Losing chess

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a b c d e f g h
8
Chessboard480.svg
a8 black rook
b8 black knight
d8 black queen
e8 black king
f8 black bishop
g8 black knight
h8 black rook
a7 black pawn
b7 black bishop
c7 black pawn
d7 black pawn
e7 black pawn
f7 black pawn
g7 black pawn
h7 black pawn
b5 white bishop
e3 white pawn
a2 white pawn
b2 white pawn
c2 white pawn
d2 white pawn
f2 white pawn
g2 white pawn
h2 white pawn
a1 white rook
b1 white knight
c1 white bishop
d1 white queen
e1 white king
g1 white knight
h1 white rook
8
7 7
6 6
5 5
4 4
3 3
2 2
1 1
a b c d e f g h
White to move, must play Bxd7. Then Black must also capture, but has the option of doing so with either Nxd7, Qxd7, Kxd7, or Bxg2.

Losing chess (also known as Antichess, the Losing Game, Giveaway chess, Suicide chess, Killer chess, Must-Kill, or Take-all chess) is a chess variant in which the objective of each player is to lose all of his pieces or be stalemated, that is, a misère version. In some variations, a player may also win by checkmating or by being checkmated. Losing chess is one of the most popular of all chess variants.[1]

The origin of the game is unknown, but believed to significantly predate an early version, named Take Me, played in the 1870s. Because of the popularity of Losing chess, several variations have spawned. The most widely played (main variant) is described in Popular Chess Variants by D. B. Pritchard.


Rules (main variant)[edit]

The rules are the same as those for standard chess, except for the following special rules:

  • Capturing is compulsory.
  • When more than one capture is available, the player may choose.
  • The king has no royal power and accordingly:
  • In addition to its normal promotion options, a pawn may promote to a king.
  • Stalemate is a win for the stalemated player.

A player wins by losing all his pieces, or being stalemated. Apart from move repetition, draw by agreement, and the fifty-move rule, the game is also drawn when a win is impossible (such as if a dark-squared bishop and a light-squared bishop are the only pieces remaining).

Analysis[edit]

a b c d e f g h
8
Chessboard480.svg
a8 black rook
b8 black knight
c8 black bishop
d8 black queen
e8 black king
f8 black bishop
g8 black knight
h8 black rook
a7 black pawn
b7 black pawn
c7 black pawn
e7 black pawn
f7 black pawn
g7 black pawn
h7 black pawn
d6 black pawn
e3 white pawn
a2 white pawn
b2 white pawn
c2 white pawn
d2 white pawn
f2 white pawn
g2 white pawn
h2 white pawn
a1 white rook
b1 white knight
c1 white bishop
d1 white queen
e1 white king
f1 white bishop
g1 white knight
h1 white rook
8
7 7
6 6
5 5
4 4
3 3
2 2
1 1
a b c d e f g h
After 1.e3 d6?? White wins with: 2.Qg4! Bxg4 3.Kd1 Bxd1 4.a3 Bxc2 5.Ra2 Bxb1 6.a4 Bxa2 7.b3 Bxb3 8.g3 Bxa4 9.Bb5 Bxb5 10.Ne2 Bxe2 11.Rf1 Bxf1 12.h3 Bxh3 13.g4 Bxg4 14.f3 Bxf3 15.e4 Bxe4 16.d3 Bxd3 17.Bh6 Nxh6 1–0[2]

Because of the forced capture rule, Losing chess games often involve long sequences of forced captures by one player. This means that a minor mistake can doom a game. Losing openings for White include 1.e4, 1.d4, 1.d3, 1.Nf3, 1.Nc3, 1.f4, 1.h4, 1.b4, and 1.h3. Some of these openings took months of computer time to solve, but the wins against 1.e4, 1.d4, and 1.d3 consist of a single series of forced captures and can be played from memory by most experienced players.[a]

Work to weakly solve the main variant of Losing chess is ongoing. As of September 2014 it has been found that, with perfect play, White is able to force a win after 18 of Black's 20 legal responses to 1.e3. The outcomes of the remaining two (1...b6 and 1...c5) are currently unsolved.[3]

In the example diagram, 2...d6?? is a blunder since White can easily force victory. In this sequence, each move by Black (from 2...Bxg4 through 16...Bxd3) is the only legal move available.

Variations[edit]

Variations regarding stalemate[edit]

a b c d e f g h
8
Chessboard480.svg
g8 black knight
h8 white bishop
g7 white pawn
e5 black pawn
c4 black pawn
e4 white pawn
c3 white pawn
8
7 7
6 6
5 5
4 4
3 3
2 2
1 1
a b c d e f g h
White to move, but there are no legal moves. This position is stalemate. The result of this game would depend on the variant being played.

Implementations of the main variant can vary in regard to stalemate. "International" rules are as described above, with the stalemated player winning. FICS rules resolve stalemate as a win for the player with the fewer number of pieces remaining; if both have the same number, it is a draw (the piece types are irrelevant). "Joint" FICS/International rules resolves stalemate as a draw unless it is a victory for one player under both rulesets.[3] The stalemate in the diagram to the left would be a win for white under "international" rules, a win for black under FICS rules, and a draw under "joint" rules.

Variant 2[edit]

Rules are the same as the main rules, except:[4]

  • Pawns promote only to queens.
  • Stalemate is a draw.

Variant 3[edit]

Rules are the same as the main rules, except:[4]

  • The king has royal powers, and removing the king from check takes precedence over capturing another piece.
  • A player wins by reducing his pieces to just a king, or by checkmating the opponent.
  • Stalemate is a draw.

Variant 4[edit]

Rules are the same as variant 3, except:[4]

  • A player wins by reducing his pieces to just a king, or by getting checkmated.

Kamikaze Chess[edit]

  • A player wins by losing all his pieces, or by checkmating the opponent.
  • The king has royal powers, and removing the king from check takes precedence over capturing another piece.
  • Players must lose their king last. Players must not move into check until they have only the king left.
  • Pawns promote only to queens.

Kamikaze Chess II[edit]

Rules are the same as the main rules, except:

  • Black moves first.
  • Castling is permitted.
  • Pawns may promote to kings.
  • When a player has only a pawn remaining, and the pawn is blocked from advancing, the opponent gets unlimited moves until the pawn is freed.

Losers Chess (ICC)[edit]

There are two major variants, Losers Chess (aka w17) played on ICC, and Suicide Chess on free ICSs. The goal in both games is to lose all of one's pieces, although in Losers Chess, a player can also win by getting checkmated.

Endings[edit]

P. H. Törngren
Tidskrift för Schack, 1929
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8
Chessboard480.svg
a6 black pawn
h2 white pawn
8
7 7
6 6
5 5
4 4
3 3
2 2
1 1
a b c d e f g h

David Pritchard, the author of The Encyclopedia of Chess Variants, wrote that the "complexity and beauty" of Losing chess is found in its endgame. He noted that, in contrast with regular chess, Losing chess endgames with just two pieces require considerable skill to play correctly, whilst three or four pieces endgames can exceed human capacity to solve precisely.[2]

References[edit]

Notes

  1. ^ Solutions by David Bronstein were published in Popular Chess Variants (2000), pp. 33–34:
    • 1.d4?? e5 2.dxe5 Qg5 3.Qxd7 Bxd7 4.Bxg5 Kd8 5.Bxd8 a6 6.Bxc7 Ra7 7.Bxb8 b6 8.Bxa7 a5 9.Bxb6 g6 10.Bxa5 Bb4 11.Bxb4 Ne7 12.Bxe7 Rf8 13.Bxf8 h6 14.Bxh6 g5 15.Bxg5 f6 16.Bxf6 Bh3 17.Nxh3 0–1
    • 1.d3?? g5 2.Bxg5 Bg7 3.Bxe7 Bxb2 4.Bxd8 Bxa1 5.Bxc7 Bc3 6.Bxb8 Rxb8 7.Nxc3 d5 8.Nxd5 Nf6 9.Nxf6 Rg8 10.Nxe8 Rxg2 11.Bxg2 f6 12.Bxb7 Rxb7 13.Nxf6 Rb8 14.Nxh7 Rb1 15.Qxb1 Bb7 16.Qxb7 a6 17.Qxa6 0–1
    • 1.e4?? b5 2.Bxb5 Nf6 3.Bxd7 Nxe4 and White loses no matter which capture he chooses:
      • 4.Bxe8 Qxd2 5.Qxd2 (if 5.Bxf7 Qxc1 6.Qxc1 Nxf2 7.Kxf2 Rg8 etc.) 5...Nxd2 6.Kxd2 Rg8 7.Bxf7 c5 8.Bxg8 g6 9.Bxh7 e5 10.Bxg6 e4 11.Bxe4 Nc6 12.Bxc6 Bb7 13.Bxb7 Rc8 14.Bxc8 a6 15.Bxa6 c4 16.Bxc4 Ba3 17.Nxa3 0–1
      • Or 4.Bxc8 Nxd2 5.Bxd2 Qxd2 6.Qxd2 Na6 7.Bxa6 Rc8 8.Bxc8 f5 9.Bxf5 Rg8 10.Bxh7 c5 11.Bxg8 e6 12.Bxe6 c4 13.Bxc4 a6 14.Bxa6 g5 15.Qxg5 Kd8 16.Qxd8 Be7 17.Qxe7 0–1

Citations

  1. ^ Pritchard (2007), p. 86
  2. ^ a b Pritchard (2000), p. 34
  3. ^ a b Watkins, Mark (10 September 2014). "Solved Openings in Losing Chess". Retrieved 15 January 2015. 
  4. ^ a b c Pritchard (1994), p. 176

Bibliography

External links[edit]