Thursday, February 24, 2011

APM Theory

Whenever I play Starcraft 2, many questions are asked either from my friends or from my stream viewers, "Why do you make so many unnecessary clicks?" or more essentially, "Whats the point of having a high APM? (Actions Per Minute)". To be honest, the answer to that question is so convoluted that it requires you to study the theory behind APM and its correlation to your skill in any RTS (Real-Time Strategy Game). Luckily for those curious readers, I have decided to write an in-depth technical document that will most likely cover everything that you need to know about APM.

As I am a hardcore Starcraft 2 player, I will mostly stick to examples from it but the theory should practically apply in any RTS game you will encounter in today's world.

Before I begin, to eliminate any potential for nonsensical comments and/or trolls. I am certainly not claiming that I know everything about the Starcraft 2 or any RTS on the market, but I am establishing that I have some insight about the foundation of RTS games, especially Starcraft 2 to at least be able to talk about APM and its correlation as I am a 2550 Point Master Protoss player in North America server. You can confirm that here. I'm just trying to eliminate any pointless comments such as "tl;dr, he's bronze, he doesn't know what he's talking about, don't need to read".

1)Introduction - What is APM?

To fully understand the correlation between APM and any RTS on the market, you must first know what APM truly is. If you are 100%, without a shadow of a doubt, sure that you understand what APM is, you may skip this section.

APM stands for Actions Per Minute, and it measures the amount of actions made in any RTS games. For instance, if you selected your command center, that's an action you made. And then if you started to produce an SCV right after, you just made another action. And if you made a total of 50 actions in a single minute, then your APM is 50.

Of course, in most RTS games especially in Starcraft, your APM is calculated in every second by using a modeled predictive equation. In Starcraft 1, they simply took the number of actions made in each starting minute and then multiplied it by 60 to begin with, then divided the total number of actions made in each second by a decremental value of 1. In other words,

APM = (Number of actions made * 60) / Seconds Elapsed

Starcraft 2 has an equation that is slightly more complex but it is pretty similar. One thing to keep in mind for Starcraft 2 is that the APM measured by the game is actually weighted down a bit because the game is played at faster pace instead of normal pace (40% Difference) and if you make same commands in a row, it does not take the duplicate action into calculating APM.

So if your APM in Starcraft 2 is something like 200, then your APM in Starcraft 1 is roughly around 280.

2)APM and it's correlation to skill level

Now the fundamental question that most people were wondering: Is APM really important as to increase your skills in RTS? The debate on this topic has gone on for many, many times and is still raging on like a burning fire! So a caveat: there is no truly established answer for whether having a high APM will truly make your play effective or not. But I am not here to keep you bored: I will certainly present my personal hypothesis and back it up with a sound claim to hopefully convince you but if you want to dispute my impeccable and flawless claim, you are certainly welcome and I encourage you to do so!

There are two facts that are definitely clear and are undebatable: One is having a high APM doesn't necessarily dictate how well your play is going to be. The true question is how efficiently are you spending the APM you produce?. An analogy that I commonly bring up to associate this is studying for an exam: Just because you spend many hours studying for an exam, doesn't necessarily mean you will score high on the exam. But you sure as hell have a better chance, and this analogy practically summarizes the hypothesis that I am about to present on this thread.

Another fact that is undebatable: for professional gamers, having a high APM is a requirement and many years of trial and error along with statistical data have practically confirmed that you have much lower chance of winning against someone who has significantly higher APM than you. You may say that it is logically impossible to prove a case simply by using statistical data, even the result hits near 100% of whatever you are trying to prove (Which it is, in this case) and I agree with you. I will also add further details to this later on, but for now, our primary concern is to people who play games for entertainment purpose not to people who are forced to be the best of the best in the world to make living.

So then, I made a hypothetical chart in terms of what the correlation will look like.

Most of you probably saw this coming, but trust me, with the exception of professional gamers, there are a MANY, MANY KEYBOARD WARRIORS out there who will dispute this claim to death should they not agree with it. But what you see above is my personal conclusion and generally accepted hypothesis amongst Korean Starcraft portals (such as PlayXP).

Widely speaking, Starcraft 2's gameplay can be divided into three sectors. Liquidpedia does a pretty good job at summarizing this, so I will not go in depth of explaining these sectors. It's roughly divided as follows:
  • Mechanics
  • Information
  • Knowledge
APM obviously, mostly has to deal with the mechanics of the game: How well you micro/macro to gain information real time and apply the knowledge (strategy) you have to carry yourself to victory. Without mechanics, you will not be able to scout efficiently to gain information during the game and you will lack the ability to construct buildings and produce units in time to carry out your strategy as smoothly as possible. This is one of the biggest reason why I am an advocate of APM being increasingly important as your skill level increases. Hence, for most cases this should apply vice-versa: As long as you can maintain a high APM that is efficiently spent, this should be the foundation of improving your play as you will have access to utilizing strategies that may require you to have a certain level of APM. For instance, Boxer's infamous two rax push. Without having a high APM, it is without a doubt IMPOSSIBLE to micro those marines out of danger from incoming baneling bust.

Banelings Banelings Banelings Whoaaaaa!!!!!

In summary: The pre-requisite for acquiring and interpreting information and applying knowledge into the game is Mechanics or, your ability to micro and macro. Which directly links to APM.

3)Opposing claims, instantaneous vs average APM 

Opponents of the above mentioned claim will state that at low level, most notably from bronze to gold, having a high APM does not correlate to your skill level. A gold level player with 300 APM certainly has a chance of losing to another gold player with 60 APM, due to the fact that they are still at a stage where their knowledge about the game is low, so their capability of executing the strategy which requires high APM is minimal hence, most of the APM spent by the 300 APM player will result into massive amount unnecessary clicking.

I consider this claim to be blatantly false for the following reasons: One, the 300 APM player could've been executing the strategy he intended to without much flaws, not producing much unnecessary actions but the 60 APM player devised a ridiculous strategy that completely counters the 300 APM player's strategy. Since we are talking about gold level, it may be more fair to assume that this situation occurred completely out of luck but we cannot deny the possibility.

And usually.. it's these guys that makes those lucky counter-strategies work

Two, even at low level leagues, the players' understanding of the game along with their ability to react to situation will greatly vary. This is partially due to Blizzard's ELL (MRR) system not being perfect, not always matching you up with the player who's around your level but it's also due to the fact that all players have a different pace of learning. As an example, you probably have encountered a student earlier in life who barely studies but still scores high in the exams because he/she comprehends the material just by glance without having to review it. Call them genius, gifted, f**king fags, whatever you wish but this world is unfair- some people are bound to learn faster than others. And from this, you can infer that there will be a huge diaspora in terms of skill level even within that league. Of course, Blizzard continuously tries to minimize this effect by introducing new leagues and improving on their match making service but it's still imperfect.

So anyways, the point I am trying to make is the player could've lost the game simply because other player had a higher understanding of the game. The player could've already been a platinum or diamond material , for the particular match he/she was playing. The above argument has absolutely nothing to do with demonstrating how having a high APM failed at winning him the game.

The opponent of the claim may then attempt to make a counter-argument that if the above point were to be accepted, then you must also take into account the difference of how players understand the game even at high level. Although I view this as an extremely far-fetched generalized claim, if this point were to be accepted, yes this is certainly true. However, at high level games, we discern people who are very close to having a complete understanding of the metagame available to date and for them, just because your enemy has a slightly better understanding of the game than you, it isn't going to promise a win. Now, if the player can back up the given advantage to the player's favor with superior mechanics, then that argument is finally valid but then again, this presumption destroys the initial point which the opponent was trying to prove: how having a high APM doesn't correlate to your skill level.

Now the second argument that is a lot more convincing in my opinion, is that it's the instantaneous APM that matters not average APM. Hence, you should execute your commands without any spamming and instead be focusing on bringing your APM up in situations where it actually matters.

Even I am inclined to agree to this claim to a degree. However, after pondering for a while I've come to the following conclusion:

One, as your play level gets higher and higher, there will not be much difference in between focusing on average APM and instantaneous APM. At high level games, as the game progresses further, the game tries to squeeze more and more actions from you, so other than the beginning, there is no window of opportunity to spam unnecessary clicks.

Two, increasing average APM is bound to help instantaneous APM and help your gameplay. One of the leading argument for this case is "it keeps you focused in game", "helps you keep your own pace" and this is psychologically proven to be the case. Every action you take in life, your brain sends a pulse of waves that is in a certain frequency that if you try to synchronize your movements in a certain pace, it keeps your brain alerted and this is no exception for playing RTS game. In fact, extensive scientific research was conducted on this theory by comparing the brain state between a professional gamer and a casual gamer.

Three, the unnecessary cycle of clicks you make during the game can give you a valuable information in game if utilized correctly. For instance, I will make the following cycle of clicks in the beginning stage of the game:

  • Click Nexus
  • Click the probe scouting and pan the camera to it. Frenetically make queued up move commands.
  • Click pylon/gateway/cybernetics core or any building in construction
I make the selections so fast that it practically seems like it's purely meant for APM spamming but from this, you are consistently given certain pieces of vital information:
  • Click Nexus

    Is my Nexus producing probe? If no, produce one. If yes, how far is it until the probe is done? How much mana does my Nexus have that I can spend on chronoboost?

  • Click the probe scouting and pan the camera to it. Frenetically make queued up move commands.

    What did the probe scout? What build order is my opponent going? What unit composition does my opponent have that I will have to counter with? How many workers does he have in his mineral line? Did he take both of the gas?
    Would I have to queue up my move commands just in case if enemy units will engage the probe scouting while I am focusing on something else?
    Does my probe have full HP/Shield? Did it get harassed by a worker that I may have to watch out for not getting it killed?

  • Click pylon/gateway/cybernetics core or any building in construction
    How much longer until my pylon/gateway/cybernetics core done? Do I have enough mineral/gas to make the unit/tech structure I want to make? 
From simply cycling through the above 3 things, you can see what goes through my mind as I am consistently updated of all the information I need to have in the early stage of the game. Looking at it from the outside, it may seem like pointless APM spamming but you would have to be a fool to deny the importance of what I mentioned above.


Don't think APM is everything, but don't neglect it's effect on how it can improve your game. Playing an RTS game is like commanding a battle inside your head and your hands are replicating what you drew up in your head and without a fast enough hand to carry it, well then you sure as hell lack the leadership to lead your troops to victory.

So, players who are aspiring to be better I'm going to give you an advice: Start improving your APM. For Starcraft 2, if you can keep your APM above 150, you are doing a very good job. If you are not used to keeping your APM high, first you will make a lot of inefficient actions but additional practice will surely turn those actions into efficient ones. Bottom line is, you gotta start from somewhere.

I'm going to post the following video and end this discussion. Questions and comments are always welcome!


  1. Is there some sort of streatching tecnique that you can do so you can move your hands that fast? Because when I try my hands get cramped or stuck, or I just cannot reach the keys.

  2. Well you can try to wrap your wrist with a sandbag like moon did above OOLOLOLOL

    Nah, as he stated above the best way to do so is consistent practice and to set a goal for yourself which will gradually increase your APM. For example, if your average APM is 60, set a goal to increase your APM from 60 to 65 on your next game, then 65 to 70 and so forth. Gradually, your hands should be trained enough to get it up to the level you want.