King and pawn versus king endgame 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 (Lasker 1915). It is important to master this endgame, since most other endgames have the potential of reducing to this type of endgame via exchanges of pieces. It is important to be able to tell 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 (or queened), so checkmate can be forced. In the first paragraph of one of his books on endgames, Peter Griffiths emphasized the importance of this endgame: There is simply no substitute to a clear understanding of when and how these positions are won or drawn, not only so that one can play them accurately, but in order to recognize in advance what the correct result should be. If you can do that, you can exchange off quite confidently from a more complex position (Griffiths 1976:1). In the positions in which the pawn wins, at most nineteen moves are required to promote the pawn (with optimal play) and at most nine more moves to checkmate, assuming that the pawn was promoted to a queen (Levy & Newborn 1991:144). Except for the section on defending and some actual games, it will be assumed that White has a king and pawn and Black has a lone king. In general, Black should place his king in the path of the pawn to try to prevent its promotion. Contents Rule of the square Key squares Rook pawn Examples from games Pawns other than rook pawns Knight pawn exception Any key square by any route Opposition Rules Case 1, conditions (b) and (c) are met Case 2, conditions (a) and (c) are met Case 3, conditions (a) and (b) are met Example from Maróczy vs. Marshall Case 4, all three conditions are met Exception – rook pawn Defending drawn positions The king is in front of the pawn The king has the opposition The king is on the sixth rank Example from Gligorić versus Fischer Guidelines Examples Kamsky vs. Kramnik See also References External links Rule of the square The most basic rule is when the pawn can queen unassisted by a b c d e f g h its king. The rule of the square determines if this is possible. In this position, the pawn is on the fifth square from the 8 8 queening square (counting the queening square itself). A 7 7 square of 5×5 squares with the queening square in one corner 6 6 and the pawn in an adjacent corner can be imagined. (An easy 5 5 method is to construct the square with a diagonal from the 4 4 pawn to the last rank.) If the black king can move into this square, he can catch the pawn, otherwise the pawn wins the 3 3 race. 2 2 1 1 In this position, if it is Black's move, he can move ...Kb4 and a b c d e f g h enter the square, catching the pawn. If it is White's move, the Rule of the square pawn advances, the square shrinks to 4×4, and the king cannot move into the square, so the pawn queens (Müller & Lamprecht 2007:15). (See Wikibooks – Chess/The Endgame for further discussion on the rule of the square.) Even if the defending king can move inside the square of the pawn, the attacking king may be able to block it, as in the diagram from Fishbein. 1... Ke4 Moving into the square. 2. Kb4! Kd5 3. Kb5! Kd6 4. Kb6! Kd7 5. Kb7! Kd6 6. a5 Kc5 7. a6 Kb5 8. a7 and the pawn promotes (Fishbein 1993:2). From Fishbein a b c d e f g h 8 8 7 7 6 6 5 5 4 4 3 3 2 2 1 1 a b c d e f g h Black to move. Black can move inside the square of the pawn, but the white king can block it. Note that in some cases, the king can catch a pawn when he is Study by Richard Réti, 1921 outside the square by creating threats that must be parried, and a b c d e f g h gain a tempo. In the Réti endgame study (by Richard Réti, 8 8 1921), the white king is outside the square of the black pawn, 7 7 two tempi short of catching the pawn. However, White can draw by "going after two birds at once". 6 6 5 5 1. Kg7! h4 2. Kf6! Kb6 4 4 If 2...h3 then 3.Ke7 or 3.Ke6 and the pawns promote together. 3 3 3. Ke5! Kxc6 2 2 1 1 If 3...h3 then 4.Kd6 h2 5.c7, draw. a b c d e f g h 4. Kf4, resulting in a draw (Dvoretsky 2011:29). White to move draws Key squares If the defending king is within the "square", then the pawn cannot queen without the help of its own king. The first concept that needs to be introduced is that of the key square, also known as a critical square. A key square is a square such that if White's king occupies it, White can force the pawn to promotion, regardless of where the black king is and regardless of which side is to move, and against any defense. The key squares are relative to the position of the pawn. Whether or not the white king can reach a key square depends on the position of the pieces. Of course, even if the white king occupies a key square, accurate play is still required in order to promote the pawn (Müller & Lamprecht 2007:20–22). Note that the key square is in front of the pawn. Endgame expert Yuri Averbakh said, just as a father leads his child across the road rather than pushing the child in front, the king should also lead the pawn to the queening square. Rook pawn A rook pawn (on the a-file or h-file) has much less chance of a b c d e f g h promoting than other pawns. The reason is that if the 8 8 opposing king can get to any square in front of the pawn, it cannot be driven away from the file, and the pawn cannot 7 7 queen. Black can always draw if he can reach the c8-square 6 6 for an a-pawn (pawn on the a-file), or the equivalent f8 for an 5 5 h-pawn, except for the position in the next diagram, with 4 4 White to move. Therefore, an advanced rook pawn generally 3 3 has two key squares: b7 and b8 for an a-pawn, and g7 and g8 for an h-pawn. The key squares are indicated by the black 2 2 dots in the position in the diagram. 1 1 a b c d e f g h If White's king can reach either of the two key squares, he can Dots are key squares for a rook pawn. In keep Black's king away and the pawn will promote. If the addition, Black stops the pawn if the Black king can reach any of the squares marked with a dot or black king gets to any of the squares an "X", it stops the pawn (Silman 2007:105–6). marked "X". The pawn can also promote in the position on the right (if White is a b c d e f g h to move), after 8 8 1. h7 7 7 6 6 However, in practice most of the time the black king can stop a 5 5 rook pawn because it is usually close enough that the white king 4 4 cannot prevent it from getting in front of the pawn (or capturing it). 3 3 2 2 1 1 a b c d e f g h An exception: White to move wins because the pawn promotes after 1.h7. Examples from games The game Oscar Panno–Miguel Najdorf, Buenos Aires 1968,[1] continued 59. Kg4 Kc7 60. Kg5 and White won because the white king can reach the key square g7. Black resigned in light of 60... Kd7 61. Kg6 Ke7 If 61...Ke6, then 62.h4; not 62.Kg7?? because 62...Kf5! wins the pawn. 62. Kg7 Moving to a key square, the only move to win. 62... Ke6 63. h4 Kf5 64. h5 Panno vs. Najdorf The only move to win. The king protects the pawn as it a b c d e f g h promotes. 8 8 7 7 If Black was to move in this position, he would draw by reaching the f8-square and preventing the white king from 6 6 getting to a key square, and the pawn cannot promote (Müller 5 5 & Lamprecht 2007:22). 4 4 3 3 2 2 1 1 a b c d e f g h Position after 58... Kb7, White wins by reaching a key square (dots). This position from a game between Gedeon Barcza and future Barcza vs. Fischer, 1959 [2] world champion Bobby Fischer was a draw. (White's 96.Kd2 a b c d e f g h followed by 97.Kc1 draws.) 8 8 7 7 6 6 5 5 4 4 3 3 2 2 1 1 a b c d e f g h Position after 95...Kxa4 ½–½ Pawns other than rook pawns a b c d e f g h a b c d e f g h 8 8 8 8 7 7 7 7 6 6 6 6 5 5 5 5 4 4 4 4 3 3 3 3 2 2 2 2 1 1 1 1 a b c d e f g h a b c d e f g h Dots indicate key squares for a pawn on Dots indicate key squares for a pawn on the second and third ranks the fourth and fifth ranks a b c d e f g h 8 8 7 7 6 6 5 5 4 4 3 3 2 2 1 1 a b c d e f g h Dots indicate key squares for a pawn on the sixth and seventh ranks Pawns other than rook pawns have a much better chance of promoting.