UC Berkeley StarCraft Class, Week 14 (Final Week)

In the last class of the semester for UC Berkeley's StarCraft class, several students gave their presentations.

Zergling Rush

The first student's topic was the Zergling Rush. The point of this strategy is to take advantage of Zerg's window of dominance at the very beginning of the game. Zerglings are weak, but you can get them out so early that your opponents might very well have little or nothing to defend with.

There are two main varieties of the zergling rush: the 4-pool and the 6-pool. 4-pool means that you only have four drones (resource collectors) when you build your spawning pool (the building that lets you produce zerglings). So you start the game by gathering resources for a bit, not building any drones, and going straight to spawning pool and zerglings. This is an "all in" strategy though. If you don't win with it, you are so severely behind economically, that you will probably lose. The reason to choose this strategy over a slightly more conservative 6-pool rush is if you think getting the zerglings to the opponent a few seconds faster will allow you to win the game on the spot.

The 6-pool strategy is still risky (putting you behind economically if you fail), but you can recover from it if things don't go as planned. The build order is to first build two drones (getting you to six total), then mine a bit, then build a spawning pool as soon as you can, then build another drone to replace the one that you just turned into a spawning pool, then build an overlord. If you do this correctly, these things will happen simultaneously: 1) your overlord finishes building, 2) you have all three larva ready to build units, 3) you have 150 minerals, the exact cost of building 6 zerglings from your 3 larva.

The student said the first goal of a zergling rush is to end the game immediately if you can. As soon as you arrive at their base, you probably have a good idea if this is even possible. If it's not, your next goal is to disrupt their economy. Remember that your economy is already disrupted by you doing a zergling rush (rather than building up your own economy) so you'll have to disrupt theirs just to stay even. If you can't disrupt their economy much, the next priority would be to at least force them to change their strategy or force them into a certain strategy. For example, they might have to build sunken colonies or bunkers right away to survive. And failing all that, at the very least you should harass with your zerglings and force the enemy to spend a lot of clicks to deal with you. The student also pointed out that there is some value in getting the opponent angry or flustered here, too. Zergling rushes are considered "cheesy" by some, so that's great to

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UC Berkeley StarCraft Class, Week 13

This week's StarCraft class didn't exactly go as planned. Students were supposed to give their final presentations today, but only one student who signed up for today was there to attend (the others preferred to fail the class apparently?).

The student that actually did present talked about strategy of containment in StarCraft. By his own admission, he is no top player, but did the best he could to understand when and how containment is useful and when it's not. He said he has about 150 APM and plays Protoss.

First, what does containment mean? It means trapping the enemy in his base, however you can. The student gave these advantages for using a containment strategy:

• Good for low APM players (like him). It usually doesn't take a whole lot of clicks to set up containment, but it can take a huge number to bust out of one.
• Takes advantage of superior flux. You set up your units just right (at choke points or in semi-circular formations) so that all your units will be able to attack at once while the enemy will probably not be able to accomplish that, given the terrain.
• Gives you map control. If the enemy is stuck in his base, you have free reign of the rest of the map so you can expand.
• Reduces the cone of uncertainty. If the enemy is stuck in his base, there's just fewer things he could possibly be doing.
• Reduces your scouting burden. Similar to the last point, scouting becomes less critical when the opponent is mostly stuck in one place.
• Stalemates help you. If you are containing the enemy, then there is a battle where both sides lose many units, even a statemate is acceptable to you. That's just more time going by where you can expand anywhere you want and the enemy cannot.

He listed these disadvantages to containment:

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UC Berkeley StarCraft Class, Week 11

This week's StarCraft class was about deception.

Professor Feng used these terms. leading up to deception:

Level 0 - Use micromanagement, macromanagement, look around the map for various map features, you aren't taking the opponent's actions into account.

Level 1 - Scout the enemy, build correct counter units based on what he has, position your army well given the position and direction of movement of the enemy's army

Level 2 - Deception and reading the mind of the opponent.

Two main types of deception in StarCraft are:

Army deception. Either a) get their defensive army to leave when it shouldn't or b) get their offensive army to attack at a stupid time or place.

Build order deception. Force the opponent to build the wrong units.

We already looked at one example of build order deception in a previous class. The Zerg player used an overlord to scout an expansion base, but was chased off so the overlord could only see the edge of the minerals at the expansion, rather than the whole base. The Terran player then sent SCVs from his main base to mine the expansion minerals to fake that he had an expansion. This caused the Zerg player to expand, thinking he was safe for a while when in reality the Terran had no expansion at all and a sizeable army to rush with.

Here are several more examples of deception. In this video, the Zerg player has 4 lurkers. The natural place to put them is at the top of the ramp, but he splits his force into 2 lurkers at the top and 2 before the ramp. He then puts the lurkers at the bottom of the ramp on "hold" but leaves the ones at the top in their usual attacking state so the opponent will know about them. This coaxes the opponent into gathering a large force at the bottom of the ramp (right on top of the two lurkers down there). Notice the amazing willpower of the Zerg player in the he gets an entire pack of marines right on top of his lurkers...but he still doesn't make them attack. Instead he waits until there are TWO entire packs and uses his mutalisks to bait them into standing in just the right (or wrong!) place.

Here's another similar example, also showing some willpower on the Zerg's part. The Zerg player allows the Terran to destroy his sunken colonies even though the Zerg could take his lurkers off "hold" and have them attack. When the last sunken colony is destroyed, he finally

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UC Berkeley StarCraft Class, Week 10

This week's class was about how to use APM (actions per minute). In other words, each player can only click so many times per minute, so he must make best use of those clicks.

Professor Feng divided APM use into three categories:

1) Incompressible. These things you just HAVE to do. If you don't do them at the times you should, you still have to do them, just later on when you remember or have time. Examples are building your economy, responding to harassment, and moving your army.

2) Compressible. These things you can do at your leisure. If you have some free moments, you can spend all your clicks on these things. If you have more important things going on, you can let these slide. Examples are scouting, micromanagement, and harassing the enemy.

3) Extraordinary. These things are above and beyond the usual. Examples were proxy (which I thought I knew the meaning of, but not sure in this context) and deception (will be covered in a later class).

I think the most useful idea of this week's class was illustrated by a graph that I will describe in words, rather than draw for you. Think of a graph over time that shows how many clicks you are doing at each moment. First, imagine the clicks that you need to do that come from building workers. Every 20 time units, or whatever it is, you'll click because of that. This by itself is not a big burden. But soon you will have enough money to build a gateway or other building that makes units. From then on, you must add a new set of clicks for building attacking units. Later, you have enough money for a second gateway, and this adds a new set of clicks to build attackers from there. So as time goes on, you have a heavier and heavier burden of clicking until at some point, you can't do it all anymore and you must choose what to do.

There's more to this though. If we look at the graph, we see that at some points in time, lots of things demand your clicks all at once. Maybe the time you're supposed to build a new probe is right at the time you also should build a gateway and right at the time you also should build a zealot out of some other gateway. So there are some points in time where your available clicks are pretty much maxed out. And these clicks are all *incompressible*. You must do them, so if you are slow, it just means you're taking longer than you should to complete the necessary task.

There are other points in time where you don't have to do any of those clicks. Maybe all the lulls line up so that you have a few moments where you don't have to build a probe or a zealot or a gateway. You can then do some scouting or harassment or move your army to better position.

The key idea here, the most insightful part, is that it's extremely favorable if you can use your *compressible* actions (the ones you do while waiting around between the super-important stuff) to harass the enemy in hopes that he will fall behind on *incompressible* actions. The basis of this theory is that harassment is extremely powerful and demands a counter. If I send a reaver/shuttle to your mineral line, you can't really decide to just ignore that and keep doing your incompressible actions. My one reaver can completely devastate your economy so you MUST respond. And even if you can respond and can completely stop my reaver, you are obligated to do so, even if that means delaying all your incompressible clicks, like building more probes, more gateways, more zealots. Because I can initiate harass during my "free time" and not fall behind on my important clicks, I don't get behind as much as you, because chances are you will need to delay your important clicks.

You might ask, "what if I happen to harass the enemy during his compressible time, so he doesn't get much behind either?" Sure that is possible, but remember that you are the one who initiated the harass, so you can choose to do this at the times most favorable to you, and chances are you'll catch the opponent at a bad time for him, at some point.

To summarize in one sentence: harassment lets you use your compressible APM to delay the opponent's incompressible clicks.

Next, we saw some examples where expert players manage to do compressible and incompressible actions "at the same time."

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UC Berkeley StarCraft Class, Week 9

This week was about countering the opponent. Remember that the main reason to scout (scouting was last week's topic) is to create the chance for you to counter the opponent.

Professor Feng said it's pretty obvious which units counter each other, so there's no need for him to cover all those specifics. There is actually a lot more to say about countering than just listing specific unit counters though. For example, let's say the opponent has 12 dragoons. What would be a good counter? A standard answer is speed upgraded zealots, maybe 14 of them. But then the professor showed us a replay of a match showing this exact situation where the *dragoons* win. In this case, the player controlling dragoons used an extreme amount of micromanagement to dance them around so that even the speed-upgraded zealots had to take lots of damage trying to reach any particular dragoon. After a bit of this, the dragoons get a lead and their superior number spirals to make the fight easier and easier for them.

So even though speed zealots would usually counter, the opponent can use micromanagement to survive the counter. What can yo do against an enemy who does this? The answer is to force him to run out of "attention" resource. Micromanaging the dragoons is kind of hard in itself, but there's no way he can do that while also defending against some other attack (or two!) in other parts of the map.

Scale

The next concept is the effects of scale on counters. The two examples were mutalisks versus marines+medics and vultures versus dragoons. Marines+medics are a "counter" to mutalisks, but only when the battle is of a certain scale.

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