"Tactics is knowing what to do when there is something to do; strategy is knowing what to do when there is nothing to do."
- Savielly Tartakower (1887-1956)
Introduction
The origin of positional chess as a study dates only as far back as Wilhelm Steinitz, the first official World Champion of chess. Some earlier players clearly understood some of these ideas, but it was Steinitz who began to name the concepts and develop the theory. Steinitz called positional chess "scientific chess", and it involved concepts that are far less intuitive than the more straightforward tactical attacks that were the hallmark of chess up to that time. However, positional chess is not difficult to learn, given proper understanding and practice.
In short, positional play encompasses strategic ideas in chess. It involves seeing the board as a whole as well as the placement and interrelation of pieces.
There are various arguments about how to best play positional chess (or any chess for that matter), and the answer is not readily apparent, since each person thinks differently vastly different approaches are equally correct (or alternately useless). Therefore, I will not attempt to explain how to think, but instead to illustrate the concepts involved and the ideas behind them. At the end of this node is a list of recommended books to read, so if you are so inclined you can pick a method of analysis for yourself.
Note: The diagrams below are to illustrate concepts that may be misunderstood, but which can be easily shown to effect. Concepts that have no diagrams are either A. easily described or B. difficult to express concisely. This is, after all, a node and not a book.
Concepts
- The Center
The center is probably the most important positional concept as well as being the most easily understood. Control of the center (whether directly by occupation or indirectly by pressure) is vital to success in chess. The reason is very simple. If you control the center, you control the board. You can use the pressure there to obtain a flank attack, or you can place your pieces there to cause disarray in the enemy camp. The benefits of central control are numerous and fairly obvious. The center is generally defined as the four squares d5,e5,d4,and e4. (Diagram 1).
Diagram 1: Central Squares
+---+---+---+---+---+---+---+---+
| | | | | | | | | 8
+---+---+---+---+---+---+---+---+
| | | | | | | | | 7
+---+---+---+---+---+---+---+---+
| | | | | | | | | 6
+---+---+---+---+---+---+---+---+
| | | |XXX|XXX| | | | 5
+---+---+---+---+---+---+---+---+
| | | |XXX|XXX| | | | 4
+---+---+---+---+---+---+---+---+
| | | | | | | | | 3
+---+---+---+---+---+---+---+---+
| | | | | | | | | 2
+---+---+---+---+---+---+---+---+
| | | | | | | | | 1
+---+---+---+---+---+---+---+---+
A B C D E F G H
Weak Squares
There are a number of things that can make a square weak. The most common is moving pawns. When you advance a pawn, you leave weaknesses in its wake. Pawns cannot go backward, so each time you advance you create permanent holes in your defenses. The depth to which a square is weak varies wildly based on the position, but in the worst cases these weak squares can be controlled and/or occupied by enemy forces to devastating effect. Mitigating your long-term weaknesses while exploiting those of your opponent is fundamental in positional chess. Color weaknesses are generally defined as a weakness in pawn control on certain colored squares, often exacerbated by a loss of the weak color's bishop and/or the queen.
Space
Space is piece mobility. If your pieces appear to be more mobile than those of your opponent, it might be because you have more space. Space has been defined by some as your attacking potential on the enemy's side of the board. I'm not sure I agree completely with that assessment, since being able to maneuver easily and respond to threats in your own camp is easily as important as being able to move to the other side. This notwithstanding, generally if you have more controlled squares on the other side of the board, you have more space anyway. Maneuverability affects the ability to attack or respond to attacks, and trading pieces usually grants more space. So if you find yourself in a position with a favorable space advantage, try to avoid trades that might open up the mobility of your opponent, and, if possible, further constrict him or her until they are crushed. You should also usually attack where you have more space. This is typically the direction your central pawns are facing (Diagram 2). In the (exaggerated) pawn skelton diagram, white has much more space and should attack on the queenside.
Diagram 2: Space
+---+---+---+---+---+---+---+---+
| | | | | | | | | 8
+---+---+---+---+---+---+---+---+
|BP | |BP | | |BP |BP |BP | 7
+---+---+---+---+---+---+---+---+
| |BP | | |BP | | | | 6
+---+---+---+---+---+---+---+---+
| | | |BP |WP | | | | 5
+---+---+---+---+---+---+---+---+
| | | |WP | |WP | |WP | 4
+---+---+---+---+---+---+---+---+
|WP | |WP | | | |WP | | 3
+---+---+---+---+---+---+---+---+
| |WP | | | | | | | 2
+---+---+---+---+---+---+---+---+
| | | | | | | | | 1
+---+---+---+---+---+---+---+---+
A B C D E F G H
Unbalanced Minor Pieces
Minor pieces (bishops and knights) can be superior to each other given the aspects of the position. For example, a bishop which is blocked by its own central pawns is called a "bad bishop". If it is outside the pawn chain (and thereby not blocked), it is an active bad bishop and is much, much stronger. Often trading a bad bishop for a useful or active bishop of your opponent is a good idea. Likewise, knights can be very powerful if they can find weak squares to use as outposts, but can be extremely weak if you rob them of their advanced posts. In the endgame a bishop is generally superior to a knight if there are pawns on both sides of the board, due to its ability to guard or attack both sides of the board quickly.
Open Files, Semi-Open Files, and Diagonals
Open files and diagonals are natural homes for rooks and bishops, respectively. An open file is a file with no pawns remaining in it, and an open diagonal is the same, albeit diagonally. A semi-open file is usually defined as one in which your pawn is gone, but the enemy pawn on that file remains. Placing rooks on open files gives them greater mobility, which in turn increases their strength as pieces. Placing a rook on a semi-open file threatens the remaining pawn and places pressure on any enemy pieces attempting to use that file. The same is true of bishops, although to a lesser extent. An open diagonal can be a great area for a bishop to maneuver, attack, or reposition for greater effect. Opening and controlling the long diagonal (a1-h8 or a8-h1. Diagram 3) can be extremely helpful in many positions.
Diagram 3. Long Diagonals
+---+---+---+---+---+---+---+---+
|222| | | | | | |111| 8
+---+---+---+---+---+---+---+---+
| |222| | | | |111| | 7
+---+---+---+---+---+---+---+---+
| | |222| | |111| | | 6
+---+---+---+---+---+---+---+---+
| | | |222|111| | | | 5
+---+---+---+---+---+---+---+---+
| | | |111|222| | | | 4
+---+---+---+---+---+---+---+---+
| | |111| | |222| | | 3
+---+---+---+---+---+---+---+---+
| |111| | | | |222| | 2
+---+---+---+---+---+---+---+---+
|111| | | | | | |222| 1
+---+---+---+---+---+---+---+---+
A B C D E F G H
Pawns: States of Positional Interest
The various aspects of pawns are also of positional interest and many things can make them weak or strong. Sadly, and possibly surprisingly to you, gentle reader, pawns are one of the most complex concepts in chess strategy and each subject herein really deserves a node of its own. I will, in any case, attempt to briefly summarize the various states of pawns.
- Backward Pawns
A backward pawn is a pawn which cannot advance due to being unsupportable by other pawns, and which would be moving into an attack should it advance. See Diagram 4. The pawn on d3 is backward and cannot easily advance.
Diagram 4: Backward Pawns
+---+---+---+---+---+---+---+---+
| | | | | | | | | 8
+---+---+---+---+---+---+---+---+
| | | | | | | | | 7
+---+---+---+---+---+---+---+---+
| | | | | | | | | 6
+---+---+---+---+---+---+---+---+
| | | | |BP | | | | 5
+---+---+---+---+---+---+---+---+
| | | | |WP | | | | 4
+---+---+---+---+---+---+---+---+
| | | |WP | | | | | 3
+---+---+---+---+---+---+---+---+
| | | | | | | | | 2
+---+---+---+---+---+---+---+---+
| | | | | | | | | 1
+---+---+---+---+---+---+---+---+
A B C D E F G H
Doubled Pawns
Doubled pawns are often weak, but not necessarily so. If you have two pawns on the same file, they are doubled.
Pawn Islands
Pawn islands are any grouping of pawns which are no longer connected to the main pawn chain. Pawn islands are generally two or three connected pawns.
Isolated Pawns
Isolated pawns are pawn islands consisting of only one pawn.
Recommended Reading on Positional Chess:
This writeup is based on my 20 years of playing and reading about chess, so it's possible that I may have missed something. If you see anything that I overlooked, could clarify on, or just plain screwed up please let me know. Thanks.