The rook and bishop versus rook endgame is a chess endgame where one player has just a king, a rook, and a bishop, and the other player has just a king and a rook. This combination of material is one of the most common pawnless chess endgames. It is generally a theoretical draw, but the rook and bishop have good winning chances in practice because the defense is difficult. Ulf Andersson won the position twice within a year, once against a grandmaster and once against a candidate master; and grandmaster Keith Arkell has won it 27 times out of 27. [1] [2] In positions that have a forced win, up to 59 moves are required. [3] Tony Kosten has seen the endgame many times in master games, with the stronger side almost always winning. [4] Pal Benko called this the "headache ending." [5] David Howell observed, "Especially below elite grandmaster level, this is one of the hardest endgames to draw." [6]
Being a five-piece endgame, the rook and bishop versus rook endgame has been fully analysed using computers. Endgame tablebases show that 40.1% of the legal positions with this material are theoretical wins, but that includes many unnatural positions that are unlikely to occur in games. Edmar Mednis estimated that less than 4% of starting positions that occur in games are theoretical wins. [7]
In 1749 François-André Danican Philidor (1726–1795) published a position in which the superior side can force a win. Giambattista Lolli (1698–1769) studied a similar position with a forced win. On the other hand, there are several drawing techniques possible if a winning position such as the Philidor position has not been reached. The Cochrane Defense was discovered by John Cochrane (1798–1878), the Szén position was discovered by József Szén (1805–1857), and there is the second- rank defense. Other winning and drawing positions were studied by Adolf Zytogorski, [8] Tassilo von Heydebrand und der Lasa, Josef Kling and Kuiper, and André Chéron. [9]
Many of the longest chess games on record involve this endgame since at one time the fifty-move rule under which a draw could be claimed after fifty moves with no capture was extended to one-hundred moves for this combination of material. [10] For example, the longest tournament game on record is a 269-move game by Ivan Nikolić and International Master Goran Arsović. [11] The last 103 moves had this material and the game ended in a draw.
Anatoly Karpov played a rook versus rook and bishop ending in a 2003 game with 15-year-old Teimour Radjabov, which went 113 moves before an indignant Karpov claimed a draw by invoking the 50-move rule with only 14 seconds remaining on the game clock. [12] [13] [ failed verification ]
This famous position was studied by and named after François-André Danican Philidor. White wins because his king has reached the sixth rank and the black king is poorly placed (opposite the white king). [14] If this type of position arises, it is usually because of inferior defense. Nevertheless, it is tricky to win. [15]
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First to be noted is that the trivial
does not work because of
which is stalemate (draw). Alternatively, if the bishop does not take the rook, then the white king has to move and White loses the advantage position.
The winning method is as follows:
Threatening to switch the rook to the other side and checkmate.
This is the best place for the black rook. Alternatives are:
This idle move is necessary because the black rook must remain on the e-file, so it is forced to its next best position on e1. White will take advantage of this on move 5.
The winning line only works if the white rook is on b7 or f7.
Or 4...Kc8 5.Ra7 Rb1 6.Rf7 Kb8 7.Rf8+ Ka7 8.Ra8+ Kb6 (White wins because the chessboard has only eight files ) 9.Rb8+.
This is the key idea. It forces the black rook to the inferior third rank while preventing 5...Rd1+. Black is in zugzwang.
If instead 5...Kc8, then 6.Rb4 Kd8 7.Rf4 Re1 (or 7...Kc8 8.Bd5 Kb8 9.Ra4) 8.Ba4 Kc8 9.Bc6 Rd1+ 10.Bd5 Kb8 11.Ra4. Now White completes the following maneuvers, getting the bishop back to d5 with gain of tempo.
If 8...Ke8, then 9.Rg7 and checkmate on g8 next move, else loss of the rook since the bishop covers f3.
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This is the position White was seeking; White threatens 12.Be6+ Kd8 13.Rb8+ Rc8 14.Rxc8#.
If 11...Rd3 12.Ra4 and the black rook cannot prevent Ra8# because b3 is covered by the bishop.
Stopping the check on d3 and cutting off the rook entirely. Now mate is unavoidable either by Ra8# or via Be6+ after Kc8. [16] [17] [18]
This is an exercise in domination of the black rook. This method works if the kings are on the central four ranks or files. It does not work if the kings are on the rank or file next to the edge – those positions are a theoretical draw, but difficult to defend. If the kings are on a rank or file on the edge of the board the position is a win, but by a different method. [19]
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This winning position was discovered by Giambattista Lolli. [20] The position is one rank or file closer to the edge of the board than the Philidor position, so the winning method is slightly different. Switching the attacking rook to the other side of the king is no longer dangerous. [21]
The method:
Or 8...Rb8.
The Cochrane Defense is a drawing method discovered by John Cochrane. The Cochrane Defense is the most popular among grandmasters for this endgame. [23] The basic idea is to pin the bishop to its king when there are at least two ranks or files between it and the defending king.
Accurate play is required for the defense. The defense is most effective near the center of the board, and does not work on the edge. [24] The Cochrane Defense works when:
The Cochrane defense can also be used with a rook against a rook and knight. [26]
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The defense is most effective near the center of the board. In this position, if the pieces on the e-file were moved to the f-file, then if 1.Ke5, the response 1...Kg8 puts the black king dangerously close to the corner. [27]
In this position from a 1991 game between Alexandar Budnikov and Maxim Novik, White would like to get his king to d6 and bishop to d5, to win by a method of Philidor (see Philidor position); however, the pin of the bishop to the king prevents it. If White plays 1.Kd5 or 1.Kf5 then Black moves his king in the opposite direction, so if the bishop then moves, the black rook cuts off the white king. [28]
There are some key ideas for the defender to observe:
The game continued:
and the position is back to the basic Cochrane position, rotated 90 degrees, and the fifty-move rule is closer to coming into effect. The Budnikov versus Novik game continued, with the Cochrane position being reached again. Eventually a draw was claimed by the fifty-move rule. [29]
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The Cochrane Defense was also used in this 1982 game [30] between Ljubomir Ljubojević and Lajos Portisch. The Cochrane position occurred again on move 114, rotated 90 degrees. The game was drawn on move 127. [31]
The defending king goes the opposite way as the attacking king.
Cochrane position again, on a different side. [32]
The "second-rank defense" is a passive defense with the defending king and rook on a rank or file one over from the edge of the board (e.g. the second or seventh rank or the b- or g-file). The method is reliable but it is possible to go wrong, especially if the defending king is near the corner. [33]
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This 1997 game between Joose Norri and Suat Atalık illustrates the second-rank defense. [34] White cannot reach the Cochrane Defense. Attempting to get the rook behind the black king would get to a lost Philidor position: 87.Rc8? Rb2+ 88.Kf1 Rf2+ 89.Ke1 Kd3. White uses the second-rank defense. White alternates his rook between c2 and d2 until Black tries to penetrate.
The defending king can be driven to the edge of the board but then the attacker's rook is under attack, so the king cannot approach.
This is another attempt by Black. It seems that White is in zugzwang and any rook move loses (93.Rc1 Rh2+ 94.Kd1 Kd3), but White has a good move.
Now if 93...Kd3 White has a stalemate defense with 94.Rd2+ so the black king has to back off.
and the game was drawn on move 98. [35]
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The second-rank defense was used by 16-year-old Magnus Carlsen in this 2007 game against Loek van Wely. [36]
It is hard to drive the defending king to the edge. After 65...Rh2+ 66.Kd1 the black rook must move and the white king goes back to e2.
White was in zugzwang and had to temporarily leave the second rank.
Here 66...Kd3 is met by 67.Rd2+.
and the king is back to the second rank. The game continued and the position on move 74 was a reflection of the position on move 66. On move 80 the same defense was set up on the b-file. Black could make no progress and the game was drawn after 109 moves. [37]
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József Szén discovered the Szén position, a defensive drawing position. The kings are opposite in an L-shape and the weaker side's rook defends on the side of his king that has more room. [38] Szén's position is the most important for over-the-board players. Compared to the Philidor position, the kings are not opposite each other and the defending rook can prevent checkmate. The position is a draw only if there is enough room for the defending king on the side with the rooks. [39]
An example of this defense being used in a game is this 1982 one between József Pintér and Yuri Razuvayev. [40] After 88 moves, the position had a rook and bishop versus a rook. The diagram shows the position after 101. Kd1!, reaching the Szén position. On the 132nd move, White reached a Szén position for the fourth time. The game was drawn on the 138th move. [41]
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In the second Lolli position, the kings are one row closer to the edge than in the first Lolli position. Unlike the Philidor position and the first Lolli position, this position is a theoretical draw. Several of the moves in the perfect defence are the only move that saves the game. [42]
The endgame is the final stage of a chess game which occurs after the middlegame. It begins when few pieces are left on the board.
The Lucena position is one of the most famous and important positions in chess endgame theory, where one side has a rook and a pawn and the defender has a rook. Karsten Müller said that it may be the most important position in endgame theory. It is fundamental in the rook and pawn versus rook endgame. If the side with the pawn can reach this type of position, they can forcibly win the game. Most rook and pawn versus rook endgames reach either the Lucena position or the Philidor position if played accurately. The side with the pawn will try to reach the Lucena position to win; the other side will try to reach the Philidor position to draw.
Checkmate is any game position in chess and other chess-like games in which a player's king is in check and there is no possible escape. Checkmating the opponent wins the game.
Triangulation is a tactic used in chess to put one's opponent in zugzwang. Triangulation is also called losing a tempo or losing a move.
The Philidor position is a chess endgame involving a drawing technique for the defending side in the rook and pawn versus rook endgame. This technique is known as the third-rank defense due to the positioning of the defending rook. It was analyzed by François-André Danican Philidor in 1777. Many rook and pawn versus rook endgames reach either the drawn Philidor position or the winning Lucena position. The defending side should try to reach the Philidor position; the attacking side should try to reach the Lucena position. Said grandmaster Jesús de la Villa, "[The Lucena and Philidor positions] are the most important positions in this type of endgame [...] and in endgame theory."
The Tarrasch rule is a general principle that applies in the majority of chess middlegames and endgames. Siegbert Tarrasch (1862–1934) stated the "rule" that rooks should be placed behind passed pawns – either the player's or the opponent's. The idea behind the guideline is that (1) if a player's rook is behind his passed pawn, the rook protects it as it advances, and (2) if it is behind an opponent's passed pawn, the pawn cannot advance unless it is protected along its way.
The chess endgame with a king and a pawn versus a king is one of the most important and fundamental endgames, other than the basic checkmates. It is an important endgame for chess players to master, since most other endgames have the potential of reducing to this type of endgame via exchanges of pieces. Players need to be able to determine quickly whether a given position is a win or a draw, and to know the technique for playing it. The crux of this endgame is whether or not the pawn can be promoted, so checkmate can be forced.
In chess, a fortress is an endgame drawing technique in which the side behind in material sets up a zone of protection that the opponent cannot penetrate. This might involve keeping the enemy king out of one's position, or a zone the enemy cannot force one out of. An elementary fortress is a theoretically drawn position with reduced material in which a passive defense will maintain the draw.
The bishop and knight checkmate in chess is the checkmate of a lone king by a king, a bishop, and a knight. With the stronger side to move and with perfect play, checkmate can be forced in at most thirty-three moves from any starting position where the defender cannot quickly win one of the pieces. The exception is the "stalemate trap". These exceptions constitute about 0.5% of the positions. Checkmates are possible with the defending king on any square at the edge of the board but can be forced only from positions with different material or if the defending king is in a corner controlled by the bishop or on a square on the edge next to a corner; however, mate adjacent to the corners not controlled by the bishop is only two moves deep, so it is not generally encountered unless the defending side plays inaccurately. Although this is classified as one of the four basic or elementary checkmates, it occurs in practice only approximately once in every 6,000 games.
The rook and pawn versus rook endgame is a fundamentally important, widely studied chess endgame. Precise play is usually required in these positions. With optimal play, some complicated wins require sixty moves to either checkmate, capture the defending rook, or successfully promote the pawn. In some cases, thirty-five moves are required to advance the pawn once.
The chess endgame of a queen versus pawn is usually an easy win for the side with the queen. However, if the pawn has advanced to its seventh rank it has possibilities of reaching a draw, and there are some drawn positions with the pawn on the sixth rank. This endgame arises most often from a race of pawns to promote.
In chess, a swindle is a ruse by which a player in a losing position tricks their opponent and thereby achieves a win or draw instead of the expected loss. It may also refer more generally to obtaining a win or draw from a clearly losing position. I. A. Horowitz and Fred Reinfeld distinguish among "traps", "pitfalls", and "swindles". In their terminology, a "trap" refers to a situation where players go wrong through their own efforts. In a "pitfall", the beneficiary of the pitfall plays an active role, creating a situation where a plausible move by the opponent will turn out badly. A "swindle" is a pitfall adopted by a player who has a clearly lost game. Horowitz and Reinfeld observe that swindles, "though ignored in virtually all chess books", "play an enormously important role in over-the-board chess, and decide the fate of countless games".
The opposite-colored bishops endgame is a chess endgame in which each side has a single bishop and the bishops reside on opposite-colored squares. Without other pieces besides pawns, these endings are widely known for their tendency to result in a draw. These are the most difficult endings in which to convert a small material advantage to a win. With additional pieces, the stronger side has more chances to win, but not as many as when bishops are on the same color.
A pawnless chess endgame is a chess endgame in which only a few pieces remain, and no pawns. 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. 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.
Much literature about chess endgames has been produced in the form of books and magazines. A bibliography of endgame books is below.
Giambattista Lolli was an Italian chess player and one of the most important chess theoreticians of his time. He is most famous for his book Osservazioni teorico-pratiche sopra il giuoco degli scacchi, published 1763 in Bologna. Born in Nonantola, Modena, he was one of the Modenese Masters. The checkmate pattern "Lolli's mate" involves infiltrating an opponent's fianchetto position using both a pawn and queen, and is named after Giambattista Lolli.
In a chess endgame of a king, bishop, and pawn versus king, a wrong rook pawn is a rook pawn whose promotion square is the opposite color from the bishop's square color. Since a side's rook pawns promote on opposite-colored squares, one of them may be the "wrong rook pawn". This situation is also known as having the wrong-colored bishop or wrong bishop. In many cases, the wrong rook pawn will only draw, when any other pawn would win. This is because the defending side can sometimes get their king to the corner in front of the pawn, after which the attacking side cannot chase the king away to enable promotion. A fairly common defensive tactic is to reach one of these drawn endgames, often through a sacrifice.
In a chess endgame, a wrong bishop is a bishop that would have been better placed on the opposite square color. This most commonly occurs with a bishop and one of its rook pawns, but it also occurs with a rook versus a bishop, a rook and one rook pawn versus a bishop, and possibly with a rook and one bishop pawn versus a bishop.
Luigi Centurini was an Italian jurist, chess player, and chess composer.(Zavatarelli 2015:19)
The 20th season of the Top Chess Engine Championship began on 1 December 2020 and ended on 1 February 2021. The defending champion was Stockfish, which defeated Leela Chess Zero in the previous season's superfinal. The season 20 superfinal was a rematch between the same two engines. Stockfish once again came out ahead, winning by 6 games.