abcdefgh
8
g7 black king
e5 black pawn
f5 black pawn
d4 black queen
g3 white bishop
a2 black pawn
f1 white king
g1 white rook
8
77
66
55
44
33
22
11
abcdefgh
From this position, 1.Bxe5++ is a winning double check.

In chess and other related games, a double check is a check delivered by two pieces simultaneously.[1][2] In chess notation, it is almost always represented the same way as a single check ("+"), but is sometimes symbolized by "++". (The symbol "++", however, is also sometimes used to denote checkmate.[3]) This article uses "++" for double check and "#" for checkmate.

Chess

Gundersen vs. Faul, 1928
abcdefgh
8
a8 black rook
c8 black bishop
d8 black queen
f8 black rook
a7 black pawn
b7 black pawn
e7 black knight
e6 white knight
h6 black king
d5 black pawn
e5 white pawn
f5 black pawn
g5 black pawn
h5 white pawn
b4 black bishop
d4 black knight
g4 white queen
c3 white knight
a2 white pawn
b2 white pawn
f2 white pawn
g2 white pawn
a1 white rook
c1 white bishop
e1 white king
h1 white rook
8
77
66
55
44
33
22
11
abcdefgh
After 14...g7–g5, White mates with a double check by capturing the pawn en passant.

The most common form of double check involves one piece moving to deliver check and revealing a discovered check at the same time from a piece it had been blocking. The only possible reply to a double check is a king move, as it is impossible to block or capture both checking pieces at once.

In exceptional circumstances, it is possible for the moved piece in a double check to not give check. The only way for this to happen in orthodox chess is by way of an en passant capture. In the position shown from Gundersen–Faul, 1928, Black has just played 14...g7–g5. White replies 15.hxg6 e.p.#. The result is a double check even though the white pawn does not give check: one check is given by the rook, discovered by the capturing pawn's move; the other by the bishop, revealed by the captured pawn's removal. Such a double check is extremely rare in practical play, but it is sometimes found in chess problems.

Game examples

A double check is a part of the smothered mate pattern known as Philidor's legacy.

Réti vs. Tartakower, 1910
abcdefgh
8
a8 black rook
b8 black knight
c8 black bishop
e8 black king
f8 black bishop
h8 black rook
a7 black pawn
b7 black pawn
f7 black pawn
g7 black pawn
h7 black pawn
c6 black pawn
e5 black queen
e4 black knight
d3 white queen
a2 white pawn
b2 white pawn
c2 white pawn
d2 white bishop
f2 white pawn
g2 white pawn
h2 white pawn
c1 white king
d1 white rook
f1 white bishop
g1 white knight
h1 white rook
8
77
66
55
44
33
22
11
abcdefgh
Position after 8...Nxe4??

Aron Nimzowitsch wrote, "Even the laziest king flees wildly in the face of a double check."[4] Because the only possible response to a double check is a king move, the double check is often an important tactical motif.[1] A famous example is RétiTartakower, Vienna 1910, which arose after:

1. e4 c6 2. d4 d5 3. Nc3 dxe4 4. Nxe4 Nf6 5. Qd3 e5?! 6. dxe5 Qa5+ 7. Bd2 Qxe5 8. 0-0-0! Nxe4?? (diagram) 9. Qd8+!!

Réti sacrifices a queen in order to set up a double check.

9... Kxd8 10. Bg5++

White mates after 10...Ke8 11.Rd8# or 10...Kc7 11.Bd8#.[5]

Anderssen vs. Dufresne, 1852
abcdefgh
8
b8 black rook
e8 black king
g8 black rook
a7 black pawn
b7 black bishop
c7 black pawn
d7 black pawn
e7 black knight
f7 black pawn
h7 black pawn
b6 black bishop
c6 black knight
f6 white pawn
a4 white queen
a3 white bishop
c3 white pawn
d3 white bishop
f3 black queen
a2 white pawn
f2 white pawn
g2 white pawn
h2 white pawn
d1 white rook
e1 white rook
g1 white king
8
77
66
55
44
33
22
11
abcdefgh
Position after 19...Qxf3?

A double check was also seen in the celebrated Evergreen Game, AnderssenDufresne, 1852.[2] Anderssen won with:

20. Rxe7+! Nxe7 21.Qxd7+!!

A queen sacrifice to set up a deadly double check.

21... Kxd7 22. Bf5++ Ke8

Or 22...Kc6 23.Bd7#.

23. Bd7+ Kf8 24. Bxe7#

Variants

abcdefgh
8
d7 black pawn
a6 white upside-down queen
e6 black king
e5 white pawn
c4 white bishop
d4 white upside-down knight
f4 white upside-down knight
e1 white rook
h1 white king
8
77
66
55
44
33
22
11
abcdefgh
Winning position for White shown with a pawn, a bishop, a rook, two moas (shown as inverted knights) and a grasshopper (shown as inverted queen). After Black moves his only pawn to d5, White taking it en passant with their own pawn results in quintuple check.
abcdefgh
8
e7 black pawn
f7 black king
f5 white pawn
d3 white upside-down knight
f1 white rook
g1 white king
8
77
66
55
44
33
22
11
abcdefgh
Winning position for White shown with a pawn, rook, and a knight-rider (shown as inverted knight). After Black moves his only pawn to e5, White taking it en passant with their own pawn results in triple check.

In chess with variant rules or fairy pieces, other ways of delivering a double check may be possible. Triple, quadruple and even quintuple checks may also be possible.

For example, in the winning position shown to the left, after Black plays 1...d5 to remove the check from the bishop on c4, White plays 2.exd6 e.p.+++++. After the en passant capture, five pieces discover-check the black king: both moas (the moa is a non-leaping knight which first takes a diagonal step, then an orthogonal one), the rook, the grasshopper (the grasshopper captures by leaping over an intervening piece) and the bishop. Black would now be obliged to escape the multi-check and play one of either 2...Kxd6, to recapture White's pawn right away, or passively evade the checks without capturing by playing 2...Kd7 or 2...Kf6.

Another example is shown with the winning position shown on the right, after Black plays 1...e5 to remove the check from the knight-rider on d3, White plays 2. fxe6 e.p.+++. After the en passant capture, three pieces discover-check the black king: the pawn, the knight-rider, and the rook. Black would now be obliged to escape the multi-check by recapturing White's pawn with 2...Kxe6 or passively evading the checks without capturing by playing one of either 2...Ke7, 2...Ke8, 2...Kg6, 2...Kg7, or 2...Kg8.

Xiangqi

In xiangqi, the Chinese version of chess, triple check and even quadruple check are possible, as in the following examples. In janggi (Korean chess), even quintuple and sextuple check are possible as well.

Triple check: Red moved his horse from e5 to d7, giving check and exposing a double check from the chariot and cannon.
Quadruple check: Red moved his chariot from f9 to e9, uncovering two checks from the horses, giving a check of its own, and making a platform for the cannon at e7 to give yet another check. In janggi, using the same pieces and adding two elephants that both attack the general through the chariot's square allows a sextuple check.

References

  1. ^ a b Hooper, David; Whyld, Kenneth (1992), The Oxford Companion to Chess (second ed.), Oxford University Press, p. 113, ISBN 0-19-866164-9
  2. ^ a b Golombek, Harry (1977), Golombek's Encyclopedia of Chess, Crown Publishing, p. 88, ISBN 0-517-53146-1
  3. ^ Tim Just and Daniel Burg, 2003, U.S. Chess Federation's Official Rules of Chess, 5th ed., ISBN 0-8129-3559-4, p. 218
  4. ^ Nimzowitsch, Aron (1947), My System (second ed.), David McKay, p. 130, ISBN 0-679-14025-5
  5. ^ Chernev, Irving (1955), 1000 Best Short Games of Chess, Simon and Schuster, p. 18