UC Berkeley Starcraft Class, Week 2
Thursday, February 5, 2009 at 11:12PM Week 2 of the class was better than week 1 because most of the administrative stuff was out of the way so more time could be spent discussing StarCraft itself.
This week was about units. Professor Feng started by explaining that units are your eyes, ears, and hands in the game. Units give you vision through the fog of war (eyes) and are they are what you use to perform actions such as attacking, repairing, building, moving (hands). What he said we might not realize is that they are also your ears. He mentioned one match where the famous player Boxer put an SCV kind of near some minerals to scout, but it was actually the sound effect for gathering minerals he listening for, rather than the sight the SCV provided.
The next topic was something I refer to as local imbalance, though that term wasn't used in class. Explained in my terms, a game is supposed to have global balance (Zerg vs. Terran for example) but it's supposed to NOT have local balance, or it would be too boring on homogeneous. StarCraft has massive local imbalance amongst units and that is a very good thing.
One example was siege tanks. The longest range Protoss ground unit is the Reaver, with range 8. Zerg have lurkers of range 6. But Terrans have siege tanks with range 12(!) when in siege mode. This is a massive "imbalance" in that it gives you an advantage the other sides don't have. That is not to say there is any design problem (it's a strength of the design, not a problem), but it is to say that you have to recognize what exact situations and unit combinations are completely slanted in your favor so you can play to get into those situations.
Feng then asked us to name any Terran melee unit. Firebat? No, it's splash damage. SCV? No, they can't attack under Dark Swarm. There are no Terran melee units, he said. This was just to show that local imbalances swing the other way if you need to fight on the ground under a Dark Swarm.
Next, he asked us "What unit are you afraid of from Protoss if you are playing Terran?" Someone immediately yelled out Carriers. He then explained how good a cloaked Wraith would be against Carriers. Of course, your opponent knows this so your opponent has Observers to reveal the cloak of your Wraiths. He then examined the Medic's abilities, explaining the function of Flare. Flare blinds units and also turns off their detection abilities. Putting all this together, he said, you could use Medics to Flare all the Observers, then attack the Carriers with your cloaked Wraiths.
Here is a video of Boxer doing just that. (Is this a Boxer appreciation class?) Notice that he actually sends in just one Wraith initially, as a test of whether the Carriers can see it. They can't so he sends in the rest.
Feng then talked about damage types and sizes. As you probably know if you've played StarCraft, units are classified as small, medium, or large and attacks can have classifications of concussive (good against small, bad against large), explosive (the reverse), or normal (full damage vs all sizes). He then pointed out that Zerg's Sunken Colonies deal explosive damage and asked us to think about the implications. Most early units are small, while later game units tend to be bigger. That means Sunken Colonies actually increase their effectiveness as the game goes on. (Yes I know that's a simplification because of things like air units and siege tanks, but you get what he meant.) He said we should note though that units can upgrade their damage (zealots for example), while turrets can't (they only get a defensive upgrade).
Feng then asked us to think about how seeing some of the enemy's units gives you information. Not only what they attack you with but what they DON'T attack you with. A specific tell to look for is how much gas their units cost. You usually have some idea how much gas the opponent has, and if he sends wave after wave of units that don't cost any gas, then you can guess what's next. Feng asked, "If your opponent sends wave after wave of Zealots at you, what do you think is next?" One student answered "more Zealots" and I thought to myself that would make a good Rose player in Street Fighter Alpha 2.
Next, Feng asked us what would you do if you've reached late game, the map's minerals are mined out, your only units are a single drone, some overlords, and one defiler. Your opponent has one Wraith. Furthermore you have only 47 minerals, and 38 gas. One student said "I would type gg," which Feng accepted as usually a good answer in a case like that. But he showed a video of just such a situation.
The Wraith attacked the Drone. In moments, it would die. Before it did, the Zerg player put the Drone inside an Overlord, just to buy a little bit of time. He then used the Defiler's Dark Swarm many, many times in a row as a way to transport the Drone safely to a gas mine. With swarms everywhere and temporary protection from the Wraith, the Drone mined enough gas to build Scourge, then used the Scourge to kill the Wraith. This made the game a draw instead of a loss. Here's the video:
Someone asked how this happened and Feng explained that the Zerg player also had a pack of Ultralisks, but they were worthless because the Terran could fly his buildings around, preventing the Zerg win. The Defiler actually consumed one to keep up the Dark Swarm barrage.
Yosh then took over and showed us several examples where a player attacks in a way that is designed to get an advantage but is specifically not intended to win the game. The first was a reaver drop with a shuttle, 1 reaver, and 1 zealot. The shuttle landed the enemy's base right by the minerals, and adjacent to the enemy's one siege tank. The tank went down almost instantly, and the reaver tried to kill as many SCVs as possible while the Terran player scrambled to move them to safety. I cringed as each SCV died, because losing any of them, not to mention all the time lost where none are mining, is deadly in a game of exponential economy. Several died, at least 5, before the Terran was able to surround the reaver with SCVs and kill it.
Yosh then asked us if the Protoss player intended to win the game with this move. It's certainly possible to, and it's been done before. But we know that he really didn't because at the same time, he was building an expansion. Yosh said that if the Protoss player was serious about winning right then and there, he would have invested in more attacking units, send those too, and not put the resources into expanding. The player's actual choices were very good though. The attack did serious damage to the Terran while leaving the Protoss player with good economy.
The next example was a Protoss player who sent 2 corsairs around the map. What was his objective? Obviously not to win the game on that move, but to scout. It wasn't only scouting though, Yosh explained. The corsairs were able to fight a couple overlords, so the Protoss player gained more than just scouting information. Also, the Protoss player knows that one of Zerg's strong moves in this match is to build a bunch of Mutalisks. The Corsairs were really looking for a Spire to see if the Mutalisks were coming or not. If they *were* coming, then having corsairs is a already a headstart on countering the Mutas, so he thinks that's what the Protoss player was gambling for. No Spire was seen, but it seems that the Protoss player's actions were sound and his gains were good.
Next he showed us an example of the Mutalisk stacking bug. By making a group of Mutalisks with one (far away) Overlord in the same group, a bug in the StarCraft game engine makes the Mutalisks stack even more exactly on top of each other than they normally would. This also lets them attack simultaneously, as if it's one big attack. Yosh showed us a match where a Zerg player sends his stacked Mutas to the Terran base. Does he expect to win off this attack? No he doesn't. What he finds is a pretty well defended Terran base with turrets.
The Zerg player circles the Mutas around the base, going for containment. The Terran will not be able to leave the base while the Zerg player expands to a second (or even third) base. But as the Mutas fly around the Terran base, they find an opening and are able to take out a few Terran units. The match goes on to show some cat-and-mouse play with the Mutas, some are lost, but the point is made. They harassed, they contained, they destroyed some units, and they allowed the Zerg player to expand without trouble.
Yosh's final example was a match where the Terran player sent 3 Vultures and 3 Siege Tanks to the enemy Protoss expansion base. Before doing this, he scouted and gathered enough information to believe that attacking early would probably be favorable to him. He did not know exactly what was in the Terran main base though (which was up a ramp). Anyway, he sent the attackers, clearly having Vultures in assigned to one hotkey and tanks to another hotkey. As he arrived, the Protoss player pulled all his expansion probes away, up the ramp to safety while mobilizing 4 Dragoons to fight the Terran units. The Terran player quickly laid spider mines everywhere to control space around the expansion, then attacked the Dragoons. The Dragoons were forced to retreat up the ramp to the main base. The Terran was then able to destroy the expansion base.
Yosh said the whole thing was executed very well by the Terran, but he pointed out two improvements the Terran might think about. First, if he had driven his Vultures ahead quickly at the start of the skirmish, he could have laid the spider mines in a way that would have basically forced the Dragoons to get hit as they retreated. The vultures would then have been able to actually kill some of the Dragoons. Second, Yosh believed that it would have probably been a better idea to bring 3 SCVs to the fight. At the very least, these SCVs could repair the tanks during battle. They can also act as a wall to buy for the tanks as the slow dragoon shots hit them (or float around them due to strange bugs with Dragoon shots). Also, the SCVs could then stake out the territory by building turrets or whatever else.
Anyway, the Terran player didn't bring SCVs and what he did after the battle, I found very interesting. He left. That's right, he just turned around and went back to his base. I have spoken much about "pressing the advantage," but in this particular situation, it does seem that leaving was a smart choice. Yosh referred to this as "accepting the advantage." The Terran could have pushed up the ramp and tried to win right there, but it's really uncertain how that would pan out. He could have lost all those units that way, or he could have gotten lucky. He didn't have the main base scouted and even if he did, 4 dragoons and a ramp can go very wrong for you. Instead, he let the game play out, knowing that they would end up in a 3 base to 2 base situation, with Terran advantage.
Finally, Feng took over again and showed us a video about how 3 Marines can cleverly avoid all damage from a Lurker by making the Lurker attack, then moving to avoid the linear attack, then briefly firing and repeating. This is very, very difficult (impractical in a real match to do it to the degree shown in the video) but it shows a concept you can use a little bit here and there in a real match.
He said that studying small details of the game like this is very important and it's how people in the class can contribute to the StarCraft community. As parting words, he gave an offer. Sometimes when a Dragoon shoots at an SCV, the shot misses completely. Maybe it's something to do with the SCV turning at just the right moment, he doesn't know exactly. He said if someone can show a way to make a Dragoon miss at least 50% in this situation, that he will give that student a passing grade for the entire class.
That's all for this week, and it was a lot. Did you actually read it all?
Reader Comments (67)
I'd still say yomi has a relatively important role in SC, obviously scouting gives you better information than yomi can ever give, but what you scout isn't always true either. I've just been looking at the finals in GomTV's tournament and there are several examples in those games where the two players will give the other false information (or at least attempt to. It isn't uncommon to research range when the scouting peon (or whatever) is in their base, only to cancel it in favor of their real tech, or hiding a tech in some corner of you base/the map.
I recall one in one match at the blizzcon finals (I think it was 2007, maybe 2006) where NalRA would build a pylon just behind the mineral line at the twelve o'clock's natural who's only function would be to throw his opponent off his game as there would be a missing pylon in NalRA's main, which would then indicate that he was doing a proxy somewhere (he wasn't).
Obviously this is very different from the yomi in SF where you simply cannot know what your opponent will do next. Partially because you have all the information you'll ever get right there, and partially because the premise of the game is completely different. But saying that yomi doesn't play a huge factor in SC because there's a different application of yomi would surely be wrong.
About "Accepting the Advantage":
Couldn't it be argued that falling back after successfully taking out an expo (and thus secure an economic lead) could be considered pressing the advantage due to the slippery slope in SC? You're obviously not pressing your offensive advantage, one you'd be hard pressed to do given the ramp, but you are working on your economic advantage.
"Couldn't it be argued that falling back after successfully taking out an expo (and thus secure an economic lead) could be considered pressing the advantage due to the slippery slope in SC? You're obviously not pressing your offensive advantage, one you'd be hard pressed to do given the ramp, but you are working on your economic advantage."
To me the reason it's not pressing the advantage (and it's all really just semantics) is that regardless of your choice to offensive push or not you're going to be expanding your eco. Sure there's the limit of attention but from the other in game resources there's nothing limiting you from going up that ramp with your current force and expanding out your eco. You're taking the current advantage you have and staying there allowing the slippery slope to do it's thing rather than pressing up the ramp to further the advantage right then and there.
Just something i have to say, after i looked at the posts following my first comment:'
Some of the comments seemed to think that i was arguing against Rekrul's post, but as much as you guys hate that post, and as much as you dislikes his bad manners, this guy is a former PROGAMER. That, is a guy, who knows his s**t and has a much more indepth knowledge of Starcraft, than pretty much anyone at TL.net, and it's highly unlikely that anyone here even comes close to his understanding of the game. I'm not trying to offend anyone, but the fact is, that to understand RTS is not the same as understanding Starcraft.
Second, I will say, that while yomi does exist in Starcraft, it isn't anything like SF. In Starcraft, yomi is one big guess (build-orders), and several small guesses (where to harass, where to defend, where the opponents exposed science vessels are etc.).
It is essentially only the build-order that can be a loss if you doesn't guess correctly, and even here yomi only exists, when the players have studied tons of replays from each other, and prepared furiously for the match. Other than that, it's a blind guess, because you mostly play against people you don't know online. So, if you play against friends or at a top-level tourney, build-order-yomi DOES exist, otherwise not.
And even if you technically suffers a "build-order loss", you can always come back in the game(like iloveoov vs boxer, see my previous post), even though it will be hard.
The other type of yomi, the tactical, where and when to attack or defend, where to harass and so on, can be minimized by studying the maps you play on, knowing the best placements of antiair, looking at the routes dropships usually fly, and with sufficient tactical knowledge, the best places to defend, the best places to push in to grap the high ground, or how to utilize high ground to shred apart an incoming force.
All in all, yomi is NOT something that Starcraft players uses hours and hours to study or practice, because there are so many more important facets of the game.
And BTW: please don't hate on Rekrul, he's a very intelligent guy, despite his bad manners.
Slivaz signing out.
"So, if you play against friends or at a top-level tourney, build-order-yomi DOES exist, otherwise not."
This isn't anything new. Lots of random scrubs are hard to predict in SF2 because they pull the moves they will do next out of a hat and do them with no regard to anything else going on in the game, like spacing, the odds that the move will hit, or what will happen if the move fails. There will be situations where you have to throw Yomi out the window and just play to what's on the screen. Generally Yomi comes back into the picture at high-level play. Yomi isn't necessairly the be-all end-all of strategy, either.
"The other type of yomi, the tactical, where and when to attack or defend, where to harass and so on, can be minimized by studying the maps you play on, knowing the best placements of antiair, looking at the routes dropships usually fly, and with sufficient tactical knowledge, the best places to defend, the best places to push in to grap the high ground, or how to utilize high ground to shred apart an incoming force."
Let me grab on sentance from that:
"looking at the routes dropships usually fly"
USUALLY!
That sounds a lot like Yomi to me. Yomi definitely occurs situations where there is an "optimal" position, and then a counter to that position that requires the player to forgo the "optimal" position in order to survive.
There is a lot of strategizing on both sides before each match. Pro starcraft players have whole teams of coaches that help them out with watching the replay and deciding how to play against a specific player on each map. In this part the Yomi might not be done during the actual game, or even by the actual player. Still sounds a lot like Yomi though.
"That, is a guy, who knows his s**t and has a much more indepth knowledge of Starcraft, than pretty much anyone at TL.net, and it's highly unlikely that anyone here even comes close to his understanding of the game. I'm not trying to offend anyone, but the fact is, that to understand RTS is not the same as understanding Starcraft."
I keep hearing this argument that "Starcraft is not just an RTS!" It seems to me that some people have the belief that:
"Oh, Starcraft is so complex and incredible that it cannot be defined by any one genre, or by anyone! But except by the people who are really good at it because they understand it somehow."
I think that Starcraft is the best RTS to date, but it's still an RTS. You control units in real time. You do not have to aim these units beyond telling them what to shoot at, nor do you have to go through the motions of each unit's movement, you just give them the orders and they do the rest for you. Anyone who says Starcraft isn't an RTS is getting way too caught up in semantics. I understand it's way different than other games in the genre, but it is still within a genre.
I think it's easy to understand the fundamentals of Starcraft, really. The game tests your ability to make quick decisions and the ability to split your attention between many things at once while still doing them all with a sufficient execution level. It also tests your overall strategy and Yomi abilities at time. What else would you say Starcraft measures other than traditional strategic abilities, the ability to make quick decisions, the ability to divide your attention, and the ability to read your opponent and see through any tricks he might be doing?
and one there isn't a fancy name for that I'd call "only a Dune 2 champion is allowed to make any statements about Dune 2."
Elitism.
Hey Sirlin, did you get to lesson 3? If so, will you write another summary of it? I would really appreciate it :)
and one there isn't a fancy name for that I'd call "only a Dune 2 champion is allowed to make any statements about Dune 2."
Argument from authority.