I have never studied opening theory. The closest I've gotten was briefly reading about several openings in books, but never memorizing or using any. While I haven't ever played in tournaments I have played strangers at conferences (where they had tables and chess sets out) several times and never done too badly.
All the questions on this site about opening theory have lead me to wonder:
How important is knowing opening theory and what major advantages would I gain my studying opening theory?
How important is knowing opening theory
Opening theory is basically the idea that there is a certain way a game should start. This assumption is based upon the crazy idea that you do not want to start the game at a positional disadvantage. In order to accomplish doing that, some players will figure out what move set they struggle against, and then look up the "book line" for it. Where would you go to look those up? Well, you could start here: http://en.wikipedia.org/wiki/List_of_chess_openings , but another good place to look is google or a chess engine if you have access to one. As for google, just search 1. e4 e5 2. Nf3 and google will show you the name of the opening, and contain a link to wikipedia for that opening's basic nuances.
To me, knowing opening theory is more than just memorization. I do not know all the names, but I do try to keep track of the relevant sets of moves that are considered to be advantageous for the lines that I play.
What major advantages would I gain my studying opening theory
Don't just study opening theory in general. Pick something you like, and study the ins and outs of just that one specific opening. You can move on to another one later if you wish, but do one at a time.
The benefits are numerous. Mostly revolving around the fact that the more of these famous openings you know and are aware of, the more that you will be comfortable transpositioning into them, finding traps, building sturdy pawn structures, and recognizing solid development plans.
Don't wear yourself out trying to learn all of them at first. Pick one that you like, and then go with that. Or pick a player you like, and go with theirs. A couple famous players: Fischer, Kasparov, Tal, etc.
First, let's make a difference between knowing how to play in the opening and opening theory.
You need to know how to play the opening. At first this means you need to know what your goal is in the opening (development, king safety, center control, preventing your opponent from reaching the same) and what that translates to in actual positions. Then you need to have some plan of which openings you want to play, and you must know what the strategic goals of each are, how to play them. Otherwise it's going to be hard to find good moves. After any serious game you should analyze it and figure out what went right and what to do differently next time, and that is true for the opening just as much as for the rest of the game.
On the other hand, opening theory is the almost scientific search for a White advantage. It is about specific lines and once it has been demonstrated that black can equalize in a certain line, opening theory stops being interested. Until the day that someone tries a move that hadn't been considered before and that does lead to a White advantage, until Black's answer to it is found... There are mountains of theory and it's impossible to know it all. If you know a lot of it, and you get it on the board, and it happens to be a line that Black hasn't equalized in yet, you might get an advantage. Which will be useless unless you are strong enough to convert that advantage into a win.
It can be fun to follow opening theory, and if you learn it you can play the first moves like the top GMs do and that is fun, but I don't think knowing a lot of it helps your chess results at all.
For instance, take this position:
[FEN ""]
1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Nf3 Be7 5.cxd5 exd5
Theory is not interested in this position, as it is a version of the QGD Exchange in which Black has it relatively easy, as he will soon be able to play ...Bf5 and equalize. Books on opening theory will tell you that if White wants to play the Exchange Variation, he should play 4.cxd5 and hold back the king's knight for now.
Sadler in his book on the QGD however notes that it is extremely important to understand positions like this really well, because he used to be beaten in these equal positions as Black again and again "as a young IM". Understanding normal positions is the key to understanding an opening. But they're not interesting to theory.
Let's follow Magnus Carlsen. He played 1.e4 e5 2.Nf3 Nc6 3.c3 a few days ago, the Ponziani. It is generally ignored by theory since Black has many ways to equalize. Then he just played chess, and eventually beat the #5 in the world. That's a lot of hours of studying theory saved.
Work to understand the normal positions in your chosen openings, by playing through instructive games, playing them and analyzing them a lot. Don't memorize theory.
[FEN markdown that you used. Never seen that before.
As stated in the “how to learn them” question :
I don't hold a very high opinion of opening theory, and tend to advise¹ most people to care a lot less about it, and rather improve their actual thinking and play. If you get a decent enough position out of your opening, then the fun begins (and that's where it incredibly helps to understand what theory got you into, what you're playing for, and what you should keep an eye on, etc.)
It is not very important, at least before you reach very decent a level (I'd say around 2100 Elo, ymmv.)
Playing through your favorite openings, you'll learn them on the way. Once in a while, your no-knowledge will make you fall into a trap you won't fall in twice, or give you not so good a position because of a particular line or move order you weren't aware of, but altogether, development ideas and patterns, piece activity, and strategic principles as a whole will go a long way.
Supposedly, while you're not studying opening theory², you can still learn something else improving your game ? (I strongly suggest reviewing your games and learning from your mistakes.) That will do a lot better.
¹ Of course, this is only meant to hold for people my advice is worth something for. I'm sure it doesn't apply anymore past some level, but then, people tend to ask these questions less, unsurprisingly.
² In fact, I strongly suspect opening theory is so much studied because it's so easy to study³. Strategic principles you're forgetting or misunderstanding, judgement, and tactics are a lot harder to “study”. But a lot more important nevertheless.
³ Just learn lines and lines by heart, “they're theory, that can't possibly be wrong !” Only if you don't know what to do with the supposedly better position your book leads you into, the whole process is quite pointless don't you think ?
Once you get beyond a certain point, you'll suffer from the time lost considering opening moves that people otherwise at your level have memorized, along with the implications for the future positions. Before you get to that point, it doesn't really matter--practicing tactics is far more important (if you want something to practice). Just my opinion.
Learning opening theory as practiced by leading grandmasters is not necessary. What is necessary however is developing your own opening repertoire, whether those openings are in vogue or not. You don't need to read books to do this: just play the same openings consistently. Soon you will learn which openings lead to positions you like, and which don't, and based on this you can hone your repertoire.
In my opinion, learning opening theory becomes important if you want to get a high Elo rating (2100+). Indeed, when you play against a strong opponent who knows opening theory, you risk falling into the traps you don't know or memorize (and just lose the game).
I think that even Magnus Carlsen (who is a genius) needs to learn opening theory because he plays chess against players who know opening theory.
But I don't think you need to learn theory in all openings; you can concentrate efforts on two openings (one for white and one for black) you prefer to become a strong player with.
worth learning theory - by that, I mean general principles in the opening. Understanding what you are doing and why. Not theory as in memorising book, in my view, for most players.
Instead - learn tactics and endings, first and foremost. And middlegame positional ideas. And pawn structure / pawn power.
The problem with learning book is this:
you think you are stealing a march on games, but really you're not.
it is a Very inefficient way to get better, as it takes ages, and
subject to change and fashion. (People might not ever play these
lines in future!)
General principles will inform how to play the opening, and ward off needless breaking of these principles. But still break them sometimes, it is more fun and adds to the artistic experience. Also useful for psychological expediency, of course.
You can get to about 2000 with no knowledge of theory at all and probably about 2300 with very limited knowledge as long as you have a firm grasp of opening principles and are strong in the other areas of your game. .
Above 2300 the game is much different. Your opponents aren't going to make many mistakes very often so the advantage out of the opening (or lack thereof) will determine the game to a large extent.
