Chess strategy and tactics

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Chess strategy and tactics have evolved through the centuries as the most successful players have added to the body of knowledge. It has been learned that for a player to maximize his winning chances, he must rapidly mobilize all of his chess pieces and provide them with significant manuvering room, while simultaneously preventing his opponent from doing the same. This so-called "positional" approach to chess is the basis for modern chess strategy. Of course, good positioning of pieces only creates opportunities for victory. In order to close the game and win, a player must make accurate calculations of sequences of moves (variations) that lead either to outright victory, or to a significant advantage, all the while preventing such sequences from being played by the opponent.

In contrast to the positional concepts that underlie chess strategy, chess tactics enable a player to leverage the way the pieces move, along with the geometry of the chessboard, to immediately accomplish various useful objectives, often against the will of their opponent. These objectives include such things as bolstering or thwarting attacks on the kings, eliminating a larger portion of the opponent's fighting force than one's own, or otherwise posing undesired difficulties for the opponent.

It has been considered by Chess masters that increasing the positional advantages leads to a greater number of favorable tactical possibilities.

"Strategy requires thought; tactics requires observation." - Max Euwe

In describing tactics and strategy, we will use the algebraic chess notation.

Contents

Values of the pieces

Main article: Chess piece point value

One thing that applies both strategically and tactically is material advantage. If you command more pieces, or more powerful pieces, than your opponent, you will have greater opportunity. Beginners are therefore advised to always consider capturing their opponent's pieces and saving their own. The capturing piece lands on a square where, often, it can be recaptured, so you need to know which piece is more valuable.

A knight is about as valuable as a bishop (these two are called minor pieces), but less valuable than a rook, and less still than a queen (rooks and queens are called major pieces). Bishops are usually considered to be 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 has lost one or both of his bishops.

Three pawns are likely to be more 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. Two rooks are stronger than a queen, but not by much.

One commonly used simple scoring system is 1 point for a pawn, 3 for a knight or bishop, 5 for a rook, and 9 for a queen. 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 7 points or more in some situations); conversely, in a closed position, bishops will be less valuable than knights. The king is infinitely valuable since its loss causes the loss of the game.

Tactics

Attacking and defending pieces

A piece is said to attack an opponent's piece if, in the next move, it could capture that piece. A piece is said to defend or to protect a piece of the defender's color if, in case the defended piece were taken by the opponent, the defender could recapture right away. Attacking a piece forces the opponent to respond only if the attacked piece is undefended, or if the attacking piece is of lower value than the attacked one.

Forks

Main article: fork

A fork is a move that uses one piece to attack two of the opponent's pieces at the same time, hoping to achieve material advantage (because the opponent can only counter one of the two threats). Knights are often used for forks: they jump to a position from where they attack two pieces. A quite common situation is a white knight jumping to c7, thereby threatening both the rook at a8 and the king at e8. Such "king forks" are particularly effective, because the opponent is forced by the rules of the game to counter the threat to the king; the opponent cannot choose to defend the other piece, and thus cannot use a zwischenzug (see below) to complicate the situation. Pawns can also fork enemy pieces: by moving a pawn forward, it may attack two pieces: one diagonally to the left and one diagonally to the right. A common situation is the move Pawn d2-d4 forking a black bishop at c5 and a black knight at e5.

Kasparov vs. World Team 1999
Kasparov played 12.Nc7+ A variation of the Three Knights Opening
1.e4 e5 2.Nf3 Nc6 3.Nc3 Bc5 4.Nxe5 Nxe5 5.d4

A queen move also often attacks two pieces at the same time, but this is only useful if both pieces are undefended, or if one is undefended and the other is the opposing king. The queen is more valuable than the pieces it is attacking, so it is usually not profitable for it to capture a defended piece.

Pins

Main article: pin

"The defensive power of a pinned piece is only imaginary." - Aron Nimzowitsch

A pin is a move which forces one of the opponent's pieces to stay put because moving it would expose a more valuable piece behind it. As they move in a straight line, bishops, rooks, and queens can pin other pieces.

In the left diagram, black can't move the knight without losing the queen, and Black's rook can't be moved at all. In the right diagram, Kramnik pins black's bishop and soon wins it with a4-a5.

Morphy vs. Consultation Team 1858
after Morphy's 14th move Vladimir Kramnik vs. Alexander Morozevich 2002 Rapid Play
Kramnik played 31.Rb1

Skewers

''Main article: skewer

A skewer is a move which attacks two pieces in a line, similar to a pin, except that the enemy piece of greater value is in front of the enemy piece of lesser value. After the more valuable piece moves away, the lesser piece can be captured. Queens, rooks, and bishops can skewer.

Lasker vs. Bauer 1889
Lasker played 33.Qg7+ Tal vs. Botvinnik 1960
Tal played 30.Bc4

Because of possible pins and skewers, one should be extremely cautious if king and queen are located on the same vertical, horizontal or diagonal line, or can be forced into such an arrangement.

Discovered attacks

Main article: discovered attack

A discovered attack is a move which unmasks an attack by another piece. A piece is moved away so as to unmask the attack of a friendly bishop, rook or queen on an enemy piece. If the attacked piece is the king, we speak of a discovered check. Discovered attacks are powerful, because if the moving piece manages to pose a second threat, the opponent is in trouble.

Torre vs. Lasker 1925
Torre played 31.Rg5+ Byrne vs. Fischer 1956
Fischer played 22...Nc3+

A special case of a discovered check is a double check, where both the piece being unmasked and the piece being moved attack the enemy king. A double check requires that your opponent move his/her king as the king is under attack from two directions and it is impossible to counter both at the same time in any other way.

Zwischenzug

Main article: zwischenzug

The German zwischenzug means "intermediate move"; it is a common tactic that occurs in almost every game: instead of countering a direct threat, which the opponent expects, a move is played which poses an even more devastating threat, often an attack against the queen or the king. The opponent has to counter that threat first, and this will ideally change the situation to a disadvantage.

When you plan your tactics, you should always watch out for a zwischenzug. Don't assume that the opponent has to counter your threats immediately. It is good practice to always check whether your opponent has a check or a move threatening your queen. Conversely, anticipate your opponent's threats and plan a surprising zwischenzug.

Sacrifices

Main articles: gambit, exchange sacrifice

Often it is necessary to throw the opponent's position or tempo out of balance by first sacrificing some material, sometimes to be regained with interest a couple of moves later. Pawn sacrifices in the opening are known as gambits; they are usually not intended for material short-term gain but instead to achieve a more active position.

Direct attacks against the enemy king are often started by sacrifices; a common example is a bishop sacrificing itself on h7, checking the king on g8 who has to take the bishop, after which the white queen and knight develop a fulminant attack.

Attacks against the king

Colle vs. O'Hanlon, 1930
Colle played 12.Bxh7+

Attacks against the castled king are usually justified by some imbalance: you have more firepower on the king's side than your opponent, or the opponent weakened his king's position by moving one of the pawns in front of the king.

Many mating attacks are introduced by sacrifices: if mate is the goal, material doesn't matter anymore. The queen is almost always the most important piece in a mating attack, since she has various ways of mating a king. The most common is a direct "contact check" while being protected by one of her own pieces. For instance, white knight g5, black king on g8 and the queen mates at h7, or black bishop at f6 or h6 and the white queen on g7 mates the black king on g8.

Don't assume that every move in a mating attack has to be a check. Often, a check just drives the king to a better position, or weakens your own setup. Try to find "quiet" moves which seal the deal.

Zugzwang

Main article: zugzwang

In chess, zugzwang (German for "compulsion to move") occurs when one player, because it is his turn to move, must make a move but every possible move weakens his position. The player is put at a disadvantage because he would like to pass and make no move, but a move has to be made. Situations involving zugzwang occur uncommonly; when they do occur, it is most commonly in the endgame, where there are fewer choices of available moves.

Strategy

Opening

Main article: chess opening

For beginners, it is not helpful to memorize opening moves. Instead, by carefully following a handful of principles, one can typically achieve a decent position for the middle game unless facing an exceptionally skilled opponent.

The most important part of the board is the center (e4, d4, e5, d5). The first goal is to position pawns and minor pieces in such a way as to control the center. The second goal is to move the king away from the dangerous center by castling. The third goal is to mobilize (develop) as many major pieces as possible.

Every move should contribute to these goals and one should avoid losing time by making useless moves. The white knights are usually developed to c3 and f3 upon their first moves. The queen should avoid moving too early and too far into enemy territory because otherwise the opponent will be able to play developing moves which at the same time threaten the queen. Once castling has been achieved, the remaining bishops and knights should be moved out of the way so that the two rooks protect each other and operate more effectively. This usually requires the first 10 moves or more and ends the opening phase of the game.

Space

All other things being equal, the side which controls more space on the board has an advantage. More space translates into more options, which can be exploited both tactically and strategically. So if all your pieces are developed and you don't see any tactical tricks or a promising long-term plan, try to find a move which will enlarge your influence, particularly in the center. However, in some openings, one player will accept less space for a period of time in order to set up a counterattack in the middlegame. This is one of the concepts behind hypermodern play.

Defending pieces

In general, it is a good idea to defend your pieces, even if they are not currently attacked. This way, many tactical tricks of the opponent won't work. In fact, this approach has an antecedent in the theory of Aron Nimzowitch who referred to it as "overprotection." Conversely, if you spot undefended pieces of the opponent, you should think about exploiting the situation with a tactical combination.

Exchanging pieces

Main articles: minor exchange, exchange sacrifice

To exchange pieces means to capture a hostile piece and then allow a piece of the same value to be captured. Often it's the same type of piece that was captured that is subsequently captured by the opponent. As a general rule of thumb, exchanging pieces eases the task of the defender who typically has less room to operate in.

If you have a material advantage, exchanging pieces is usually desirable, since 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"; this is a poor strategy. Stronger players are normally relatively stronger in the endgame, whereas during a complicated middlegame, even they can make mistakes.

(Note that "winning the exchange" has a special meaning as mentioned above: winning a rook for a bishop or knight.)

Specific pieces

Pawns

Main article: pawn structure

In the endgame, passed pawns, those which cannot be hindered by enemy pawns from promotion, are strong, especially if they are advanced. 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).

Knights

Main article: knight

Knights are easily chased away with pawn moves. Therefore it is important to spot "holes" in the enemy position where a knight cannot be attacked, because the pawns have already moved past. Once such a hole is identified, a knight should be maneuvered to that location. An unchallengeable knight on the fifth row is a strong asset, and a supported knight on the sixth row usually decides the game. Unless there is a good reason for it, knights shouldn't be placed at the borders (and never in the corners) of the board, because there they control far fewer squares and can often be captured.

Bishops

Main articles: bishop, fianchetto

A bishop always stays on squares of the colour it started on. This is not a big concern if you still have both bishops, but once one of them is gone, you should keep in mind that you now have a hard time attacking or defending squares of the other colour. If you have only one bishop left, you typically want to move your pawns to squares of the other colour so that they don't block the bishop and so that the enemy pawns are stuck on the right colour and can be attacked.

If you don't see a good square for development of a bishop, you can consider a fianchetto: pawn g2-g3 and bishop f1-g2. This forms a strong defense for the castled king on g1 and the bishop can often exert pressure on the long diagonal h1-a8. After a fianchetto, you should not give up the bishop too easily, because then the holes around the king can easily prove fatal.

To decide whether in a given position a knight or a bishop is more powerful, several aspects have to be taken into account: if the game is "closed" with lots of interlocked pawn formations, the knight will be stronger, because it can hop over the pawns while the bishop is blocked by them. A bishop is also weak if it is permanently blocked by his own pawns, which are arrested on the wrong colour. In an open game with action on both sides of the board, the bishop will 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 bishop will usually win over the knight here.

An endgame in which the parties have bishops that live on different colours is almost always drawn, even if one side is two pawns ahead.

Rooks

Main article: rook

Rooks are powerful on half-open files -- files which don't contain pawns of your own colour. Rooks on the seventh rank can be very powerful as they attack pawns which can only be defended by other pieces, not by other pawns, and they can lock in the enemy king. A pair of white rooks on the seventh rank (or black on the second rank) is often a sign of a winning position.

In the endgame, if there is a passed pawn which is a candidate for promotion, the rooks, both friend and foe of the pawn, generally belong behind the pawn rather than in front of it, see Tarrasch rule.

Queen

Main article: queen

Queens are the most powerful pieces in a chess game. Queens are extremely versatile, and can threaten many pieces at once. For this reason, checkmates involving the queen are much easier to achieve than those without her. Because the loss of a queen usually results in the loss of the game, it is generally wise to wait to develop a queen until after the knights and bishops have been developed. It is important, however, to remember that the loss of a queen does not always result in the loss of the game.

King

Main article: king

During the middle game, the king mostly stays in a corner behind his pawns. Moving these pawns should be avoided because that weakens the king's position. However, as the rooks leave the first row, there is a danger of an enemy rook invading the first row and mating the king, so sometimes it is necessary to move one of the pawns in front of the king to counter these mate threats.

In the endgame, the king becomes a strong piece. With reduced material, mate is not an immediate concern anymore, and the king should be moved towards the center of the board.

Endgame

Main article: endgame

Once most pieces have been exchanged off the board, it becomes impossible to mount direct attacks on the king. In this situation, the focus of the game switches to attempting to bring a pawn to the eighth rank and promote it, usually to a queen, while preventing one's opponent from doing so. The promoted queen, provided it is not immediately captured by the opponent, is enough to ensure a win.

If only one pawn is left (and maybe one other piece on either side), then both players should attempt to direct their kings in front of the pawn in order to gain influence, keep the other king away and ensure (or prevent) the pawn's promotion. See the article on king and pawn versus king endgames for more discussion on this topic.

In endgames that involve only kings and pawns, the concept of opposition (See for opposition) is important: by moving to a square which is horizontally, vertically or diagonally two squares away from the enemy king, one "gains" the opposition. This is an advantage, because it forces the enemy king to give way.

Moving his king to d5, white gains the opposition and
wins the game. All other moves result in white losing the opposition and black can save the game by controlling and keeping this opposition.

Sometimes, all pawns will be eliminated from the board and one player will be left with a king and some combinations of rooks, knights and bishops against a lone king. These give rise to the elementary checkmates:

King and queen vs. king
King and rook vs. king
King and two bishops vs. king
King, bishop and knight vs. king

The first two are relatively easy to learn and commonly arise in beginner games. See for a demonstration of these two checkmates. Many beginners, notably children, fail to win games simply because they have never learned these procedures. The other two require more skill, but arise much less frequently. A king and one minor piece is never enough to win and thus the game will be a draw. A king with two knights against a king is insufficient to force a win; however, since this inability is partly a result of poor timing inherent in the knight's awkward moves there are circumstances where a win can be forced if the opponent also has a pawn. Although a king and three knights versus king is also sufficient for a win, such a situation rarely occurs because, for such a position to arise, a pawn must have been promoted to become the third knight whereas most players would usually choose to promote the pawn to become a queen to quickly end the game.

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
[Thousands of Chess Puzzles by Grandmasters]
[Tactics technical papers suite]
[The Blue Book of Chess]; "Teaching the Rudiments of the Game, and Giving an Analysis of All the Recognized Openings" by Howard Staunton

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