The endgame (or ending) is the final stage of a chess game which occurs after the middlegame. It begins when few pieces are left on the board.
The line between the middlegame and the endgame is often not clear, and may occur gradually or with a quick exchange of pieces. The endgame, however, tends to have different characteristics from the middlegame, and the players have correspondingly different strategic concerns. In particular, pawns become more important as endgames often revolve around attempts to promote a pawn by advancing it to the eighth . The king, which normally is kept safe during the game, becomes active in the endgame, as it can help escort pawns to promotion, attack enemy pawns, protect other pieces, and restrict the movement of the enemy king. Not all chess games reach an endgame; some of them end earlier.
All chess positions with up to seven pieces on the board have been solved by endgame tablebases, so the outcome (win, loss, or draw) of best play by both sides in such positions is known, and endgame textbooks teach this best play. However, most endgames are not solved, and even those which are can be difficult for humans to play, so textbooks teach useful strategies and tactics about them. The body of chess theory devoted to endgames is known as endgame theory. Compared to opening theory, which changes frequently, giving way to middlegame positions that fall in and out of popularity, endgame theory is less subject to change.
Many endgame studies have been composed; they consist of endgame positions which are solved by finding a win for White when there is no obvious way to win, or finding a draw when White appears to lose. In some compositions, the starting position would be unlikely to occur in an actual game; but if the starting position is not artificial, the composition may be incorporated into endgame theory.
Endgames are usually classified based on the type of pieces that remain.
The start of the endgame There is no strict criterion for when an endgame begins, and different authors have different opinions. The former World Chess Champion Alexander Alekhine said, "We cannot define when the middle game ends and the endgame starts." Using the standard system for chess piece relative value, Speelman considers that endgames are positions in which each player has thirteen or fewer points in (not counting the king). Alternatively, they are positions in which the king can be used actively, but there are some famous exceptions to that. Minev characterizes endgames as positions having four or fewer pieces other than kings and pawns. Fine considers endgames to be positions without queens. Flear considers endgames to be positions where both players have at most one piece (other than kings and pawns) whereas Dvoretsky considers them to be positions in which at least one player has such a material configuration. Some problem composers believe that the endgame starts when the player to move can force a win or a draw against any variation of moves.
Alburt and Krogius give three characteristics of an endgame:
Endgames favor an aggressive king. Passed pawns increase greatly in importance. Zugzwang is often a factor in endgames and rarely in other stages of the game.
Mednis and Crouch address the question of what constitutes an endgame negatively. They believe that the game is in the endgame if these apply: better ; open for attacking; vulnerable king position; misplaced pieces.
General considerations Generally, the player having a material advantage tries to exchange pieces but avoids exchanging pawns in the endgame. Some exceptions to this are:
Endings in which both sides have two rooks and some pawns – the player with more pawns should not exchange a pair of rooks Endings in which both sides have bishops on opposite colors with other pieces – the stronger side should avoid exchanging the other pieces Endings in which all the pawns are on the same side of the board – the stronger side should try to create a passed pawn by exchanging pawns
Usually, endings with pawns on both sides of the board are easier to win and the first player to promote a pawn to a queen wins if the opponent is unable to do so on the turn immediately after.
Max Euwe and Walter Meiden give these five generalizations: In king and pawn endings, an extra pawn is decisive in more than 90 percent of the cases. In endgames with pieces and pawns, an extra pawn is a winning advantage in 50 to 60 percent of the cases. It becomes more decisive if the stronger side has a positional advantage. The king plays an important role in the endgame. Initiative is more important in the endgame than in other phases of the game. In rook endgames, the initiative is usually worth at least a pawn. Two connected passed pawns are very strong. If they reach their sixth rank, they are as powerful as a rook.
Common types of endgames
Endings with no pawns Basic checkmates
Many endings without pawns have been solved, that is, best play for both sides from any starting position can be determined, and the outcome (win, loss, or draw) is known. For example, the following are all wins for the side with pieces: king and queen against a king—A queen, with its king, can easily checkmate a lone king. king and rook against a king king and two bishops of opposite color against a king king, bishop, and knight against a king
See Wikibooks – Chess/The Endgame for a demonstration of the first two checkmates, which are generally taught in textbooks as basic knowledge. The last two are sometimes taught as basic knowledge as well, although the procedure for mate with bishop and knight is relatively difficult and many tournament players do not know it.
Other endings with no pawns
The ending of king and bishop versus king is a trivial draw, in that checkmate is not even possible. Likewise for king and knight versus king.
Two knights cannot force checkmate against a lone king (see Two knights endgame). While there is a board position that allows two knights to checkmate a lone king, such requires a careless move by the weaker side to execute. If the weaker side also has material (besides the king), checkmate is sometimes possible. The winning chances with two knights are insignificant except against a few pawns. () The procedure can be long and difficult. In competition, the fifty-move rule will often result in the game being drawn first.
The endgame of king and three knights against king will not normally occur in a game, but it is of theoretical interest. The three knights win.
Two of the most common pawnless endgames (when the defense has a piece in addition to the king) are (1) a queen versus a rook and (2) a rook and bishop versus a rook. A queen wins against a rook — see Queen versus rook endgame. A rook and bishop versus a rook is generally a theoretical draw, but the defense is difficult and there are winning positions (see Rook and bishop versus rook endgame).
King and pawn endings King and pawn endgames involve only kings and pawns on one or both sides. International Master Cecil Purdy said, "Pawn endings are to chess as putting is to golf." Any endgame with pieces and pawns has the possibility of into a pawn ending.
In king and pawn endings, an extra pawn is decisive in more than 90 percent of the cases. Getting a passed pawn is crucial (a passed pawn is one which does not have an opposing pawn on its file or on adjacent files on its way to promotion). Nimzowitch once said that a passed pawn has a "lust to expand". An is particularly deadly. The point of this is a deflection – while the defending king is preventing the outside passed pawn from queening, the attacking king wins pawns on the other side.
Opposition is an important technique that is used to gain an advantage. When two kings are in opposition, they are on the same (or ) with one empty square separating them. The player having the move loses the opposition. That player must move the king and allow the opponent's king to advance. However, the opposition is a means to an end, which is penetration into the enemy position. The attacker should try to penetrate with or without the opposition. The tactics of triangulation and zugzwang as well as the theory of corresponding squares are often decisive.
Unlike most positions, king and pawn endgames can usually be analyzed to a definite conclusion, given enough skill and time. An error in a king and pawn endgame almost always turns a win into a draw or a draw into a loss – there is little chance for recovery. Accuracy is most important in these endgames. There are three fundamental ideas in these endgames: opposition, triangulation, and the Réti manoeuvre.
King and pawn versus king
This is one of the most basic endgames. A draw results if the defending king can reach the square in front of the pawn or the square in front of that (or capture the pawn). If the attacking king can prevent that, the king will assist the pawn in being promoted to a queen or rook, and checkmate can be achieved. A is an exception because the king may not be able to get out of the way of its pawn.
Knight and pawn endings Knight and pawn endgames feature clever manoeuvring by the knights to capture opponent pawns. While a knight is poor at chasing a passed pawn, it is the ideal piece to block a passed pawn. Knights cannot lose a tempo, so knight and pawn endgames have much in common with king and pawn endgames. As a result, Mikhail Botvinnik stated, “A knight ending is really a pawn ending.”
Knight and pawn versus knight
This is generally a draw since the knight can be sacrificed for the pawn, however, the king and knight must be covering squares in the pawn's path. If the pawn reaches the seventh rank and is supported by its king and knight, it usually promotes and wins. In this position, White to move wins: 1. b6 Nb7! 2. Ne6! Na5 3. Kc8! N-any 4. Nc7#. If Black plays the knight to any other square on move 2, White plays Kc8 anyway, threatening b7+ and promotion if the knight leaves the defense of the b7 square. Black to move draws starting with 1... Nc4 because White cannot gain a tempo.
Bishop and pawn endings
Bishop and pawn endgames come in two distinctly different variants. If the opposing bishops go on the same color of square, the mobility of the bishops is a crucial factor. A is one that is hemmed in by pawns of its own color, and has the burden of defending them.
The adjacent diagram, from Molnar–Nagy, Hungary 1966, illustrates the concepts of good bishop versus bad bishop, opposition, zugzwang, and outside passed pawn. White wins with 1. e6! (vacating e5 for his king) 1... Bxe6 2. Bc2! (threatening Bxg6) 2... Bf7 3. Be4! (threatening Bxc6) 3... Be8 4. Ke5! (seizing the opposition [i.e. the kings are two orthogonal squares apart, with the other player on move] and placing Black in zugzwang—he must either move his king, allowing White's king to penetrate, or his bishop, allowing a decisive incursion by White's bishop) 4... Bd7 5. Bxg6!
Bishop and pawn versus bishop on the same color
Two rules given by Luigi Centurini in the 19th century apply: The game is a draw if the defending king can reach any square in front of the pawn that is opposite in color to the squares the bishops travel on. If the defending king is behind the pawn and the attacking king is near the pawn, the defender can draw only if his king is attacking the pawn, he has the opposition, and his bishop can move on two diagonals that each have at least two squares available (other than the square it is on). This is the case for and the whose promotion square is not the same color as the bishop.
The position in the second diagram shows a winning position for White, although it requires accurate play. A always wins if the defending bishop only has one long diagonal available.