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A pawnless chess endgame is a chess endgame in which only a few pieces remain and none of them is a pawn. The basic checkmates are types of pawnless endgames. Endgames without pawns do not occur very often in practice except for the basic checkmates of king and queen versus king, king and rook versus king, and queen versus rook (Hooper 1970:4). Other cases that occur occasionally are (1) a rook and minor piece versus a rook and (2) a rook versus a minor piece, especially if the minor piece is a bishop (Nunn 2007:156-65). The study of some pawnless endgames goes back centuries by players such as François-André Danican Philidor (1726-1795) and Domenico Lorenzo Ponziani (1719-1796). On the other hand, many of the details and recent results are due to the construction of endgame tablebases. Grandmaster John Nunn wrote a book (Secrets of Pawnless Endings) summarizing the research of endgame tablebases for several types of pawnless endings. The assessment of endgame positions assumes optimal play by both sides. In some cases, one side of these endgames can force a win; in other cases, the game is a draw (i.e. a book draw).
[edit] Terminology
[edit] Basic checkmatesMain article: checkmate Checkmate can be forced against a lone king with a king plus (1) a queen, (2) a rook, (3) two bishops, or (4) a bishop and a knight (see Bishop and knight checkmate). See checkmate for more details. [edit] Queen versus rook
Black is employing the third rank defense. White wins with correct play. A queen wins against a lone rook, unless there is an immediate draw by stalemate or due to perpetual check. Normally the winning process involves the queen first winning the rook by a fork and then checkmating with the king and queen, but forced checkmates with the rook still on the board are possible in some positions or against incorrect defense. The "third rank defense" by the rook is difficult for a human to crack. The "third rank defense" is when the rook is on the third rank or file from the edge of the board, his king is closer to the edge and the enemy king is on the other side (see the diagram). For example, the winning move in the position shown is the counterintuitive withdrawal of the queen from the seventh rank to a more central location, 1. Qf4, so the queen can make checking maneuvers to win the rook with a fork if it moves along the third rank. If the black king emerges from the back rank, 1... Kd7, then 2. Qa4+ Kc7; 3. Qa7+ forces Black into a second-rank defense (defending king on an edge of the board and the rook on the adjacent rank or file) after 3... Rb7. This position is a standard win, with White heading for the Philidor position with a queen versus rook (Müller & Lamprecht 2001:331-33). In 1895 Edward Freeborough edited an entire 130-page book of analysis of this endgame, The Chess Ending, King & Queen against King & Rook. [edit] Example from gameGelfand-Svidler, 2001
Black to move should win In this 2001 game[1] between Boris Gelfand and Peter Svidler,[2] Black should win but the game was a draw because of the fifty-move rule. Black can win in several ways, for instance:
The same position but with colors reversed occurred in a 2006 game between Alexander Morozevich and Dmitry Jakovenko – it was also drawn (Makarov 2007:170).[3] At the end of that game the rook became a desperado and the game ended in stalemate after the rook was captured. [edit] Queen versus two minor piecesPonziani 1782
Artificial position where the attacking king is confined, draw. Defensive fortresses exist for any of the two minor pieces versus the queen. However, except in the case of two knights, the fortress cannot usually be reached against perfect play. (See fortress for more details about these endings.)
[edit] Common pawnless endings (rook and minor pieces)John Nunn lists these types of pawnless endgames as being common: (1) a rook versus a minor piece and (2) a rook and a minor piece versus a rook (Nunn 2007:156-65).
Topalov-J. Polgar, 2008[5]
White to move, draw Philidor, 1749
White to move wins, Black to move draws (Nunn 2002:178) J. Polgar-Kasparov, 1996[7]
Position before White's 70th move, a draw with correct play. Polgar blundered on move 79 and resigned after move 90. Alekhine-Capablanca, 1927[8]
White to move, the game was drawn twelve moves later. The white king cannot be driven to the edge. Karpov-Ftáčnik, 1988[9]
Black to move. This combination is usually a draw but here White wins because the black king and knight are far apart (Müller & Pajeken 2008:237), (Karolyi & Aplin 2007:320-22), (Nunn 2007:158-59). [edit] Miscellaneous pawnless endingsOther types of pawnless endings have been studied (Nunn 2002). Of course, there are positions that are exceptions to these general rules stated below. The fifty-move rule is not taken into account, and it would often be applicable in practice. When one side has two bishops, they are assumed to be on opposite colored squares, unless otherwise stated. When each side has one bishop, the result often depends on whether or not the bishops are on the same color, so their colors will always be stated. [edit] Queens onlyComte vs. Le Roy, France, 1997
Whoever moves first wins (Nunn)
[edit] Major pieces onlyCenturini 1885 (Fine & Benko diagram 1096)
Black to move draws. Black would win with the king on h7 instead.
[edit] Queens and rooks with minor pieces
White to move wins in 85 moves, discovered by computer analysis
[edit] Queens and minor pieces
[edit] Examples from gamesNyazova-Levant, USSR 1976
White to move wins with 1. Qg8+ or 1. Qe6+ An endgame with queen and knight versus queen is usually drawn, but there are some exceptions where one side can quickly win material. In the game between Nyazova and Levant, White won:
White could have won more quickly by 1. Qg8+ Kh4 2. Qg3+ Kxh5 3. Qg6+ Kh4 4. Qh6+ and White skewers the black queen (Speelman 1981:108). Spassky-Karpov, 1982[12]
Position after 68. Nxb3, drawn on move 84 The second position is from a 1982 game between former world champion Boris Spassky and world champion Anatoly Karpov.[13]The game was drawn sixteen moves later. [edit] Rooks and minor piecesHorwitz and Kling, 1851
White to move wins
Karpov-Kasparov, 1991[14]
Position after 63. Kxh4. The game was drawn on move 115.
[edit] Minor pieces onlyECE #1907, Belle
1. Ba4+ wins in 66 moves (the only winning move), (Matanović 1993:512-13)
[edit] Example from gameBotvinnik-Tal, 1961[15]
Position after 77. Kxa6, Black wins An ending with two bishops versus a knight occurred in the seventeenth game of the 1961 World Chess Championship match between Mikhail Botvinnik and Mikhail Tal. The position occurred after White captured a pawn on a6 on his 77th move, and White resigned on move 84. [16]
White to move may draw in this position: 1. Nb7+ Kd5 2. Kc7 Bd2 3. Kb6 Bf4 4. Nd8 Be3+ 5. Kc7 (Hooper 1970:5). White gets his knight to b7 with his king next to it to form a long-term fortress.[17]
The game might continue 84. Kd7 Kb6 85. Nb3 Be3, followed by ...Bd1 and ...Bd4 (Speelman 1981:109-10), for example 86. Kd6 Bd1 87. Na1 Bd4 88. Kd5 Bxa1 (Hooper 1970:5). [edit] Fine's ruleIn his landmark 1941 book Basic Chess Endings, Reuben Fine inaccurately stated, "Without pawns one must be at least a Rook ahead in order to be able to mate. The only exceptions to this that hold in all cases are that the double exchange wins and that a Queen cannot successfully defend against four minor pieces." (Fine 1941:572) This inaccurate statement was repeated in the 2003 edition revised by Grandmaster Pal Benko (Fine & Benko 2003:585). However, Fine recognized elsewhere in his book that a queen wins against a rook (Fine 1941:561) and that a queen normally beats a knight and a bishop (with the exception of one drawing fortress) (Fine 1941:570-71). The advantage of a rook corresponds to a five-point material advantage using the traditional relative value of the pieces (pawn=1, knight=3, bishop=3, rook=5, queen=9). It turns out that there are several more exceptions, but they are endgames that rarely occur in actual games. Fine's statement has been superseded by computer analysis (Howell 1997:136). A four-point material advantage is often enough to win in some endings without pawns. For example, a queen wins versus a rook (as mentioned above, but 31 moves may be required); as well as when there is matching additional material on both sides, i.e.: a queen and any minor piece versus a rook and any minor piece; a queen and a rook versus two rooks; and two queens versus a queen and a rook. Another type of win with a four-point material advantage is the double exchange – two rooks versus any two minor pieces. There are some other endgames with four-point material differences that are generally long theoretical wins. In practice, the fifty-move rule comes into play because more than fifty moves are often required to either checkmate or reduce the endgame to a simpler case: two bishops and a knight versus a rook (requires up to 68 moves); and two rooks and a minor piece versus a queen (requires up to 82 moves for the bishop, 101 moves for the knight). A three-point material advantage can also result in a forced win, in some cases. For instance, some of the cases of a queen versus two minor piece are such positions (as mentioned above). In addition, the four minor pieces win against a queen. Two bishops win against a knight, but it takes up to 66 moves if a bishop is initially trapped in a corner (Nunn 1995:265ff). There are some long general theoretical wins with only a two- or three-point material advantage but the fifty-move rule usually comes into play because of the number of moves required: two bishops versus a knight (66 moves); a queen and bishop versus two rooks (two-point material advantage, can require 84 moves); a rook and bishop versus a bishop on the opposite color and a knight (a two-point material advantage, requires up to 98 moves); and a rook and bishop versus two knights (two-point material advantage, but it requires up to 222 moves) (Müller & Lamprecht 2001:400-6) (Nunn 2002:325-29). Finally, there are some other unusual exceptions to Fine's rule involving underpromotions. Some of these are (1) a queen wins against three bishops of the same color (no difference in material points), up to 51 moves are required; (2) a rook and knight win against two bishops on the same color (two point difference), up to 140 moves are needed; and (3) three bishops (two on the same color) win against a rook (four point difference), requiring up to 69 moves, and (4) four knights win against a queen (85 moves). This was proved by computer in 2005 and was the first ending with seven pieces that was completely solved. (See endgame tablebase.) [edit] General remarks on these endingsMany of these endings are listed as a win in a certain number of moves. That assumes perfect play by both sides, which is rarely achieved if the number of moves is large. Also, finding the right moves may be exceedingly difficult for one or both sides. When a forced win is more than fifty moves long, some positions can be won within the fifty move limit (for a draw claim) and others cannot. Also, generally all of the combinations of pieces that are usually a theoretical draw have some non-trivial positions that are a win for one side. Similarly, combinations that are generally a win for one side often have non-trivial positions which result in draws. [edit] TablesThis a table listing several pawnless endings, the number of moves in the longest win, and the winning percentage for the first player. The winning percentage can be misleading – it is the percentage of wins out of all possible positions, even if a piece can immediately be captured or won by a skewer, pin, or fork. The largest number of moves to a win is the number of moves until either checkmate or transformation to a simpler position due to winning a piece. Also, the fifty-move rule is not taken into account (Speelman, Tisdall & Wade 1993:7-8).
This table shows six-piece endgames with some positions requiring more than 100 moves to win (Stiller 1996).
[edit] See also[edit] Notes
[edit] References
[edit] Further reading
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