If the student doesn't know how to think correctly he will never be able to play very good chess. Even if he studies much theory, reads many chess books, etc. - WGM Yelena Dembo
In his book The Inner Game of Chess GM Andrew Soltis wrote: "A popular view among amateurs is that grandmasters ... routinely see 10 moves ahead. There are, of course, examples of this by GMs, but they are relatively rare. Much more common is the kind of calculation that calls for seeing not more than two moves into the future".
Not all masters agree on how one should advance but one of the best ways is playing over lots and lots of games. Not games by weak players and I’d avoid today’s modern GM’s. The reason is that they’ve developed a style (for various reasons) where they are often willing to make positional concessions for practical chances because of modern day fast time controls. Thus their games can be confusing and difficult to understand. I’d recommend games of classical masters. Even better are tournament books. Books of “My Best Games” are just that…best games. Better are games where you see GM’s whipping up on IM’s or IM’s pummeling Masters. You see all the warts that don’t make it into game collections and realize not all games by very strong players are masterpieces worthy of print.
Opening theory is fascinating to lower rated players and Fine’s old Ideas Behind the Chess Openings book is still one of the best to get acquainted with the general ideas. However this is not the way to increase playing strength and will actually hinder your advancement if it’s the main thrust of your study program. FM Pelts and GM Lev Alburt in Comprehensive Chess Course (Vol II): "We beg students who are addicted to opening manuals to remember that most players who spend their time studying theory never reach A-level."
Each opening has (or should have) a basic middlegame strategy behind it and all variations will be designed to carry out that strategy. If a move does not fit into the correct strategy, it’s probably not good. This brings us to the point that in order to really improve you must increase your positional understanding, tactical awareness and endgame knowledge. You have to supplement that by playing games AND playing over hundreds of master games. All this is designed to increase chess knowledge in general. That way when a opponent plays something you are not familiar with you will have some idea of the basic strategy and can judge how his move fits in (or not) and have some idea of where to start looking to plan your own strategy. Chess is not three different parts, opening, middle and end. They are all related so your opening should flow into a middlegame with a clearly defined strategy.
Wisdom from GM Nigel Davies: “Players who understand how to play Isolated Queen's Pawns, Gruenfeld/Catalan positions, Hedgehogs or King's Indian Structures never go through the much reported agonies of club players who attempt to memorize things.The last couple of days I've actually found some time to study some chess, printing out 35 selected games in a particular opening and playing through them with a board and pieces. The next step is to look at some details...
This is why it's good to be a generalist, whereby you have more patterns to draw on in any new situations and then draw multiple comparisons. People are often surprised by my ignorance of variations ... but the same is true of many GMs, IMs and just good club players. But if you have a good knowledge of various middlegame positions you will know what to go for and should be able to position your pieces well in the opening.
On the other hand the mnemonic approach to chess openings will leave a player disorientated as soon as something he hasn't studied comes along. And this ALWAYS happens, either when your opponent varies from your line through ignorance or because he cooperates to the VERY END.”
Studying openings in depth is overrated by lower rated players. Opening knowledge will not be of any benefit if your middle and endgame play is weak. Knowledge of opening theory may only mean the difference between an equal position and a slight advantage or disadvantage unless you are a master.
Most players don’t know why they lost a particular game. They blame a blunder, missing a move by their opponent or any of a hundred excuses. Usually there is a whole list of reasons: attitude, bad strategy, missed tactics, but often it’s failure to understand the basics. Most books are about openings. The reason is because most players are not interested in anything else. They are not interested in how to plan or how masters calculate, or endgame theory. Despite their claims most players are simply in a hurry to win a quick game and move on to another. Just look on any Internet site and it’s not unusual to see players with a hundred or more games going at the same time. How can one play that many games at one time and devote sufficient time to each individual game to play it well? They are the same players who buy opening books that promise them they will win more games if they play a particular opening. They will study tactics until they can do the exercises fast and accurately then complain because they still miss them in their own games.
Most players think that they already know chess basics, so why spend the time learning them again? But Jeremy Silman has discovered most players fail miserably and lack the understanding of basic fundamentals. They have problems with a lack of understanding concerning the purpose of the opening, no knowledge of planning and the thinking processes, no understanding of elementary endings. Nor do they understand how the opening, middle game and ending are related.
Here’s the list of books I learned the most from (most are long out of print):
Modern Chess Strategy-Ludek Pachman Taught me how to handle each piece and situations they operate best in.
100 Selected Games-Botvinnik
Reshevsky's Best Games-Reshevsky
These two books taught me how to apply what I learned in Pachman’s book. I learned much about all phases of the game including the openings I played. These are the first chess books I had.
Tarrasch's Best Games-Reinfeld. These are games of the "classic" style and it was one of the much maligned Fred Reinfeld's best books.
Modern Endgame in Theory and Practice-Griffith. Learned endgame basics from this well-written book.
Search for Chess Perfection-Purdy. A potpourri of easy to understand advice and instruction explained in a clear, concise manner, well annotated games and a bio.
The Road To Chess Mastery-Yermolinsky. Wish I’d had this book 50 years ago. No phony promises but he tells you how to study. This book should be a classic but it’s not likely it ever will because Yermo doesn’t make any promises or offer any quick, easy solutions. What he advocates is work.
The Art of Bisguier Vol 1&2-Bisguier. Great games by a colorful player.
Super Nezh-Damsky. Nezhmetdinov’s games are just fun to play through if you like attacking chess, or if you don’t they are still great fun to play over. If you like Tahl, you'll like Nezh.
My Best Games-Tartakower. Another colorful player with fascinating games.
500 Master Games-Tartakower. Classic games arranged by opening.
Never read any "beginner" books, opening books or books on tactics. The latter two came much later. I just started off studying best game collections and strategy and a little of endings, especially K&P and R&P. My approach back then was totally opposite to that of so many players today, but it must have had some merit because my initial rating was 1667 and it never went any lower.