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This article uses algebraic notation to describe chess moves.

In chess, opposition (or direct opposition) is the situation occurring when two kings face each other on a rank or file, with only one square in between them. In such a situation, the player not having to move is said to "have the opposition" (Flear 2004:12). It is a special type of zugzwang and most often occurs in endgames with only kings and pawns (Flear 2000:36). The side with the move may have to move the king away, potentially allowing the opposing king access to important squares.

There are extensions of direct opposition, such as diagonal opposition and distant opposition, which can be conducive to reaching direct opposition. All three types may be referred to simply as opposition if the type is unambiguous in context.

Contents 1 Direct opposition 2 Purpose 3 Example 4 Diagonal opposition 5 Distant opposition 6 See also 7 References 8 Further reading

Direct opposition is when the two kings face each other along a rank or file with only one square in between. When the term opposition is used, it normally refers to direct opposition.

In this diagram, whoever's turn it is not to move has the opposition. If it is Black's turn to move, White has the opposition and wins (Flear 2004:23). (See King and pawn versus king endgame). If it was White's turn to move, Black would have the opposition and the game would be a draw.

Yuri Averbakh pointed out that the opposition is a means to an end; the end is penetration to a key square (Averbakh 1987:5). This can be a square in front of a pawn, so the king can lead it to the queening square, or into a critical zone to win an enemy blocked pawn. In the diagram on the right, White should play 1. Kc5; taking the opposition by 1. Ke4 draws.

In the 1959 game between Svetozar Gligorić and Bobby Fischer, Black can draw by keeping the white king from getting to any of the key squares. This is accomplished by not allowing White to get the opposition, and seizing the opposition if the white king advances.

• 1... Kb8!

This is the only move to draw. Other moves allow White to get the opposition and then get to a key square, for example 1... Kb7? 2. Kb5, then the black king moves and the white king gets to a key square and then wins by forcing promotion of the pawn.

• 2. Kc5 Kc7!
• 3. Kb5 Kb7!
• 4. Ka5 Ka7! and Black draws (Müller & Lamprecht 2000:20).

Opposition along a diagonal (instead of a rank or file) is called diagonal opposition. Sometimes diagonal opposition is used to achieve direct opposition. An example is the position in the diagram on the left, with Black to move. White has the direct opposition in this position, but it does him no good because his king can not attack the black pawn after the black king moves away. White needs to achieve direct opposition closer to the pawn.

• 1. ... Kf8
• 2. Kd6 and White has the diagonal opposition (diagram on the right).
• 2. ... Ke8
• 3. Ke6 White now has direct opposition on a useful square, and White wins:
• 3. ... Kf8
• 4. Kd7 Kg8
• 5. Ke7 Kh8
• 6. f6 gxf6
• 7. Kf7 or 7. Kxf6 win for White (Flear 2004:33).

Distant opposition is when the kings face off over a longer distance. If there are an odd number of squares between the kings, the player not having the move has the (distant) opposition. As with diagonal opposition, it is often converted to direct opposition, as in the diagram on the right (Capablanca & de Firmian 2006:41):

1. Ke2 (White takes the distant opposition) ... Ke7
2. Ke3 Ke6
3. Ke4 (takes the direct opposition, and now Black must step aside) Kd6 (... Kf6 allows the corresponding Kf4!)
4. Kd4! (Kf5 would lead to both pawns queening) Kc6 (... Ke6 5. Kc5 and is way ahead in the queening race)
5. Ke5 (and White has a choice of which pawn he wins, and then use this as the outside passed pawn unless he can promote it directly)

Black can be tricky and try

1. ... Kf8 and if
2. Ke3 then Ke7 and now Black has the distant opposition and draws. Similarly 2. Kf3 Kf7.

White instead should remember that the aim of the opposition is to penetrate, so step sideways and forward with

1. ... Kf8
2. Kd3! Ke7 (otherwise White penetrates with Kc5, and will win a queening race)
3. Ke3! (White again has the distant opposition and transposes into the main line)

This position is very similar to the previous position. The main line is:

1. Kg2 (taking the distant opposition) Kg7
2. Kg3 Kg6
3. Kg4 Kh6 (and since the black king has been forced to step aside to the h-file, White can now penetrate on the f file)
4. Kf5! Kg7 (... Kh5 5.Rh1#)
5. Kg5 Kh7
6. Kf6 Kg8 (... Kh8 7. Kf7 Kh7 Rh1#)
7. Kg6 Kh8
8. Rf8#

Again, if Black is tricky, he can try

1. ... Kh8 (again, white penetrates)
2. Kf3! (Kg3 Kg7; Kh3 Kh7 give Black the distant opposition) Kg7 (Kh7 3. Kf4!)
3. Kg3.

• Chess terminology
• Zugzwang
• Triangulation
• Corresponding squares
• King and pawn versus king endgame
• Endgame

• Averbakh, Yuri (1987), Comprehensive Chess Endings: Pawn Endings, vol. 4, Pergammon, ISBN 0-08-026906-0
• Capablanca, Jose & de Firmian, Nick (2006), Chess Fundamentals (Completely Revised and Updated for the 21st Century), Random House, ISBN 0-8129-3681-7

• Flear, Glenn (2000), Improve Your Endgame Play, Everyman Chess, ISBN 1-85744-246-6

• Flear, Glenn (2004), Starting Out: Pawn Endings, Everyman Chess, ISBN 1-85744-362-4

• Müller, Karsten & Lamprecht, Frank (2000), Secrets of Pawn Endings, Everyman Chess, ISBN 1-85744-255-5

• Nunn, John (2007), Secrets of Practical Chess (second ed.), Gambit Publications, ISBN 978-1-904600-70-1 pages 113-18