Back-rank checkmate

In chess, a back-rank checkmate is a checkmate delivered by a rook or queen along a back rank (that is, the row on which the pieces (not pawns) stand at the start of the game) in which the mated king is unable to move up the board because the king is blocked by friendly pieces (usually pawns) on the second rank (Burgess 2009:16). A typical position is shown to the right.^{[citation needed]} It is also known as the corridor mate.

Back-rank checkmates
From Burgess, p. 16 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 White wins with 1.Rd8#	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 Back-rank mate after 22.Qxe8#. White captured the black rook on e8 with his queen.

Introduction

Back-rank mates occur quite often in games at fairly low levels, as it occurs out of carelessness. This is because beginners typically lack the skill to realize that such a fate could occur based on the laws of the game. At higher levels of play, though the mate itself does not occur very often, play is often affected by the possibility of it—the fact that a player has to spend time guarding against the mate may leave him vulnerable to other tactical ideas.

	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

Back-rank mates are often guarded against simply by virtue of a friendly rook or queen protecting the back rank. However, it may be possible for the attacking side to deflect one of these pieces away from defensive duties. In the example shown to the left, for example, White to move can play 1.Qxc6 when black cannot reply 1...Rxc6 because of 2.Rd8+ Rxd8 3.Rxd8# with a back-rank mate. Black therefore loses his bishop for no compensation-and Black has no good continuation because of the threat to chew up more material with Qxa8 or Qxc8. For example, 1...Qa6 2.Qxa8! Rxa8 3.Rd8+ Rxd8 4.Rxd8#. If Black tries to defend the back rank so that White's queen and bishop are skewered, White can keep an extra piece, for example 1...b5 (defending d8 with the queen) 2.Qf3! keeping the rook on c8 stuck to the defense of the rook on a8, or 1...g6 (creating luft) 2.Qf6! and Black still can't take on pain of a back-rank mate. Examples such as this, where a rook cannot leave the back rank because of mate threats, are relatively common in chess.

Back-rank threats can be guarded against more permanently by moving one of the pawns in front of the king to give the king a flight square (such a move is sometimes said to "give the king some luft"). If it were Black to play in the example to the left, he could counter White's threat with (among other moves) 1...g6, giving the king a square on g7 to which he could safely move. Note, however, that 1...h6 in this example would not do the job, as after the d3 rook moves the h7 square is guarded by the white bishop.

It is often not a good idea to play such pawn moves unless there is a pressing need to do so, as they can represent a loss of time. In many chess openings, however, they are often played for some other purpose, before any back-rank threats have emerged (...h6 is often played to bother a white bishop on g5, for example. Also see Fianchetto).

Example from game by Capablanca

Bernstein vs. Capablanca, 1914

	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

Position after White's 29th move.

One of José Raúl Capablanca's most famous games featured a variety of back-rank threats at the end. It was an exhibition game played in Moscow in 1914 against Ossip Bernstein (Capablanca had the black pieces). The position shown to the right was reached after White's 29th move. Capablanca now played 29...Qb2! The simplest point is that 30.Qxb2 is not possible because of the back-rank mate 30...Rd1#, but there are several related ideas: for example, 30.Qe1, apparently defending the threatened rook, loses to 30...Qxc3 (if 31.Qxc3 then ...Rd1+ 32.Qe1 Rxe1#); 30.Rc2 fails to 30...Qb1+ 31.Qf1 Qxc2; and 30.Qc2 loses to 30...Qa1+ 31.Qc1 Rd1+ 32.Qxd1 Qxd1#, or 30...Qxc2 31.Rxc2 Rd1#. After 30.Rc8 it looks like white may turn the tables as 30...Rxc8? allows 31.Qxb2 to win a queen for a rook, however Capablanca has 30...Qa1+ (or Qb1+) when instead White loses a rook after 31.Qf1 Qxf1+ 32.Kxf1 Rxc8.

Note that had Capablanca played for the back-rank mate more directly with 29...Qb1+ 30.Qf1 Rd1?? (30...Qxa2 would be sensible), he would himself have lost to the back-rank mate 31.Rc8+ Rd8 32.Rxd8#.

References

• Burgess, Graham (2009), The Mammoth Book of Chess (3rd ed.), Running Press, ISBN 978-0-7624-3726-9 
• Hooper, David; Whyld, Kenneth (1992), The Oxford Companion to Chess (2nd ed.), Oxford University Press, ISBN 0-19-866164-9 
• Schiller, Eric (1999), Encyclopedia of Chess Wisdom (1st ed.), Cardoza Publishing, ISBN 0940685930 

External links

• How to Play Chess:Back-rank mate audio.