when people post their well polished guides that they would upload them to Liquipedia II.
Yes, but the ideas should be polished, not just the presentation. I'm very skeptical of mass contaminate in zvz. You can only push an overseer in 2, maybe 3 times against someone with good overlord spread who can spot you coming in, as soon as the second contaminate goes down you can afford a macro hatch and make up for the production.
One note though, and this is kind of a bug. Even if you've already spawned larva your hatch you can spawn larva again while it's contaminated, but there's no reason to do this, it just wastes queen energy. I kind of think think it's a bug as it shouldn't allow you to do this.
On February 26 2011 01:24 Synystyr wrote: I disagree very very much that it's all in. You don't have to fully commit to an attack, and you can expand with the roaches as defense instead. It's only seems like an all-in in a non mirror matchup, simply because Zerg should FE in those and not 1 base. Not the same case in ZvZ
Yes, you can expand off roaches, but you are going to be a few drones behind. We're talking at least 3 drones here the moment you throw down the expansion, probably more given the fact that you stop droning at 14 before roaching. In reality, you're not just 3 drones behind, but 10+ drones behind 10 minutes later in the game. That's why committing to a 7 roach rush -even just building the roaches as part of a roach expand- is all-in against hatchfirst/speedling fe; you honestly have to kill your opponent or just be way better than they are to have any chance in the mid-game.If you don't want to call it all-in, then just call it bad, because that's what it is. This really isn't up for argument; you either win in the early stage (against a bad opponent), or you lose in the mid-game to an equal or stronger opponent.
On February 26 2011 01:58 Sbrubbles wrote: 7 RR against Zerg kinda sucks. Any FE or speedling build will be able to have enough lings to cost-effectively beat it off while having more drones than you.
This elaborates my point a little more. Even in the closest of positions you can defend 7 roaches quite handily with reactionary ling or ling/roach. I could honestly write a whole-page post on why 7 roach rushing in ZvZ is terribad, but I'll get more on the point of overseers.
Building 3 overseers is risky since you can basically be killed by any timing attack. I'll give an example: you are on par with your opponent, both getting lair at around the same time. Around the time your 3 overseers get into his base with enough energy to contaminate his hatch(s), he'll have more roaches than you and +1, and depending on the timing of his injects he could have some larva stockpiled already. Overseers are just too risky to be used in the early-mid-game, and later on when you may have some gas to spare, overseers are stopped by hydras or infestors. I just do not see any reasonable timing for this to be useful without being super-risky.
Oh, and Zenio won that match for reasons unrelated to the corruption spam. Idra's macro was actually totally fine regardless of the contamination. That game was also played during a different era of ZvZ when expanding in general wasn't as common. I would contest that nowadays, 90% of Zergs will have a 2nd hatch by the time those overseers show up.
I think that overseer's contaminate is a great strategy however...
Your primary focus/goal in a game should not be to get contaminate. Your goal should be to win the game and have fun. With that said, in ZvZ there are many ways of setting a goal to achieve at some point three overseers'.
"Oh, and Zenio won that match for reasons unrelated to the corruption spam. Idra's macro was actually totally fine regardless of the contamination."
Actually Idra's macro was walled into the ground because of the contaminate. He was unable to properly produce drones which lead to lack of roaches later on. This does not seem obvious because Idra kept his money low.
Contaminates power lies in your opponent trying to macro through. If you are consistently getting both hatcheries his macro will fall apart quickly.
The issues with contaminate is the cost of 300 gas. This is a significant investment of gas. The earlier you invest 300 gas the more vulnerable you make yourself (Due to lack of upgrades or rather the timing of when you can get them). As you use contaminates consistently, you will rapidly pull ahead due to lack of production. However you may still be vulnerable to a timing attack before you gain a "significant advantage".
The key may be to producing the overseer's one at a time, as you can afford the gas. Many times when you have your first overseer, your opponent will not have expanded. If you had produced three that early you run the risk of simply being thwarted over.
I think this would be a solid build if you used Contaminate in conjunction with a timing push. Also, if they get 2 queens at each base you are pretty much hopeless because two queens can easily down an Overseer. So if a Zerg gets two queens then you wasted all that gas which will probably lose you the game.
On February 26 2011 03:34 RageQuitter wrote: I think this would be a solid build if you used Contaminate in conjunction with a timing push. Also, if they get 2 queens at each base you are pretty much hopeless because two queens can easily down an Overseer. So if a Zerg gets two queens then you wasted all that gas which will probably lose you the game.
I think overseers are something you should pickup every game on ZvZ, not something you do a specific build order to get to.
My main problem is i think i just view ZvZ differently then you and we have conflicting opinions on the matchup. 7RR is a generally weak build in ZvZ,With a general 14 gas 14 pool opening the Z will be throwing down his second hatch relatively quickly, if you try and punish with roaches you are going to have mass lings thrown at you, which can actually be really hard for a one base roach strategy to stop because of quick two base ling production. An all in ling/bling response could also possibly kill you if you are trying to lair off one base.
If you are blocking your ramp with roaches, the other Z is going to sac an overlord to check for one base lair, and when he does he will be respond himself by moving up to a lair roach/hydra midgame off two base. Hydras come out relatively fast after lair and will be able to kill poking overseers relatively quickly either stopping the harass or forcing more gas to be spent on them.
Another thing to keep in mind is that the other Z will have been on two bases much longer if you one base lair, if the contaminate harass fails in the slightest he will be able to punish you hard or likely kill you when you try to expand due to larvae advantage.
Against another one base Z, the Z could likely have multiple queens, sheth did it in mr. bitters VODs and i believe another one of the players commented that it was for ramp blocking and also would help versus contaminate harass.
Generally im not a fan of funday monday strategies because of the general low levelness of the replays but i agree to contaminate is viable for lair midgame onwards, just not in a fashion that follows a strict one base build order to rush them.
EPT![[image loading]](http://www.starcraft2units.org/wp-content/uploads/Overseer.jpg)
![[image loading]](http://rtgamer.com/wp-content/uploads/2010/10/contaminate-lair.jpg)
![[image loading]](http://images.wikia.com/starcraft/images/a/a5/Queen_SC2_DevRend2.jpg)
