Letting the opponent get an uneven advantage in a corner you are fighting for will help you lose.
Does this not apply for all places you are fighting?
And please prefer sides over the center.
Why should i prefer the sides over the center?.. Why not, instead of giving instructions; say something about why it's good to play those places.
It's not about it being easier to live, or how many stones it takes to surround. It is true, but those are just infered from the real reason. It's all about efficiency. If the player is told that that it is efficiency it is about, then they will think about why. And hopefully learn some of the fundemental concepts of go in the process.
Tamsin: It seems to me that thinking about the opening is always changing. "Everybody knows" that it is quickest and easiest to make territory in the corner and then the sides, and that moves in the centre have little territorial value. That said, at least up to high dan level, I'm sure that what really, really matters is understanding how stones work together. That is, you can play pretty much wherever you like with success if you know how to make use of the plays you have made. I'm sure that corners are the biggest opening moves, but just maybe they are not that much bigger than the sides after all.
Richard Cant: The reason for not playing moves in the centre is not that one does not want to make territory in the centre - it is rather than if you want to make territory in the centre in sente then the easiest way to do it is to play stones on the 4th line - next to your opponents 3rd line stones - forcing him to reply. Stones on the 4th line also make a larger centre territory than stones played higher up. (Of course, making centre territory is not the only use for a 4th line wall). Bear in mind also that a stone in the corner is not necessarily there to make territory. A 4-4 stone is there mainly for its central influence. (something beginners often fail to appreciate when trying to use their handicap stones!)
RobertJasiek: The parent page needs a major revision. Currently it teaches nonsense. 1) How easy it is to make life depends on several factors and not only on the place on the board. 2) How easy it is to make territory a) depends on several factors and not only on the place on the board and b) is in conflict to the amount of territory that possibly can be made. 3) Predominating tradition should not be confused with go theory.
Anonymous: Please note that this page has "introductory" as a keyword, in other words it is aimed at real beginners, say the 25k level. Discussions of how it is possible to play the first move almost anywhere on the board and not incur too severe a penalty is inappropriate. Talking about how to make territory in the center by attacking opponent's stones is not appropriate. A certain amount of discussion of efficiency is probably OK but 25k players aren't going to be able to tell whether stones are working together well or not. The corner-side-center paradigm is a useful guide for people who are almost completely in the dark about how to play.
RobertJasiek: I oppose keeping beginners dull. Even beginners deserve truths instead of falsehoods and can, e.g., easily understand that a center stone can get life easily by having 4 running directions.
Anonymous: I wasn't suggesting keeping beginners dull, just saying that we should be careful of giving explanations that are at too high a level. For example, how many times have we seen kyu level players say that they don't play through pro games or read the comments because they can't understand why the moves were made? If you give a 25k player an explanation suitable for a 10k player it is not likely to be very useful. If you write a discussion of correct go theory it is likely to be incomprehensible to beginners. A 30k player probably won't understand what the word "run" means as applied to a stone in the center.
RobertJasiek: So much we agree, but nevertheless the page can be greatly improved by lying less. Also keep in mind that the page title is believed proverb knowledge by many SDKs, i.e. the page difficulty level is misleading.
Tapir: Imo the page should get across one main point, edges are your friend. In the corner there are 2 helping edges, on the side 1, in the centre none. It is a very basic point about efficiency that isn't changed by the fact that many games are decided by fights in or control of the centre. (The advice starting with "SO" and "And" might be a little misleading. Maybe people get the wrong idea that being enclosed is ok etc.)
P.S. If anyone has trouble with a misleading sentence on a page, this is a wiki = please edit it directly. If there is a disagreement, we can start the discussion late, lamenting in the discussion hoping someone will change the page accordingly usually doesn't work out and is contrary how wikis are supposed to work.