Power and Force in chess: the Value of a piece.

When we first play chess, we learn the “value” of the pieces. We learn that a pawn=1, a bishop or knight = 3, a rook =5, etc. On the chess site, in our games, these values are assigned for pieces captured.

This ‘value’ must be properly understood. It sometimes takes a while to gain an understanding of the true value of each of the pieces. Understanding the true and current value of a piece helps us to make wise choices in selecting winning lines and moves. So, let’s begin by discriminating between the value of the piece, the power of a piece and the force that a piece can exert in the game.

The value of a piece is based on a generalization. It can be likened to the number of squares a piece can control when on an empty chessboard. A rook will always survey fourteen squares on an empty board, seven on the rank and seven on the file, regardless of where it is placed. A bishop can control as few as seven and as many as thirteen, depending on where it is placed on the chessboard.

So, our first clue to the difference is to recognize that the placement on the chessboard is also a determining factor. The same must be considered in placement of the queen and the knight. On a corner square, a knight can only move to two other squares, but placed on it’s home square it can move to three, and as it advances toward the center of the chessboard, it surveys four, six, and finally eight squares (when placed on one of the center sixteen squares). So, a modifying factor to value is placement on the empty chessboard.

But, the chessboard is not empty during a game. The rook on its home squares protects the pawn directly in front and the neighboring knight, but has no other moves immediate prospects. At this time, every pawn exerts more force than either rook! The rook has little current value until it can exert its force on an open file. The rook in the corner has a potential force but an immediate negligible force. The value of the rook lies in the future in this instance. (Castling, usually thought to be a defensive measure, is an effective offensive measure to increase force by bringing the rook toward an open file.) The same is basically true of queen and bishops. These pieces need open lines in order to dominate; locked in behind pawns they still have their potential power, but they lack immediate force. So, with pieces and particularly pawns on the chessboard, the value of the piece depends on the positioning of other friendly and opposing pieces and pawns.

So, I offer you some differentiation of value: The value of a chess piece depends on its position on the chessboard and on the avenues open to movement. In general the value of a piece increases as it approaches the center of the board, and as that piece is able to use more lines and squares.

The opponents immediate position alters the value of our chess pieces. Only one of our bishops can take advantage of a hole or an outpost, and pieces attacking or restraining the opponent are momentarily increased in value.

But, that is not the whole story. The placement of the pawns strongly influences the value of any piece. The story of the ‘bad’ or ‘good’ bishop is an example. In addition, knights are controlled by pawn placement and lines are blocked or cleared by pawn placement.

Here is an example of a ‘good’ bishop against a constrained knight. The position is from a game Fisher-Taimanov, 1972:



White’s bishop is ‘good’ because it is not blocked by it’s own pawns, it has two fine diagonals and is now able to move to any of 11 squares. The knight is restrained by the white pawns and can only move to four squares, all to the rear. However, if the knight were on d6, it would be best placed. The white rook occupies a fine file, while the black rook is momentarily less active. Black would like to exchange rooks and bring his knight to d6, where it will complete a blockade by keeping the White king from advancing to c4. White is willing to swap rooks, but must first he needs to prevent the knight maneuver to d6.

Fisher Taimanov
1. Bb5 Rd6
2. Ke2! … White wants to retake with the king on d3, after the rook exchange. 2. … Kd8 Unpinning the knight.
3. Rd3 Kc7
4. Rxd6 Kxd6
5. Kd3 … If White can now exchange bishop for knight he will have a winning pawn endgame.



5. … Ne7
6. Be8 … Starting a sequence where the bishop ties the knight to defense of pawns, while forcing the Black king backward so that the White king can advance.
6. … Kd5
7. Bf7+ … Driving the king back so that White’s king can go to c4.
7. … Kd6
8. Kc4 Kc6

It is apparent that White has an advantage for two reasons: The bishop is stronger than the knight, and white has two waiting moves available in the b2 and c3 pawns.



9. Be8+ … The bishop is handling both the King and the Knight! Notice that black’s king is pushed backward, so that the White king can further penetrate the position via b5.
9. … Kb7
10. Kb5 Nc8
11. Bc6+! … A player could easily lose the chess game if playing hastily here; if 11. Bxg6?? Nd6++



The black king must give up either a6 or c6.
11. … Kc7
12. Bd5 Ne7
13. Bf7 Kb7
14. Bb3 Ka7
15. Bd1 Kb7
16. Bf3+ Kc7
17. Ka6



The White king has penetrated!, now to get the bishop to f7 or e8 to restrain the knight.

17. … Nc8
18. Bd5 Ne7
19. Bc4! … The bishop gains tempo enroute to f7
19. … Nc6
20. Bf7 Ne7
21. Be8 … Zugzwang!



21. … Kd8 Black has no other move…..

White went on to win the game. This bishop was remarkably powerful, certainly worth much more than the knight. If you look at real value, the position of the chessboard reduced the value of the knight and increased the value of the bishop. The bishop effectively dominated the chessboard.

So, let’s develop a convention for valuing any piece: The Value of a Piece can be expressed in a potential power, a latent power, which we can conveniently call the Power of the piece. This power becomes a kinetic factor as the chessboard empties. That is, this potential is normally reached as the chessboard changes in favor of the piece.
This Value of a Piece can also be expressed in kinetic power, the power of the piece at the moment, in this position. We can differentiate value by calling this condition Force. It is the immediate value of the piece. Power can be compared to a battery which has energy stored, and Force can be applied to the immediate application, such as turning on a flashlight, which puts the potential to immediate use.

This understanding is critical in determining the value of an exchange, we may exchange a potential power for an opposing force. Let’s look at an example:

Although a rook always has more power than a knight, here is an instance when a knight exerts more force than a rook, and a rook was given (“Sacrificed”?) to keep the knight.

This game was played in April 2006. Playing Black, I defended against a Reti Opening.
Here is the position after the 51st move:



Although the game has remained in the balance for the first fifty moves, Black has managed to limit one of White’s rooks with a pawn cage.

On move 52 white forks rook and knight. If the rook moves the bishop could be exchanged for an important knight, or white could play to free the caged rook and take a pawn in the process. This would leave white with the initiative and an impending attack.

Black observed:
Black had a better pawn position with an extra pawn and a passed a-pawn along with a potential advanced passed d-pawn. It was logical to play for an endgame where one of these pawns proved decisive.
One white rook was currently out of action, but both of black’s rooks were restrained. The rook is an offensive piece, and lines would have to be opened before either black rook could exert force.
The attacking white bishop had left the defense of the white king, and only knight and queen were left to defend the position against an attack by the Black queen, knight and bishop, while the rooks and bishop would be the attackers to support the white c-pawn to a queening. First, the Black b-pawn would have to fall.

Blacks plan, then, was to trade a rook for the attacking bishop, hold the pawn, trade black bishop for white knight and attack the white king while advancing the d-pawn. This line of play would give white a material advantage of rook against knight if the Black attack failed.

This is an example of a knight being worth more than a rook in a given position.

Here is the position after the 51st move:



White Black
1. Be6 … Forking knight and rook. When/If the rook moves to avoid capture, the attacking knight will be removed by the bishop, giving White a queenside initiative. .
1. … Rxe6! The rook gives his life for the knight.
2. Rxe6 … “Winning” the exchange.
2. … Nd2 Beginning execution of the plan. The valuable knight will support his queen in an attack.
3. Qc1 … White would now like to exchange pieces and get to an endgame with rook vs. knight.
3. … Bxd3 Removing an important pawn. The d-pawn is now passed!
4. exd3 Qxd3 Now, the d pawn has become dangerous, PERHAPS DECISIVE..
5. Ra3 Qe2
6 . Rb6 … White resigns, the Black d-pawn will queen.



Note that Blacks plan was carried out in only five moves. The valuable knight was much more useful than the constrained rook. A knight works very well with the queen in an attack,

The fact that the rook normally has a ‘value’ of five while the knight has only a ‘value’ of three was strongly modified by the position itself. The knight could exert more force more quickly than either Black rook. The mobile, attacking knight was, in fact, much more effective than either white rook.

To empower our pieces, to make them more valuable, and more effective, we cause them to develop force. We do this in the opening by quickly providing good lines for our line-going pieces, giving the bishops strong diagonals and using our pawns to deprive our opponent of best lines, while using our rooks on open files, and assuring mobility of our pieces by controlling the center of the board to the best of our abilities. In the chess middle game, we look for the development of pivot points through the center for our pieces, and for outposts for our minor pieces, particularly our knights. We block opponents lines and leverage lines open for our pieces. Throughout we want to maintain an initiative, forcing our opponent to defend against our threats rather than mobilize his pieces for attack. We should play to continuously increase the force of each of our pieces, on every move. Al

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