What IS Opening Theory?

The following comments litter chess forums: "I'm looking for a low-theory opening" or "The Sicilian has too much theory" or "How much theory do I need to know to play X?"  Chess theory is a boogieman, overshadowing all our opening discussions ... but what is chess theory, and why do we care about it so much?

Many of these forum posts proceed as if theory is to be avoided as much as possible. On Monday, I gave an introduction to theory, at least as I understand it. Today, I'd like to suggest that this preconception with theory is largely misplaced.

The Definition

"Theory" refers to our knowledge of chess generally, which includes openings, middlegames, endgames, tactical patterns, etc. When most people use the term, they exclusively refer to "opening theory," and further, there's an assumption that "theory" = "the best moves."

Strictly speaking, a "theory move" is not necessarily the best move; it's simply a move that's been played (or analyzed) before.  You can load that position and see a previous game that was played (or a publication that has analyzed it to a conclusion).  When theory "approves" a move, that typically means games favour one side.  For example, 5.Bg5 in the Classical Sicilian, the so called Richter-Rauzer attack, has the best results for White, so it is the mainline theory.

The only move that applies any pressure to Black.

Chess is an incremental game, where our knowledge today builds off the work done yesterday. White tries a certain idea that works for a while, and then Black will find an antidote, and then White tries something new.  The cycle goes on and on, with yesterday's mainline becoming today's sideline... though frequently what was old becomes news and returns as the mainline with some sort of twist.

Theory is thus not synonymous with "the best moves."  Indeed, theory is filled with substandard moves. Further, in many cases, there is no "best" move; there are a variety of equally-approved options.

The Fear

Opening theory is thus a body of knowledge. Amateur players (and it's by far and away amateur players that discuss these matters) treat it as a mandatory body of knowledge.  "You must know the theory to play this opening," they say.  "It's very theoretical," they say. All of this stems from an underlying fear, the fear of getting caught out.

We've all been in this situation: our opponent plays super fast, his opening moves coming out like lightning.  There's something tricky about them, something not quite right.  We make a natural move and, bam, we fall into a trap.  "If only I knew the theory..." we think.

Over 100k people have fallen for this trap and counting.

Or we play an opening and our opponent plays a sideline.  We know it is a sideline.  We know it's not supposed to be good... but we don't know why.  We haven't studied it.  We play a few moves and reach a messy middlegame.  Our advantage is long gone.  "If only I knew the theory..." we think.

Or we play our favourite opening.  Our opponent plays right into our mainline.  We love it.  We go and we go ... and then we reach the end of our analysis.  We have to think for ourselves.  We misplay the resulting middlegame and only get a draw.  "If only I knew one more move..." we think.

In case it hasn't become obvious yet, let's do one more: we play Stockfish.  We've analyzed the 30 best moves in a given opening.  We play them.  We then reach move 31 and think for ourselves ... and Stockfish soon beats us.  "Must work on my theory..." we think.

I have a radical suggestion: none of these are opening theory problems.  Our fear and subsequent reliance on theory is completely misplaced.

The Opening is Still Chess

Buried deep, there seems to be an assumption that openings are somehow different from the rest of chess.  For example, White to move, what would you do here?  What is the best move?

What did you do?  Probably you evaluated the position, counted the material, determined the best and worst pieces, looked for threats, calculated some lines and then played your best effort. It's not an easy position and you might not find the best move, but hopefully you can at least find a good move.  You have to: you are all you got in chess.

Now what about this position.  What is the best move?

For a lot of people, the answer is, "It's theory."  The best move is hidden inside theory.  Either you know it or you don't.  Not only is this wrong, it's almost absurd.  Let's apply opening principles: we want to control the center, develop our pieces and castle.  Okay, let's do that.  What moves do that?

1. 6.Bg5, developing our piece to an active square?  Yup, good move.
2. 6.Be3, developing that same Bishop and reinforcing our Knight?  Yup, good move.
3. 6.Bc4, developing our other Bishop to the most active diagonal?  Yup, good move.
4. 6.Be2, developing our Bishop to a safer square, not at risk of running into ...b5?  Yup, good move.
5. 6.g3, preparing to develop the Bishop to g2 so as to control the d5-square more?  Yup, good move.
6. 6.f4, aiming to control the center more and gain more space?  Yup, good move.

Guess what?  Every move is theory.  Even without knowing theory we are following theory, just by playing logical developing moves!

You might argue, but wait, if this is theory, then Black will have prepared a response.  What should you do then?  At the risk of being radical ... it's the same thing as the first example: evaluate the position, count the material, determine the best and worst pieces, scan for threats, determine candidate moves and calculate some lines.

All the steps you do to find a good move in the middlegame or endgame still work in the opening.  The opening is still part of chess: the rules and principles still work.  The only difference is the focus on development; you rarely think about development in the endgame, just like you rarely think about passed pawns in the opening.  The focus changes, but the method for finding good moves?  That's universal.

At its core, opening theory is essentially the opening principles applied to the absolute maximum: how can I develop my pieces and control the center in such a way so as to place the maximum pressure on my opponent?  I know this sounds funny, but in many cases you can figure this out yourself.  And even if you don't get the absolute "best" move, chances are you will still find a good move.  In most positions, the logical developing moves are good (and often theory-approved).  You can rely on logic and principles to guide you through most openings, just like you can in the middlegame and endgame.

But I NEED Theory to Play This Opening!!!

First off, let's start with a hypothetical: weare against someone rated 300-points higher than us.  How much does theory matter?  Probably not much if at all: the other person is simply better than us, and they will likely win.  It's not because they know their openings better; it's because they are better at chess.

The same thing works in reverse: if we out-rate someone by 300-points, we win not because we have more theory but because we are more skilled. 

This holds true for all rating differences at the amateur level.  Even at an equal rating, where our knowledge could conceivably be the tipping point, games are overwhelmingly decided by differences in skill, not by opening study.

That said, knowing theory benefits a certain subset of openings more than others. I have played the Nimzo-Indian successfully with almost no studying; the logical, developing moves and common plans frequently work. Conversely, I am 0-3 in the Semi-Slav Botvinnik variation, where raw calculation matters much more. I should study this much more if I want to play it regularly, but I would wager the amount of positions you "need" theory is relatively small.

Some Final Thoughts

The number one complaint about learning openings?  There is too much theory.  The second biggest complaint?  How everyone always plays sidelines and never enters the mainlines.  How can both of these be true?  There's a world of theory you must know ... and yet never use?

How about this: we frequently blame our losses on not knowing enough theory ... but how often do we win because of theory?

Most players dread how much theory they need to learn and are always worried they don't know enough ... and yet we also assume our opponents somehow have perfect theory knowledge.  Isn't it more likely that most of our opponents have the same dread?

Most of our ideas and preconceptions about opening theory doesn't make sense when you look at them.

Fundamentally, I think there's a difference between "theory" on one side and "plans and principles" on the other.  The vast majority of amateurs don't need concrete theory, and learning it rarely helps.  Learning plans and principles of your opening, though?  This helps enormously.  If you know, for example, that in the French defence Black targets d4 and frequently puts his pieces on X squares and aims to either win the pawn or use that pressure to advance elsewhere on the board, this can guide your thinking regardless of what your opponent plays.  If you know the plans and ideas, you can play most positions well.  Maybe not perfectly, but you will play more good moves than bad moves.

The Mar del Plata variation of the KID has enormous theory ... but the plan is pretty simple: throw the pawns forward and play for mate.  The Sicilian Dragon has enormous theory ... but the plan is pretty simple: pawn storm and play for mate.  You can learn the essence of these positions quickly and then backfill the theory later.  Indeed, playing a few games with the right plan and then learning the theory is often illuminating.

I distinctly remember one such game: I knew I played the mainline, but I felt I had trouble.  Indeed, I soon got into a worse position, White got his ideal set-up and only divine intervention saved me.  When I analyzed the game after, I saw that theory recommends a different move order here:

4...Nf6, like I played, is natural but allows 5.Bc4, where the Bishop gets to its best diagonal (and I suffered because of that).  Instead, 4...Be6! stops this natural development and robs the Bishop of any useful square. This move made much more sense after experiencing my previous game, and I will never forget it (nor the general idea).

I can cite many more examples.  Theory frequently makes more sense after you have engaged with a position.  This is why many coaches recommend training games when learning a new opening; theory alone is not enough.  Indeed, the theory frequently doesn't make sense until you have played around with it.  Far from being something you must know, theory rather helps you understand the positions better.  It helps you grow.  And once you learn it this way, it's yours forever.

Conclusion

We frequently use theory as an excuse or as a crutch.  "If only I knew more theory..." For most of us most of the time, I wager theory rarely matters and is seldom the deciding factor in a game.  Treat the opening like any other chess position: use your understanding and thinking process to find good moves, and then use theory to confirm them afterwards. Supplement this with plans and principles specific to a certain opening. That is a much healthier and beneficial way to spend our opening study for the vast majority of us amateurs.