I will structure my response based on my interpretation of 'who', 'what', 'when', 'where', 'why' and 'how'. 

Who

Who should have a repertoire?

Every player above 1000 should have some sort of repertoire, but the specifics will obviously vary at each skill level. At 1200 a repertoire of 'if my opponent plays this my pieces will go here, here, here and here to achieve x, y and z' along with knowing some basic traps is sufficient. But at 2200 you should be able to play at least two of 1.e4, 1.d4, 1.c4 and 1.Nf3 as White and have at least two defences to 1.e4, 1.d4, 1.Nf3 and 1.c4, knowing and understanding each line in enough depth. 

Who would benefit most from a repertoire?

A talented, judicious player could probably get by without a serious opening repertoire for some time, but I think once you break 1500 it is essential to have some sort of repertoire. A narrow repertoire will be of most benefit to a player rated below 1800, and a broad repertoire will be most beneficial to a player rated around 2400-2600. 

What

What is a repertoire?

A repertoire is a set of lines that you can play as White and Black against each of the opponent's main responses. 

What should be in a repertoire?

Ideally your repertoire should give you sufficient knowledge to reach a playable position against your opponents, and enough understanding to play good moves once you reach the end of your knowledge. Once you reach 2400 you usually need a number of lines that offer real chances of an edge as White and real chances of equalising as Black. There are exceptions but the majority of players at IM strength or above should play main lines. If you are rated over 1800 and have the time you should know how to play two of 1.e4, 1.d4, 1.Nf3 and 1.c4 and two defences to 1.e4, 1.d4, 1.Nf3 and 1.c4. 

What if I don't have the time to learn a repertoire?

Then you should decide on what openings you will play as White and Black, and whenever you play a game, analyse the opening phase to see where you or the opponent could have improved. Also make a note of any alternatives earlier in the game that appeal to you. 

When

When should I learn an opening repertoire?

Once you understand the general principles of opening play and need to know specific theory to come out of the opening with a playable position. 

When should I remove an opening from my repertoire?

Do not ditch an opening because of one bad game. I have seen too many players blame the opening whenever they lose a game! You should drop an opening when it is either not appropriate against the players you are facing, or when your results with it are well below your rating. Generally speaking it is best to keep your former openings as back-up choices, provided they are sound enough, in order not to waste the time you invested on learning these lines in the first place. 

When should I learn a new opening?

When you either need some more flexibility in your opening repertoire, when you want to understand a wider range of positions, or when you become stale with your current choice. 

When should I start looking for novelties in my openings?

In my experience, you won't get your own novelties on the board in your games until you become an IM, excluding of course correspondence chess. This is the reason most players are followers of opening theory rather than creators. 

Where

Where do I begin?

Start with the lines you will face most frequently, and work your way down from there.

Where can I find model games in my variations?

Go to Mega Database and create an opening report for the given variation to see who the leading experts of your variations are. Then study the games of the specialists in the line, especially annotated games.

Where should I practice my repertoire?

The best scenario is to have a training partner or friend who you play training games against in specific openings. But failing that, playing games online (and checking the openings afterwards) or using COW/Bookup to test your knowledge is a good way to learn your repertoire.

Why

Why should I have an opening repertoire?

To give you playable positions in the middlegame and enough understanding to play good moves once you are out of your book knowledge.

Why can't I find a low-theory line that is very strong?

The reason the main lines have the most theory is because they are usually the best moves. Of course there are lines that exist that are underestimated, but revitalising a sideline requires as much work as learning a main line in my opinion.

Why do I keep struggling after getting a better position out of the opening?

Maybe you do not understand the position, or you do not like the positions the arise. Try studying model games and typical plans, read a good book on the line, and if that still doesn't work, seriously consider giving up the line. 

How

It would take me a long time to answer the 'how' of opening repertoires - after all, Giddins wrote an entire book on this one subject.   

IMJohnCox wrote on 06/29/11 at 12:01:46:


I've only coached a few players in the one-on-one way that you mean.  I don't know if I should explain at length, but I will.

Every thing I did was as a volunteer at a local elementary school.  Most of my instructional time was devoted to what we called "Chess Team," which was a select group of 10-16 kids who met for 90 minutes in the evening once each week.  This was pulled out of "Chess Club" which consisted of two "ladders" of about 30 kids each, each separately meeting for about 1 hour during the school week.  "Chess Team" was the cadre of our scholastic tournament participation.

At "Chess Club" kids just played chess against a challenge ladder, though they might get a five-minute mini-less on this or that.  "Chess Team" received more instruction, maybe as much as 30 minutes out of the 90.  But for at least an hour, Chess Team played chess in a variety of formats: quads, team matches, "buddy chess" (make every other move; no talking to your buddy),"torture chess" (never touch your own pieces; announce your move in proper notation), five-minute chess, two-minute chess and so on and so forth.

Very occasionally I passed out opening notes at Chess Team, but mostly I just showed ideas on the demo board and expected the kids to pick them up.  I did expect the kids to play 1.e4 and to answer 1.e4 with 1...e5.  Only once or twice did a kid show an inclination to play anything else, and it was always because some chess dad decided to teach his kid to play the Sicilian or the Pirc or whatever.  I just told the kids, and the dads, to cut it out.  It was never much of a problem, I suppose because, A, I was a National Master, B, I was volunteering gobs of my time to the benefit of their kids, and C, our program always had terrific success in the scholastic arena.  Also, I suppose, in a team setting there's a lot of incentive to do things the team way.

The only one-on-one instruction I ever gave was to highly promising individuals that I selected from Chess Team; never more than two at a time and usually just one.  So in 17 years of coaching chess kids, I can count on my two hands the number of kids who received individual instruction from me at any great length.  I usually met these highly select kids at my house for an hour each week.

That is where I did indeed teach openings and did prepare tables of variations that I wanted the students to learn (like I said in another post, though, not usually very deep tables).  I had very scant trouble getting the kids to play what I wanted, except for one dad who was rated around 1750 and took a much more active role in his son's chess instruction that I wanted him to.  For some reason, he really took offense at my telling him that his kid had to drop the Sicilian.  He finally came around and became a big supporter -- but always, unfortunately, meddled much more than I would have wished with his kid's game.  In particular he was always on his kid's case to win more games and to spend more time studying and the like.  Once or twice I had to ask him to get off his kid's case.  But what can you do?  There are parents like that.   

I certainly wouldn't have donated an hour of my time each week to the private instruction of a chess kid, no matter how promising, who wasn't going to follow my advice.  But push never really came to shove. 

There may be other, better ways to teach chess, but that was the way I did it.  Maybe if I had encounted a kid such as you were I would've done something a little different, I don't know.  But never the Pirc, that's for sure.

John, I generally give my students pretty wide latitude when choosing their openings. As long as they can defend their choices, I'm usually willing to help them. For instance, I have yet to have a student explain in a meaningful way why Najdorf played 5...a6 in the Sicilian, so none of my students have used that in their repertoire. But I have had students play the Sicilian Dragon as Black. 

I do have many students who have come from other coaches. I rarely tell them to ditch their opening system, but I often try to steer them away from the passive Pirc lines that so many schoolchildren play because it keeps them from losing quickly. 

I have only had a few students play the Pirc as part of their repertoire, even though I know that many English GMs cut their teeth on that opening. (I'm thinking especially of Jon Speelman.)

It's very easy to guess who coaches many scholastic players in my area because of their opening choices. There are many students here who play the Dutch Stonewall because a local master teaches it. It is much more difficult to tell which students are mine just by looking at their opening choices. But I do prefer my students to play 1.e4 and in response, 1...e5.

Teaching is communicating. Communication requires the ability to listen. If the teacher is only dictating, the student won't learn as readily. So instead of telling the child that everything they are doing is wrong, I go out of my way to praise as much as I can of their game. 

If you had been my student, I may have steered you away from the Pirc, but you probably still would have played the English.

Mine has taken over a decade to get to where it is now, but it didn't start out as much.

I never had a coach, so I basically learned everything I knew about chess from playing games, and studying Nimzowitsch's books (I played through the games in Chess Praxis about half a dozen times since I kept picking up new things each time). I picked up from his games certain opening ideas that I could grasp, and made sense to me without knowing a whole lot of specifics. Initially these were:

1. Nf3/2. b3 and 1. c4 as white

and

NID/QID/French as black.

1. Nf3/2. b3 was basically a Reversed QID, so I was familiar with the general ideas - fight for the dark squares, control e5, improve the position around the outpost, occasionally undermine black's center with c4, or lock the position with e4 to help the kingside pawn storm, etc.

By understanding the ideas of what I was playing, I was able to develop my sense of openings from how they should look into the middlegame, and even into endgames. I didn't spend a whole lot of time back then trying to understand too much of the why, I rather focused on absorbing moves that appeared to be common in certain positions - over time I came to understand the why by osmosis by seeing variations from the common moves enough times to understand when deviation from the norm was good/bad.

That, and being somewhat competent at tactics was enough to take me to 1800 USCF, but then I hit a wall of sorts - my opponents were using more incisive methods against my openings, and I was no longer getting positions that were as good, so it was time to revisit my openings since I felt I could do more. Luckily I was able to acquire resources to study beyond the Nimzowitsch books at this point...

One of the players that "felt" similar to Nimzowitsch was Korchnoi, and I noticed a lot of his games in the English so I started looking at combining 1. Nf3/2. c4 since even at that time I decided I would rather get Queen's Gambits than 1. c4 e5 English lines. I began the very long process of mapping out all the transpositions, learning what lines had the potential for an edge, those that didn't, what lines I liked, how to avoid lines I didn't like as much, and so on. This was the real driving force to becoming a more universal player, as it forced me to address every major possibility at every point, because the desire was to put the pressure on the opponent by playing however was necessary.

On the flip-side with black very little has changed over the years. I fleshed out my knowledge of the QID/NID with all the minor lines I could try for practical purposes, and understanding why the minor lines are precisely that - minor. I added the QGD at a certain point because it's something I feel every chess player should know (studying the K-K matches left me with that impression). I also learned the C-K because I wanted an "equalizer" to the French's "counterplay", because the French often walks on egg shells when it comes to the theoretical aspect.

I don't think it's a "repertoire" that's necessary so much as being exposed to a lot of different positions, and putting the time into studying them. My "repertoire" as it is now is so broad that I have multiple choices against whatever my opponent uses - if a lower rated starts with a repertoire (assuming 1 line per opponent's opening) then the goal should be to expand the possible choices over time as part of learning.

Rapidly developing kids don't have the time to develop a complete repertoire (as they become stronger it's outdated before they've learned it) and others should do as they please.

I agree completely with Markovich. The initial question was impossibly broad, and I agree with his approach to teaching the kiddos.

I like to use the Ruy Lopez Morphy line to show how top players combine tactics and development to come up with the best opening moves. I particularly like to have the students work out why 3...a6 4.Bc6 dc6 5.Ne5 doesn't lose a pawn, and then ask after 4.Ba4 Nf6 why white usually plays 5.0-0. I then point out that when Black does play 5....Ne4, White doesn't play 6.Re1 or 6.Qe2, but instead opens more lines. 

(All this is after they've seen the Morphy-Allies game and learned the object of the opening isnt' to protect pawns but develop pieces, so this isn't so difficult for them.)

Most of my students will play the Spanish for at least a few months after these lessons and work on their tactical vocabulary rather than any opening repertoire.

kylemeister wrote on 06/28/11 at 18:20:30:


Yes, and I would also say neither is the Petroff unless you are well acquainted with the theory.

Uh, certainly the Giuoco Piano isn't boring for beginning players who have yet to learn/understand the most basic classical stuff in that opening.