Evaluations are the basic tools for developing chess strategy. Goals and long-term tactics are the basis for future movements and the ongoing playing of the game. Each of the pieces at the players' disposal must be taken into account including pawn structure, king safety, position of pieces, and control of key squares and groups of squares. An example would be diagonals, open files, black or white squares all of which would make the opponents future moves possible.
Calculating the value of pieces on both sides seems to be the best chess strategy and is known as evaluation. Even though the point values used for this purpose are based on experience, it is usually found that pawns are worth one point, knights and bishops are equivalent to three points each, rooks are rated at five points, and queens are the strongest at nine points. The evaluation for the king, when fighting in the endgame, is approximately four points. Such factors, such as the position of the piece have considerable weight when decided upon the worth of each piece. For example, a pawn that has advanced is usually more valuable than one on its starting square. Also, coordination between pieces, such as a bishop pair usually coordinates better than a bishop plus a knight. In addition, the type of position (knights are generally better in closed positions with many pawns, while bishops are more powerful in open positions) is also a part of chess strategy and evaluation.
Pawn positions, structure or pawn skeleton is an important factor in the evaluation of chess position. Pawns, the most immobile of the chess pieces, causes the pawn structure to be relatively static and largely determines the strategic nature of the position. Chess strategy demands that the weaknesses in the pawn structure which can be caused by isolation, doubling or backward pawns and holes all be taken into account. Once created, these traits become permanent. Unless there is the definite possibility to develop attack tactics, one must take care to avoid these pawn structures unless they are compensated by another valuable asset.
How the pieces are evaluated
The basic chess strategy and tactic should involve gaining the opponent's pieces while returning one's own. In general, this chess strategy will be decisive in winning the game. This is especially true if the won pieces are of the more powerful sort.
The individual pieces have a hierarchical value rate: bishops and knights are basically equal in value, and both are less valuable than a rook. Rooks and the queen are called major pieces. In open positions, bishops are usually considered slightly better than knights, especially toward the end of the game when many of the pieces have been captured. The knights, on the other hand, have an advantage in closed positions. It is particularly good chess strategy to retain both bishops to act as a weapon, especially if the opponent has lost one or both of his bishops.
A rule of thumb as to the value of certain pieces would be:
In the middlegame – the knights are more powerful than pawns.
In the endgame - three pawns will probably be more useful than a knight.
Two minor pieces (bishops, knights) are stronger than a single rook - two rooks are slightly stronger than a queen.
A simple scoring system for chess strategy:
Pawn = 1
Bishop = 3
Knight = 3
Rook = 5
Queen = 9
"Winning the exchange" - This expression is used when one opponent gives up a knight or bishop in order to win a rook. The value is upped the value of 2 pawns. This turn of events does not take into consideration the current position and freedom of the pieces involved, but does provide a good starting point.
A pair of bishops can up their worth to seven points in some situations in an open position, becoming more valuable than knights; on the other hand, bishops will be less valuable than knights in a close position.
The king is invaluable: loss of the king equals the loss of the game.
Developing chess strategy always takes space into consideration. The more spaces occupied by pieces mean more power and advantages. Particularly in the center of the board, more long-term plans can be developed and options are more abundant. Both strategically and tactically, the opponent with more occupied spaces can exercise more influence. In some openings it will be to one player's advantage, however, to accept less space for a period of time in order to exercise chess strategy and set up a counterattack in the middlegame. Hypermodern play is based on this as well as other concepts.
Defense Chess Strategy
Aron Nimzowitch calls defending pieces which are not immediately in danger 'overprotection'. Nevertheless, each player should know that if not defended, the pieces located in the weakest positions will be overtaken by the opponent.
Opponents can allow pieces of similar value to be captured. One hostile capture deserves another, so to speak. Exchanging pieces gives the opponent with less occupied spaces something of an advantage in defending his remaining pieces.
This chess strategy of exchanging pieces will generally give the opponent less time to rebound. In the endgame any of the pieces may be the deciding force to claim victory; even a single pawn may make the difference.
Beginners may think that it is advantageous to conduct exchanges on a regular basis. The stronger player realizes that the middlegame is more complicated than the endgame and that is when the chess strategy of exchange will be more beneficial.
In certain instances, the 'exchange' refers specifically to rook, bishop, knight.
Particularly in the endgame, those pawns that stand strong against opponent's pawns and cannot be passed forward will remain in the game. The pawns on the sixth row have a value similar to a knight or bishop. Sometimes a meager pawn may make the difference between winning and losing a game.
The best chess strategy for a knight is to keep them in empty spaces or at the edge of the board where they cannot be threatened by enemy pawns, bishops and rooks. A knight based at the edge or corner seems to have less control, while a knight on the sixth level may actually be as powerful as a rook.
This piece moves diagonally only on the squares of its particular color. Thus it has controlling power of the other color. Pawns, for instance, that have moved to opposite-color squares can't protect the bishop and enemy pawns will end up directly facing on the vulnerable color.
An example of such a chess strategy, called finachettoed bishop, would be:
Bishop at g2 after pawn g2-g3 = strong defense for castled king on g1.
Pressure is exerted on the long diagonal h1-o8.
Giving up the bishop after a fianchetto will weaken holes in the pawn chain. The castled king will find safety impacted.
The value of a bishop is that of a knight. Sometimes it is more valuable, depending on the particular chess strategy circumstance. When there is 'room to maneuver', the bishop is stronger than the knight and can go longer distances. The knight, when in 'closed quarters' can hop over pawns and then that piece is stronger. In certain instances a player's own pawns will block the bishop on its color.
Especially in endgame, in open games with action along the sides of the board, the player whose bishop is free to move will stand a better chance of winning than the player with a knight.
The scope of movement on half-open files, where pawns of player's color are not found, is larger for the rook. Rooks are very good for attacking, especially pawns. Other pieces can only defend pawns, rooks can attack and guard the king very effectively. A favorite winning position involves having both rooks on either side of the seventh rank.
The chess strategy of Tarrasch: In middlegames and endgames with passed pawns, the rooks are usually the strongest when they are found behind the pawns and not in front.
The queen is the most powerful piece of the game. The queen can move in any direction and threaten all the pieces in her line of action simultaneously. Therefore the chess strategy of mating attacks involving the queen is easiest to achieve. It is advisable to send pieces such as knights, bishops and pawns into action before involving the queen to ensure her safety.
The best chess strategy of protecting the king in the middlegame is to keep it in a corner behind a pawn. If, however, the queen and rooks are promoted from the first rank, the king may be checked by the opponent's rook which may find it's way to the first rank. A luft, moving a pawn in front of the king, may allow the king an escape square but will weaken the king's mobility and position.
The king may find itself as the centerpiece and strong piece in endgame. If an immediate mate is not a concern, the king may be moved into the center of the board where he may make threats and influence following play tactics.