Chess strategy
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- This article uses algebraic notation to describe chess moves.
Chess strategy is concerned with the evaluation of chess positions and setting up goals and long-term tactics for future play. During the evaluation, a player must take into account the value of the pieces on the board, pawn structure, king safety, position of pieces, control of key squares and groups of squares (e.g. diagonals, open files, black or white squares), and the possible moves the opponent will make after any move made.
The most basic way to evaluate one's position is to count the total value of pieces on both sides. The point values used for this purpose are based on experience. Usually pawns are considered to be worth one point, knights and bishops three points each, rooks five points, and queens nine points. The fighting value of the king in the endgame is approximately four points. These basic values are modified by other factors such as the position of the piece (e.g. advanced pawns are usually more valuable than those on their starting squares), coordination between pieces (e.g. a bishop pair usually coordinates better than a bishop plus a knight), and the type of position (knights are generally better in closed positions with many pawns, while bishops are more powerful in open positions).
Another important factor in the evaluation of chess positions is the pawn structure or pawn skeleton. Since pawns are the most immobile and least valuable of the chess pieces, the pawn structure is relatively static and largely determines the strategic nature of the position. Weaknesses in the pawn structure, such as isolated, doubled, or backward pawns and holes, once created, are usually permanent. Care must therefore be taken to avoid them unless they are compensated by another valuable asset, such as the possibility to develop an attack.
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[edit] Basic concepts of board evaluation
[edit] Values of the pieces
Material advantage applies both strategically and tactically. Generally more pieces or an aggregate of more powerful pieces means greater chances of winning. A fundamental strategic and tactical rule is to capture opponent pieces while preserving one's own.
Bishops and knights are called minor pieces. A knight is about as valuable as a bishop, but less valuable than a rook. Rooks and the queen are called major pieces. Bishops are usually considered slightly better than knights in open positions, such as toward the end of the game when many of the pieces have been captured, whereas knights have an advantage in closed positions. Having two bishops is a particularly powerful weapon, especially if the opposing player lacks one or both of his bishops.
Three pawns are more likely to be useful than a knight in the endgame, but in the middlegame a knight is often more powerful. Two minor pieces are stronger than a single rook, and two rooks are slightly stronger than a queen.
One commonly used simple scoring system is:
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Piece Value Pawn 1 Bishop 3 Knight 3 Rook 5 Queen 9 King ∞
Under a system like this, giving up a knight or bishop in order to win a rook ("winning the exchange") is advantageous and is worth about two pawns. This of course ignores such complications as the current position and freedom of the pieces involved, but it is a good starting point. In an open position, bishops will be more valuable than knights (a bishop pair can easily be worth seven points or more in some situations); conversely, in a closed position, bishops will be less valuable than knights. Also, many pieces have a partner. By doubling up two knights, two rooks, rook and queen or bishop and queen the pieces can get stronger than the sum of the individual pieces alone. When pieces lose their partner, their values slightly decrease. The king is priceless since its loss causes the loss of the game. However, especially in the endgame, the king can also be a fighting piece, and is sometimes given a fighting value of four.
[edit] Space
All other things being equal, the side which controls more space on the board has an advantage. More space means more options, which can be exploited both tactically and strategically. If all of one's pieces are developed and no tactical tricks or promising long-term plan is apparent, he could try to find a move which will enlarge his influence, particularly in the centre. However, in some openings, one player will accept less space for a period of time to set up a counterattack in the middlegame. This is one of the concepts behind hypermodern play.
The easiest way to gain space is to push the pawn skeleton forward. However, one must be careful not to over stretch. If the opponent succeeds in getting a protected piece behind enemy lines, this piece can become such a serious problem that a piece with a higher value might have to be exchanged for it.
[edit] Defending pieces
It is important to defend one's pieces even if they are not directly threatened. This helps stop possible future campaigns from the opponent. If a defender must be added at a later time, this may cost a tempo or even be impossible due to a fork or discovered attack. The approach of always defending one's pieces has an antecedent in the theory of Aron Nimzowitsch who referred to it as "overprotection." Similarly, if one spots undefended enemy pieces, one should immediately take advantage of those pieces' weakness.
Even a defended piece can be vulnerable. If the defending piece is also defending something else, it is called an overworked piece, and may not be able to fulfill its task. When there is more than one attacking piece, the number of defenders must also be increased, and their values taken into account. Except for defending pieces, it is also often necessary to defend key squares, open files and the backrank. These situations can easily occur if the pawn structure is weak.
[edit] Exchanging pieces
To exchange pieces means to capture a hostile piece and then allow a piece of the same value to be captured. As a general rule of thumb, exchanging pieces eases the task of the defender who typically has less room to operate in.
Exchanging pieces is usually desirable to a player with an existing advantage in material, since it brings the endgame closer and thereby leaves the opponent with less time in which to recover ground. In the endgame even a single pawn advantage may decide the game.
When playing against stronger players, many beginners attempt to constantly exchange pieces "to simplify matters". However, stronger players are often relatively stronger in the endgame, whereas errors are more common during the more complicated middlegame.
Note that "the exchange" may also specifically mean a rook for a bishop or knight.
[edit] Specific pieces
[edit] Pawns
In the endgame, passed pawns, those which cannot be hindered by enemy pawns from promotion, are strong, especially if they are advanced or protected by another pawn. A passed pawn on the sixth row is roughly as strong as a knight or bishop and will often decide the game. (Also see isolated pawn, doubled pawns, backward pawn, connected pawns).
[edit] Knights
Since knights can easily be chased away with pawn moves, it is often advantageous for knights to be placed in "holes" in the enemy position (an outpost), squares where they cannot be attacked by a pawn. Such a knight on the fifth rank is a strong asset, and one on the sixth rank may exercise as much power as a rook. A knight at the edge or corner of the board controls fewer squares than one on the board's interior.
A king + knight is not sufficient material to mate an opposing lone king.
[edit] Bishops
A bishop always stays on squares of the color it started on, so once one of them is gone, the squares of the other color become more difficult to control. When this happens, pawns moved to squares of the other color do not block the bishop, and enemy pawns directly facing them are stuck on the vulnerable color.
A fianchettoed bishop at, e.g., g2 after pawn g2-g3, can provide a strong defence for the castled king on g1 and often exert pressure on the long diagonal h1-a8. After a fianchetto, giving up the bishop can weaken the holes in the pawn chain; doing so in front of the castled king may thus impact its safety.
In general, a bishop is of roughly equal value to a knight. In certain circumstances, one can be more powerful than the other. If the game is "closed" with lots of interlocked pawn formations, the knight tends to be stronger, because it can hop over the pawns while they block the bishop. A bishop is also weak if it is restricted by his own pawns, especially if they are blocked and on the bishop's colour. Once a bishop is lost, the remaining bishop is considered weaker since the opponent can now plan his moves to play a white or black colour game.
In an open game with action on both sides of the board, the bishop tends to be stronger because of its long range. This is especially true in the endgame; if passed pawns race on opposite sides of the board, the player with a bishop usually has better winning chances than a player with a knight.
A king + bishop is not sufficient material to mate an opposing lone king.
[edit] Rooks
Rooks have more scope of movement on Half-open files (ones which do not contain pawns of one's own colour). Rooks on the seventh rank can be very powerful as they attack pawns which can only be defended by other pieces, and they can restrict the enemy king to its back rank. A pair of rooks on the player's seventh rank is often a sign of a winning position.
In middlegames and endgames with a passed pawn, Tarrasch's rule states that rooks, both friend and foe of the pawn, are usually strongest behind the pawn rather than in front of it.
A king + rook is sufficient material to mate an opposing lone king; thus the rook's distinction as a major piece above the knight and bishop.
[edit] Queen
Queens are the most powerful pieces. They have great mobility and can make many threats at once. For these reasons, checkmate attacks involving the queen are easier to achieve than those without. It is generally wise to wait to develop the queen until after the knights and bishops have been developed to prevent the queen from being attacked by minor pieces and losing tempo.
[edit] King
During the middle game, the king is often best protected in a corner behind his pawns. If the rooks and queen leave the first rank however, an enemy rook can checkmate the king by invading the first rank. Moving one of the pawns in front of the king (making a luft) can allow it an escape square, but may weaken the king's position.
The king can become a strong piece in the endgame. With reduced material, a quick mate is not an immediate concern anymore, and moving the king towards the center of the board gives it more opportunities to make threats and actively influence play.
[edit] Considerations for a successful long term deployment
[edit] Strategy and tactics
Chess strategy consists of setting and achieving long-term goals during the game — for example, where to place different pieces — while tactics concentrate on immediate maneuver. These two parts of chess thinking cannot be completely separated, because strategic goals are mostly achieved by the means of tactics, while the tactical opportunities are based on the previous strategy of play.
Because of different strategic and tactical patterns, a game of chess is usually divided into three distinct phases: Opening, usually the first 10 to 25 moves, when players develop their armies and set up the stage for the coming battle; middlegame, the developed phase of the game; and endgame, when most of the pieces are gone and kings start to take an active part in the struggle.
[edit] Opening
A chess opening is the group of initial moves of a game (the "opening moves"). Recognized sequences of opening moves are referred to as openings and have been given names such as the Ruy Lopez or Sicilian Defence. They are catalogued in reference works such as the Encyclopaedia of Chess Openings. It is recommended for anyone but the chessmasters, that when left with a choice to either follow a standard opening or invent a new variation, one should do the first.
There are dozens of different openings, varying widely in character from quiet positional play (e.g. the Réti Opening) to very aggressive (e.g. the Latvian Gambit). In some opening lines, the exact sequence considered best for both sides has been worked out to 30–35 moves or more.[2] Professional players spend years studying openings, and continue doing so throughout their careers, as opening theory continues to evolve.
The fundamental strategic aims of most openings are similar:[3]
- Development: To place (develop) the pieces (particularly bishops and knights) on useful squares where they will have an impact on the game.
- Control of the center: Control of the central squares allows pieces to be moved to any part of the board relatively easily, and can also have a cramping effect on the opponent.
- King safety: Correct timing of castling can enhance this.
- Pawn structure: Players strive to avoid the creation of pawn weaknesses such as isolated, doubled or backward pawns, and pawn islands.
During the opening, some pieces have a recognised optimum square they try to reach. Hence, an optimum deployment could be to push the king and queen pawn two steps followed by moving the knights so they protect the centre pawns and give additional control of the centre. One can then deploy the bishops, protected by the knights, to pin the opponents knights and pawns. The optimum opening is ended with a castling, moving the king to safety and deploying for a strong back-rank and a rook along the centre file.
Apart from these fundamentals, other strategic plans or tactical sequences may be employed in the opening.
Most players and theoreticians consider that White, by virtue of the first move, begins the game with a small advantage. Black usually strives to neutralize White's advantage and achieve equality, or to develop dynamic counterplay in an unbalanced position.
[edit] Middlegame
The middlegame is the part of the game when most pieces have been developed. Because the opening theory has ended, players have to assess the position, to form plans based on the features of the positions, and at the same time to take into account the tactical possibilities in the position.[4]
Typical plans or strategic themes — for example the minority attack, that is the attack of queenside pawns against an opponent who has more pawns on the queenside — are often appropriate just for some pawn structures, resulting from a specific group of openings. The study of openings should therefore be connected with the preparation of plans typical for resulting middlegames.
Middlegame is also the phase in which most combinations occur. Middlegame combinations are often connected with the attack against the opponent's king; some typical patterns have their own names, for example the Boden's Mate or the Lasker—Bauer combination.
Another important strategical question in the middlegame is whether and how to reduce material and transform into an endgame (i.e. simplify). For example, minor material advantages can generally be transformed into victory only in an endgame, and therefore the stronger side must choose an appropriate way to achieve an ending. Not every reduction of material is good for this purpose; for example, if one side keeps a light-squared bishop and the opponent has a dark-squared one, the transformation into a bishops and pawns ending is usually advantageous for the weaker side only, because an endgame with bishops on opposite colors is likely to be a draw, even with an advantage of one or two pawns.
[edit] Endgame
The endgame (or end game or ending) is the stage of the game when there are few pieces left on the board. There are three main strategic differences between earlier stages of the game and endgame:[5]
- During the endgame, pawns become more important; endgames often revolve around attempting to promote a pawn by advancing it to the eighth rank.
- The king, which has to be protected in the middlegame owing to the threat of checkmate, becomes a strong piece in the endgame and it is often brought to the center of the board where it can protect its own pawns, attack the pawns of opposite color, and hinder movement of the opponent's king.
- Zugzwang, a disadvantage because the player has to make a move, is often a factor in endgames and rarely in other stages of the game. For example, in the diagram on the right, Black on move must go 1...Kb7 and allow white to queen after 2.Kd7, while White on move must allow a draw either after 1.Kc6 stalemate or losing the last pawn by going anywhere else.
Endgames can be classified according to the type of pieces that remain on board. Basic checkmates are positions in which one side has only a king and the other side has one or two pieces and can checkmate the opposing king, with the pieces working together with their king. For example, king and pawn endgames involve only kings and pawns on one or both sides and the task of the stronger side is to promote one of the pawns. Other more complicated endings are classified according to the pieces on board other than kings, e.g. "rook and pawn versus rook endgame".
[edit] Quotes
- "Strategy requires thought; tactics requires observation." - Max Euwe
- "When you see a good move wait - look for a better one." - Emanuel Lasker
[edit] See also
Wikibooks has a book on the topic of |
[edit] References
- ^ "Tarrasch vs Euwe on chessgames.com". http://www.chessgames.com/perl/chessgame?gid=1006866. (Java needed)
- ^ Collins, Sam (2005). Understanding the Chess Openings. Gambit Publications. ISBN 1-904600-28-X.
- ^ Tarrasch, Siegbert (1987). The Game of Chess. Courier Dover Publications. ISBN 0-486-25447-X.
- ^ Harding (2003), p. 32–151
- ^ Harding (2003), p. 187ff
- Josh Waitzkin (2002). Chessmaster 8000 Classroom
[edit] Further reading
- John Nunn (2001). Understanding Chess Move by Move. Gambit. An International Grandmaster explains the thinking behind every single move of many world-class games.
- Jeremy Silman (1999). The Amateur's Mind: Turning Chess Misconceptions into Chess Mastery. Siles Press. A chess teacher analyzes and corrects the thinking of advanced beginners.
- James Eade (2001). Chess for Dummies. Gambit. A comprehensive guide for beginners.
- Yasser Seirawan (2005). Winning Chess Strategies. Everyman Chess. ISBN 1-85744-385-3.
[edit] External links
- 64 Commandments of Chess by Bruce Pandolfini
- Chess Strategy, Second Edition (also at Gutenberg-project), and Chess and Checkers: the Way to Mastership by Edward Lasker
- The Blue Book of Chess; "Teaching the Rudiments of the Game, and Giving an Analysis of All the Recognized Openings" by Howard Staunton
- Chess Strategy, free lessons on basic elements.
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