King's RepositoryのロゴKing's Repository

Chess/The Endgame/King and Queen vs. King

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8 a8 black king b8 black king c8 black king d8 black king e8 black king f8 black king g8 black king h8 black king 8
7 a7 black king b7 black king c7 black king d7 black king e7 black king f7 black king g7 black king h7 black king 7
6 a6 black king b6 black king c6 black king d6 black king e6 black king f6 black king g6 black king h6 black king 6
5 a5 black king b5 black king c5 black king d5 black king e5 black king f5 black king g5 black king h5 black king 5
4 a4 black king b4 black king c4 black king d4 black king e4 black king f4 black king g4 black king h4 black king 4
3 a3 black king b3 black king c3 black king d3 black king e3 black king f3 black king g3 black king h3 black king 3
2 a2 black king b2 black king c2 black king d2 black king e2 black king f2 black king g2 black king h2 black king 2
1 a1 white king b1 white queen c1 black king d1 black king e1 black king f1 black king g1 black king h1 black king 1
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Sample starting position for K+Q vs. K mate

Delivering checkmate with a king and queen against a lone king is quite easy. The basic technique involves driving the king to the edge of the board, which the queen can do by herself. It's faster if you use your king and queen together, but this increases the probability of a stalemate, so beginners should do it without the king. The technique described below will accomplish the mate in about 10 to 15 moves.

Here's an example (see diagram on right):

1.Qb5

Cutting the black king off along the fifth rank.

1...Ke6

1...Kc7 2.Qa6 limits Black's king to the last two ranks.

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8 a8 black king b8 black king c8 black king d8 black king e8 black king f8 black king g8 black king h8 black king 8
7 a7 black king b7 black king c7 black king d7 black king e7 black king f7 black king g7 black king h7 black king 7
6 a6 black king b6 black king c6 black king d6 black king e6 black king f6 black king g6 black king h6 black king 6
5 a5 black king b5 black king c5 white queen d5 black king e5 black king f5 black king g5 black king h5 black king 5
4 a4 black king b4 black king c4 black king d4 black king e4 black king f4 black king g4 black king h4 black king 4
3 a3 black king b3 black king c3 black king d3 black king e3 black king f3 black king g3 black king h3 black king 3
2 a2 black king b2 black king c2 black king d2 black king e2 black king f2 black king g2 black king h2 black king 2
1 a1 white king b1 black king c1 black king d1 black king e1 black king f1 black king g1 black king h1 black king 1
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Position after 2.Qc5

2.Qc5 (see diagram)

During this phase, notice how White's queen always stays a knight's move away from the black king, and how no checks are necessary (or even desirable). Moves like 2.Qc6+? only allow Black's king more freedom after 2...Ke5.

2...Kf6 3.Qd5 Kg6 4.Qe5 Kf7

After 4...Kh6 5.Qg3 White's goal has been achieved: the black king is trapped on the edge. White will then bring his king to f6 to force mate.

5.Qd6 Kg7 6.Qe6 Kh7

Black's king is forced to the edge of the board no matter what he does, e.g. 6...Kf8 7.Qd7.

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8 a8 black king b8 black king c8 black king d8 black king e8 black king f8 black king g8 black king h8 black king 8
7 a7 black king b7 black king c7 black king d7 black king e7 black king f7 black king g7 black king h7 black king 7
6 a6 black king b6 black king c6 black king d6 black king e6 black king f6 black king g6 black king h6 black king 6
5 a5 black king b5 black king c5 black king d5 black king e5 black king f5 black king g5 black king h5 black king 5
4 a4 black king b4 black king c4 black king d4 black king e4 black king f4 black king g4 white queen h4 black king 4
3 a3 black king b3 black king c3 black king d3 black king e3 black king f3 black king g3 black king h3 black king 3
2 a2 black king b2 white king c2 black king d2 black king e2 black king f2 black king g2 black king h2 black king 2
1 a1 black king b1 black king c1 black king d1 black king e1 black king f1 black king g1 black king h1 black king 1
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Position after 8.Kb2

7.Qg4 Kh6 8.Kb2 (see diagram)

Now that Black's king is stuck, the white monarch comes in to finish off his adversary.

8...Kh7 9.Kc3

9.Qg5 doesn't spoil anything, but it isn't necessary. Unlike the king and rook vs. king mate, here Black's king doesn't have to be trapped in the corner.

9...Kh8 10.Kd4

10.Qg6?? stalemate was what Black was hoping for. Beware of this trap!

10...Kh7 11.Ke5 Kh8 12.Kf6 Kh7 13.Qg7#.

A detailed analysis of this endgame based on the computer-generated database is in Analysis of KQK Endgame. This shows that for any "King and Queen vs. King" endgame, white to move can force checkmate in at most ten moves.

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8 a8 black king b8 black king c8 black king d8 black king e8 black king f8 black king g8 black king h8 black king 8
7 a7 black king b7 black king c7 black king d7 black king e7 black king f7 black king g7 white queen h7 black king 7
6 a6 black king b6 black king c6 black king d6 black king e6 black king f6 white king g6 black king h6 black king 6
5 a5 black king b5 black king c5 black king d5 black king e5 black king f5 black king g5 black king h5 black king 5
4 a4 black king b4 black king c4 black king d4 black king e4 black king f4 black king g4 black king h4 black king 4
3 a3 black king b3 black king c3 black king d3 black king e3 black king f3 black king g3 black king h3 black king 3
2 a2 black king b2 black king c2 black king d2 black king e2 black king f2 black king g2 black king h2 black king 2
1 a1 black king b1 black king c1 black king d1 black king e1 black king f1 black king g1 black king h1 black king 1
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The final checkmate.