How to learn openings systematically?

I have some basic questions if someone will be patient with me...

One of the common pieces of advice for improving one's game is to learn and study openings.  I confess that, though I'm not a rank beginner, my eyes still glaze over when someone mentions any opening by name.  What makes it worse is that there are zillions of openings.  So I am constantly wondering what defines an opening, how many I should study, how many of them are actually just variations on other openings, and above all how to study them?

I started reading a primer on openings, but sort of gave up (I might start it up again) because, well, it didn't seem very efficient.  Besides, the author wasn't really defining what the openings were.  He'd just start talking about games without saying, "This precise sequence of moves is the Ruy Lopez" or whatever.  Like I can figure out how far into the game is "Ruy Lopez" and what, after that, is variation.

Also, why should I learn the main line?  Why should I play it?

Is there a really good book or essay or video (on this site even) where all these mysteries are revealed?

If that's common advice, it's bad advice.  Most beginners don't need to start studying the intricacies of opening theory because they don't have the tactical or strategic foundation needed.  Much more important is to follow the basic opening principles:

1.) Stake a claim in the center, either by occupying it with a pawn or attacking it with pieces.

2.) Develop your minor pieces  (bishops and knights) before your major pieces.  The kingside knight almost always goes to either f3 or (much less often) e2.  The queenside knight almost always goes to either c3 or d2 (more equal that f3/e2).  Since this is true for most openings, you usually want to develop a knight before you develop a bishop on the same side.  It's harder to tell where a bishop belongs than a knight.

3.) Don't move the same piece more than once in the opening, unless you have a clearly good reason (winning a piece, e.g.)

4.) Don't move more than one or two pawns before your development is complete.

5.) Get that king out of the center and castle.  This also helps connect your rooks.

I'm doing these from memory, so I may be missing one or two.  If you follow these opening principles (and you're no longer dropping pieces due to simple tactics), then you'll probably find that you're following the mainlines of some opening or another.

Once you're well versed in the opening principles you can learn one or two openings each for white and black, maybe the first 5 or 6 moves.  As you play those openings regularly, you'll see what tactics and strategies are usually used in them.

1) Play a chess game.

2) After you finish the game, look up the opening and see where you varied from the "book" lines, and try to understand why the book line is better.

3) Repeat steps 1 and 2 a bajillion times.

Well, I didn't mean to say that beginners should study openings.  Those opening principles, for example, are old hat for me.

What's the fastest way to look up the opening and book line?

Also, I haven't played many games on Chess.com, and those games were last year.  I'm a lot better now.

Thanks for the book recommendation.

Well, as I said, choose maybe one or two openings and play them.  As post #3 said, look up your games to see where they vary from the book line and try to figure out why the book line is better.  Openings databases such as the "Opening Explorer" on this site are good for that.  Beyond that, learning any opening "fast" is just going to leave your understanding patchy, at best.

Wikipedia is also a reasonable source (usually) for looking up the main lines and basic ideas of an opening.  But really, the only good way to learn an opening is to play it a lot so you get a feel for what thematic moves usually happen.

Lemmie take a stab at helping you. Let me say right up front that I suck at chess. My opening general knowledge is much better than my opening execution.  But that said, I, in spite of all the "don't study openings as a beginner" love screwing around with different openings and have tried most of them. All that out of the way, here we go...

First off, you will need three main opening "families." Something as white, something as black vs. 1. e4, and something as black vs. 1. d4. Eventually you will want something against the "oddball" openings too, such as the English, The Bird, etc., but the three I mentioned will take care of most games.

That said, unless you are a titled baddie player, there is no "best" opening. There are comparatively "sound" and "dubious" but for the most part, anything is playable at lower levels.

Now, when you look at an opening, we are going to look at it as "best for YOU." This is because each opening has its own style and objectives to some degree. Ask yourself these quesions.

1. What kind of game are you looking to play? Do you want a wide open tactical fracas? A slow, tense strategic struggle, where one pawn break may decide the whole thing? Looking to trade down to a good endgame?

2. Which is more important to you, stout defense, or sharp attack? You can get one or the other, but rarely both in the same opening.

3. Are you looking for something simple and easy to learn for right now, or do you want to bite the bullet and learn something you can use forever?

4. Are you more comfortable with a classical approach (pawns in the center) or a hypermodern one (pieces control the center from afar)?

That said, you really don't need to bother "learning theory" very deep right now. Most of the time your opponents will not play theoretically correct anyway. What you want to do is learn what the goal is of your opening, and how to execute it. For example, the French defense is about counterattacking in the center. The KID is about a kingside attack. etc. 

From there, I would just advocate trying things out. Hop on blitz or bullet and try a variety of things.

Three good resources: Chess mentor on here (if you are diamond) walks you through the opening phase of most openings, explaining why each move fits in the opening strategy. Good way to get your feet wet.

Most major openings have youtube videos that walk you through the opening.

And you can usually learn what the general strategy is by either looking at the wikipedia article about it, or an article here on chess.com

Another point, then I'll stop...

Often, you can, to some degree, cut your work down by learning openings that have similar styles. For example, I play the English as white (1. c4) and the Accelerated Dragon as black (1. e4 c5). These openings have almost identical strategies and goals, and often similar move orders, while of course, being a move up or down can change things. Against 1. d4, I play the dutch, which is similar, just on the opposite side of the board. This would be much easier than trying to play the Ruy Lopez as White, and the Sicillian and the KID as black, as those openings have very different strategies.

Anyway, have fun!

Have a look at this (excellent) article, and make it 2-3 hours. 

FCO is an excellent read too.

As for defining moves in the opening, you can find them in the opening explorer.

Fantastic responses, thanks to everyone.  Now I've got some things to do and think about!

I hadn't really known "how to look" at resources like http://www.chess.com/openings/ and now I have a better idea.  I think i can use that to at least memorize what the "big" openings are.

Also, thanks for the FCO pointer.  Nice reviews.  That must be one of the next things for me to do...

the question is rather if you learn from books how do you develop your repertoire yourself with new lines and improvements.. how do you do that??

I think the 4 volume set of Chess Opening Essentials is good for most people. It  gives you an idea what you should look for in the Openings, not just moves to memorize. I bought the set last winter, and think they are very good.

MCO-15 is a good one volume opening "dictionary" for you, if you want to buy it. A cheaper used copy of MCO-14 will be just as good for now. You don't memorize endless reams of opening analysis, just start playing the openings you like and study them a bit before and after each game if possible. Your opponents will also force you to study other openings, or else learn how to avoid them if possible. Try playing as few openings as possible and try playing them as both White AND Black to learn them. Finally, skip BS openings like Kings Indian Attack which are intended to cut down on having to study a bunch of openings, the KIA is positional and you  need to learn tactics and open games first.

CHESS OPENING PRINCIPLES by SIX FAMOUS GRANDMASTERS

Lasker's rules for the opening (from Common Sense In Chess)

1. Do not move any pawns in the opening of a game but the King and Queen pawns.

2. Do not move any piece twice in the opening, but put it at once on the right square.

3. Bring out your knights before developing your bishops, especially the Queen's Bishop.

4. Do not pin the adverse King Knight (ie. by Bg5) before your opponent has castled

GM Reuben Fine on the opening:

1. In the initial position White, because of the extra move, has a slight advantage. Consequently:

2. White's problem in the opening is to secure the better position, while...

3. Black's problem is to secure equality.

Fine's rules for the opening

1. Open with either the e-pawn or the d-pawn.

2. Wherever possible, make a good developing move which threatens something or adds to the pressure on the centre.

3. Develop knights before bishops.

4. Pick the most suitable square for a piece and develop it there once and for all.

5. Make one or two pawn moves in the opening, not more.

6. Do not bring your queen out too early. 7. Castle as soon as possible, preferably on the king's side.

8. Play to get control of the centre. 9. Always try to maintain at least one pawn in the centre.

10. Do not sacrifice without a clear and adequate reason, eg.:

* it secures a tangible advantage in development * it deflects the opponent's queen

* it prevents the opponent from castling * it enables a strong attack to be developed

Fine's two last questions to be asked before a move is made:

* How does it affect the centre? * How does it fit in with the development of my other pieces and pawns?

Nimzovitch's Seven Axioms (from My System)

* Development is to be understood as the strategic advance of the troops toward the frontier line (the line between the fourth and fifth ranks).

* A pawn move must not in itself be regarded as a devloping move, but merely as an aid to development.

* To be ahead in development is the ideal to be aimed for.

* Exchange with resulting gain of tempo.

* Liquidation, with consequent development or disembarrassment.

* The pawn centre must be mobile.

* There is no time for pawn hunting in the opening, except for centre pawns.

Suetin's four principles for advanced players

* The fight for control of the centre * The striving for the quickest and most active development.

* The creation of conditions that permit early castling.

* The formation of an advantageous pawn structure

GM Hort's 13 rules for all players

* Take advantage of every tempo. * Develop flexibly!

* Do not make pawn moves without careful planning.

* Begin the game with a centre pawn, and develop the minor pieces so that they influence the centre.

* Develop harmoniously! Play with all your pieces

* Do not make aimless moves. Each move must be part of a definite plan.

* Do not be eager for material gain. The fight for time is much more important than the fight for material, especially in open positions.

* A weakening of your own pawns may be accepted only if it is compensated by a more active placement of your pieces.

* With the help of your pawns, try to get an advantage in space and weaken your opponent's pawn position.

* Do not obstruct your pawns by grouping your pieces directly in front of them; pawns and pieces must work together.

* During the first few moves, pay special attention to the vulnerable KB2 square on both sides.

* Remember that the poor placement of even a single piece may destroy the coordination of the other pieces.

* With White, exploit the advantage of having the first move and try to gain the initiative. With Black, try to organize counterplay.

GM Portisch on forming a repertoire:

"Your only task in the opening is to reach a playable middlegame."

SOURCE: http://exeterchessclub.org.uk/content/ten-rules-opening