Chess Primer: Understanding Chess

This post is intended to be read after Chess Primer: Basic Rules

Now that you know how the pieces move, and how to read chess gamescores, you will be able to play through recorded games, watch live ones, and of course play your own. When spectating however, the reasons behind the moves, and whether or not they are good moves, might not be clear. Who is winning and why? Unfortunately it is not easy to determine the answer to these questions watching a chess game, at least compared to more popular sports.

After all, you don't need to be a professional football player to know which team is winning a game; all you need to know is how to read the score. With chess, this is more difficult. Here, I'll show you some features of a chess position which often indicate one side is winning. These are things you should look for when you are looking at chess games. These positional features don't always confer an advantage, but they often define the struggle in the game.

Warning! The following two sections is my attempt to distill down a lot of chess knowledge into a handful of paragraphs. Despite my attempts to make this as concise as possible, I do apologize for the remaining verbosity and the length. In addition, the experienced player will recognize rampant generalizations. Keep in mind that this section is to be used only as a guide, and further study is encouraged.

Understanding Chess

Section I: Piece Power, Current and Potential

Section II: Pawn Structure

Section I: Piece Power, Current and Potential

Usually, the player with more pieces and pawns is winning. But there is also a great deal of times in which this is not the case. After all, not all pieces are created equal. In fact, the power of each piece can change between games, or even during the same game, depending on the position. Then how are you supposed to make sense of all of it?

Well, if there was an easy answer to that question, then we would all be on our way to becoming grandmasters. Evaluating imbalances in piece count and activity, together calculating ability, are probably the two biggest skills needed to improve (there are others, but I'd put my money on those two carrying a player far).

Chess pieces each have a different value; usually, a Queen is said to be worth 9 points, a Rook 5 points, the Bishop and Knight 3 each, and the lowly pawns are worth 1 point. You might be wondering who set these values. (It's not the Federal Reserve; they only handle interest rates) They are really the reflection of the potential activity of these pieces.

Pieces should be valued both in terms of what activity they have in the current position, as well as what kind of activity the pieces might have in the future. Piece activity is a bit tricky to define, but it is a combination of the scope of the pieces (how many squares it can move to) and the purposefulness of the piece (if it is attacking an important target or acting as a key defender).

As a rule of thumb, the following pieces are at their maximum strength.

1. A Rook on an open, or semi-open file (attacking a weak pawn or piece)
2. A Bishop on the long diagonal (either a1-h8 or a8-h1)
3. A Knight in the center of the board, at an outpost (where it is defended and cannot be attacked by an enemy pawn)
4. A Queen that is attacking something with support of other pieces.

Taking account the current activity of any piece is thus not too difficult do to (doing it with the precision of a grandmaster is another matter, of course). But what about potential activity? To understand this, consider the initial position. Most of the pieces (all in fact, except for the Knight) cannot move. They have no scope at all! However, after a few moves by the pawns, lines will be open for the pieces to enter the game and take up strong posts in the center of the board. The Rooks in particular, stuck in the corner, usually take the longest to enter the fray and participate in the game in a meaningful way.

Potential Activity

Thinking about the potential activity of a piece is thinking about how that piece might behave in five, ten, or even twenty moves down the road. In most games, pieces and pawns get captured and traded, and the board becomes less congested and there are less obstacles for pieces to move around. Thus, the pieces that have the greatest ability for travel (Like the Queen and Rook) will eventually be more valuable than the Bishop (which is restricted to a specific color) and the Knight (which lacks range). Even the lowly pawn can aspire to be more valuable, and usually grows in power as it gets close to the end of the board (where it can promote to another piece).

This consideration of the mobility and activity of a piece, especially in the ending, is more or less how the point system of 9, 5, 3, and 1 points are derived (But remember that even these values still partly depend on the nature of the position). When trying to evaluate which side is winning based on their piece activity, first you should determine if one side has a lead in potential activity (Chess players will refer to this as "Material") and then which has a lead in activity at the moment (Which can be preferred to as piece activity, initiative in some forms, or simply pressure). Many games are a battle between who has the better piece, and if a single piece can be shown to be more valuable than two pieces on the opposing side.

A word of caution: when thinking about piece activity, both current and potential, remember that the ultimate goal of the game is checkmate. Piece activity is not that meaningful or beneficial if it doesn't eventually contribute to that goal in some way!

Section II: Pawn Structure

... les Pions. Il sont l’âme des Echecs ... ... the Pawns: They are the very Life of this Game. - Francois-Andre Danican Philidor

(from chessquotes: http://www.chessquotes.com/topic-pawns)

One major aspect of Chess, as described above, is piece value and activity. Another very important aspect is the value of the pawns. After all, there are just as many pawns on the board as there are all other pieces combined. 

The particular arrangement of pawns, or the pawn structure, can often dictate the plans each side pursue. In addition, it is often the pawn structure that will determine which pieces have the potential for the greatest activity. Since pawns cannot move backwards, they can leave weak, undefended squares in their wake. These are squares in which enemy pieces will often infiltrate, increasing their activity.

Blocked Positions

Blocked positions are a consequence of the fact that pawns cannot capture the same way in which they move. In these positions, the pieces have less room to maneuver, and this often makes it difficult for certain pieces to find active squares. In the example shown, the pawn mass in the center limits the scope of the Black Bishop. This piece is not active, and it's potential activity is also diminished (since it will likely be a long time before it finds an active, attacking purpose on the board).

Pawn Weaknesses

In addition to dictating which of the surrounding squares are weak and undefended, sometimes pawns themselves require extra protection. This is the case with isolated pawns, or pawns that do not have pawns on adjacent files (either at the same rank or previous ranks). These pawns, when attacked, will require defense from the pieces, preventing those pieces from achieving their maximum attacking potential. A striking example, shown above, features another type of pawn weakness: doubled pawns. Doubled pawns do not enjoy the same mobility as other pawns. In the example, the doubled isolated pawns form a great target for Black's pieces to attack.

So, next time you watch a game or are playing one yourself, in addition to considering the activity and value of the pieces, pay attention to the pawn structure. Getting your pieces and pawns to work together, increasing each other's activity while keeping them free from captures and weaknesses, is important for playing good chess.