Zerg Upgrades vs Zerg

Finally, the last Guide detailing Zerg upgrades vs  Zerg. For those of you who are unfamiliar with this match up, it's a fairly Roach heavy match up, while both players expand and add on Hydralisks.  Zerglings are great in numbers early on, but against a Zerg with enough Roaches, Zerglings end up mulched. 

Banelings are even rarer (though not horrible as a rush), since they require another tech tree, and are horrible against Roaches.  Mutalisks only seem to work against beginners, as teching spire takes up a lot of gas, leaving you unable to defend from the enemy Roach army (and unlike BW's Mutas vs lings, Mutas take a lot longer to kill Roaches).

As always, I am only discussion Level 1 upgrades, because any benefit you gain is cancelled by your opponent's Level 1 upgrades (with the exception of the Roach, more on this below), and the benefit is re-gained when you reach Level 2 before your opponent. 

Alright so in my honest opinion, I think massing enough units is more important than upgrades for ZvZ. However, when you're on two bases with a very large Roach/Hydra army, you can definitely afford the upgrade.  Let's analyze which upgrade to get first: Level 1 Carapace, or Level 1 Missile Attack.

It takes a regular Zergling 49 shots to kill a Roach. Let's not forget regeneration, too!  And you wonder why ZvZ's are mostly Roaches...  When given +1 carapace, a Roach can take 73 shots from a Zergling before dying.  Hydralisks, being stronger, can take out a Roach in 15 hits, upgraded to 17 hits with +1 carapace.  For Roach vs Roach, it takes 11 hits to kill, and 12 with +1 armor.  This means a Roach with Level 1 carapace can definitely kill an enemy un-upgraded Roach.  A Mutalisk will need to shoot at a Roach 21 times before it can kill it (and thus, why Mutas are only used against noobs), upgraded to 25 shots with +1 armor.  Banelings, Ultralisks and Brood Lords kill in the same number of hits despite Level 1 carapace (9, 10 and 7 respectively).  Yeah, that's right, 9 Banelings to kill a Roach (well technically 8 brings it down to 1 health, so a Zergling can snipe).

Sounds good right?  Let's look at its attack.  A Level 1 missile attack upgraded Roach (Note: This gives the Roach +2 attack, so I will refer to it as a +2 missile upgrade)  can kill a Zergling in 2 hits, as opposed to 3 hits before the upgrade.  Against Roaches, the +2 attack lets you kill an enemy Roach in 10 hits (one less from normal).  But here's the kicker: A Level 1 missile attack upgraded Roach will kill a Level 1 carapace upgraded Roach in 10 hits, which is quicker than the 11 hits the +1 armor Roach needs (meaning it will kill first).  As great as that is, there is no benefit to the Level 1 missile attack upgrade against Hydralisks and Banelings though, still needing 6 shots and 2 shots respectively.

Well if we upgrade the Level 1 missile attack, Hydralisks get it too right?  As I mentioned earlier, Hydralisks kill a Roach in 15 hits, upgraded to 14 hits with the +1 missile attack.  For Hydralisks vs Hydralisks, the upgrade allows you to kill the enemy Hydralisk earlier, needing only 7 shots as opposed to 8.  Hydralisks kill the "Ling Brothers", both in 3 shots regardless of its attack upgrade.  Against Mutalisks, Hydralisks normally need 11 shots to kill.  With the +1 missile attack, this is upgraded to 10 shots.

Generally speaking, Level 1 Missile Attack seems to give an army of Roach/Hydra a slight advantage against the majority of Zerg Ground units.  So how does Level 1 Carapace help the Hydralisk?

Well a +1 armor Hydralisk can take an extra hit from a Roach (7 shots to kill, instead of 6), and since an un-upgraded Hydralisk will just barely die first to an un-upgraded Roach (take my word for it, I tested it once), that means the extra armor (or attack, really) will let your Hydralisk kill first.  A +1 armor Hydralisk will be able to take an extra hit from an enemy un-upgraded Hydralisk (9 shots to kill, as opposed to 8).

In general, by the time you've massed enough numbers, having your units kill faster may be slightly better than having them survive a bit longer.  Since Roaches are such great tanks already, I would argue that the Level 1 missile attack (which gives the Roaches +2) is slightly better to get first than the Level 1 carapace. Don't forget how the Roach gets +2 attack with each upgrade, which makes a big difference since your opponent "getting to Level 1 carapace" no longer nullifies your upgrade benefit.

Of course, my earlier suggestion of waiting till your economy is strong enough (and thus, massing more units earlier on) before you upgrade, also means that by then you should be able to get dual evolution chambers, and upgrade both at the same time.  Unfortunately, unlike BW, melee upgrade seems to be the least valued.

Before I finish, I want to suggest this replay.  It's a beginner SC2 ZvZ between two experienced BW players.  One player opted for early upgrades (He went Carapace first, then Missile) while the other player massed and stayed defensive.  Since it's a beginners game, the micro isn't the best.  However, theoretically, you would still expect the Zerg with the upgrades to be able to have the advantage.  Watch the replay to see the extent of theorycrafting, and how important it is to really apply knowledge into practice.

I'm sure many of you have noticed how I've left out Brood Lords (and Corruptors, I guess) and Ultralisks out of my write-up. In my next Guide, I discuss the usage of Ultralisks or Brood Lords, and will mention a bit of their upgrades there. Stay tuned!

Thank you for reading my Guide, and extra Thank You's for those who have read all my guides.  I do appreciate your comments and tips!