Stalemate

From Wikipedia, the free encyclopedia

Stalemate is a situation in chess where the player whose turn it is to move has no legal moves but is not in check. Stalemate ends the game, with the result a draw. However, in certain variants, such as suicide chess, stalemate is not necessarily a draw, and is deemed a win for either (a) the player with fewer pieces (a draw results if the players have the same number of pieces) or (b) the stalemated player.

Stalemate has also become a widely used metaphor for other situations where there is a conflict or contest between two parties, such as war or political negotiations, and neither side is able to achieve victory, resulting in what is also called a dead heat, standoff, or deadlock. In that usage, unlike in chess, "stalemate" often refers to a temporary impasse that is ultimately resolved.

Contents 1 Stalemate in chess 1.1 The desperado piece 1.2 Stalemate in studies 1.3 Stalemate in problems 1.3.1 Double stalemate 2 History of the stalemate rule 3 Effect of stalemate on endgames 4 See also 5 Notes 6 References 7 External links

[edit] Stalemate in chess

With Black to move, the black king is stalemated in each of the four positions in the diagram at the right. Stalemate is an important factor in the endgame - the set-up in the top-right of this diagram, for example, quite frequently occurs in play, and the position in the bottom-left is an example of a pawn being worth as much as a queen. (Even if it were White's move, there is no way to avoid this stalemate without allowing Black's pawn to promote. White can, however, win the resulting queen versus queen ending if his king is close enough. For instance, if White's king is on d5 (see algebraic chess notation), he wins with 1. Qd1+ Kb2 2. Qd2+ Kb1 3. Kc4! a1(Q) 4. Kb3, when Black cannot avoid checkmate.) Stalemates of this sort can often save a player from losing an apparently hopeless position.

Stalemate can also occur with more pieces on the board. The position at left occurred in Gelfand-Kramnik, FIDE Candidates match, game 6, Sanghi Nagar 1994. Kramnik (Black), down two pawns and on the defensive, would be very happy with a draw. Gelfand (White) has just played 67. Re7? (from e4), a strong-looking move that threatens 68. Qxf6, winning a third pawn, or 68.Rc7, further constricting Black. Black responded 67... Qc1! If White takes Black's undefended rook with 68. Qxd8, Black draws with 68... Qh1+ 69. Kg3 Qh2+!, forcing 70. Kxh2 stalemate. If White avoids the stalemate with 68. Rxg7+ Kxg7 69. Qxd8, Black draws by perpetual check with 69... Qh1+ 70. Kg3 Qg1+ 71. Kf4 Qc1+! 72. Ke4 Qc6+! 73. Kd3!? (73. d5 Qc4+; 73. Qd5 Qc2+) Qxf3+! 74. Kd2 Qg2+! 75. Kc3 Qc6+ 76. Kb4 Qb5+ 77. Ka3 Qd3+. Gelfand played 68. d5 instead, but still only drew.

[edit] The desperado piece

A piece that is offered as a sacrifice to bring about stalemate is sometimes termed a desperado piece. Many draws have been saved this way — two of the best known examples being the game Evans-Reshevsky, USA 1963 (see diagram on left), where Evans sacrificed his queen and rook on moves 49 and 50, and Pilnick-Reshevsky, U.S. Championship 1942 (see diagram at right).

In Pilnick-Reshevsky, after 1... g4?? 2. Qf2! the white queen is a desperado piece: Black must capture it, resulting in stalemate.

In Evans-Reshevsky, White's rook has been called the eternal rook. Capturing it results in stalemate, but otherwise it stays on the seventh rank and checks Black's king ad infinitum (and a draw by agreement will occur or a draw by threefold repetition or the fifty move rule can eventually be claimed).

Reshevsky also fell into a stalemating trap against Efim Geller in the 1953 Candidates Tournament.[1] In the diagram at right, after 53... Rf3+!, 54. Kxf3 would be stalemate. If 54. Kg2, then 54... Rxg3+! and again White couldn't take the rook without resulting in stalemate, and Black has won a crucial pawn, thus enabling him to draw the ending. In light of these three games, the Russian analyst Verkhovsky observed that Reshevsky apparently suffered from stalemate blindness every 11 years.[2]

Another famous game saved by the possibility of stalemate is Keres-Fischer, Curacao 1962, although Fischer avoided the stalemating lines and allowed Keres to draw by perpetual check instead. In the position shown on the left, Keres played the centralizing 72. Qe5!! Fischer commented:

What's this? He makes no attempt to stop me from queening!? Gradually my excitement subsided. The more I studied the situation, the more I realized that Black had no win.

Now if 72. ... g1(Q), 73. Bf5+ Kg8 (73. ... Kh6?? 74.Qh8#) 74.Qe8+ Kg7 75. Qe7+ Kg8 (75...Kh8?? 76.Qh7#) 76.Qe8+ draws by repetition; if 72. ... Qf2+, 73.Kh3 g1(Q) 74.Bf5+ Kh6 75. Qf6+ Kh5 76. Bg6+! Qxg6 77. Qg5+!! and either capture is stalemate. The game continued 72... Qh1+ 73. Bh3. Now if 73... g1=Q, 74. Qh5+ Kg7 75. Qg6+! and either capture of the queen results in stalemate (see the diagram on the right) — otherwise the white queen keeps checking the black king: 75...Kh8 76. Qh6+ Kg8 77. Qg6+! Kf8 78. Qf6+ Ke8 79. Qe6+, and Black must repeat moves with 79...Kf8, since 79...Kd8?? runs into 80.Qd7#. (Fischer 1969:233)

Sometimes it is possible for the inferior side to sacrifice two or three pieces in rapid succession to achieve a statemate. An example is seen in the diagram at left. Black saved the draw with 1...h3+! 2.Kxh3 Qf5+! 3.Qxf5 not 3.Kg2? Qxd7 Rxg3+! 4.Kh4 Rg4+!

[edit] Stalemate in studies

Stalemate is a frequent theme in endgame studies and other chess compositions. An example is the "White to Play and Draw" problem at left, which was composed by the American master Frederick Rhine in 2005 and published in "Benko's Bafflers" in the May 2006 issue of Chess Life magazine. The main line runs 1.Ne5+! Black wins after 1.Nb4+? Kb5! or 1.Qe8+? Bxe8 2.Ne5+ Kb5! 3.Rxb2+ Nb3. Bxe5 After 1...Kb5? 2.Rxb2+ Nb3 3.Rxc4! Qxe3 (best; 3...Qb8+ 4.Kd7 Qxh8 5.Rxb3+ forces checkmate) 4.Rxb3+! Qxb3 5.Qh1! Bf5+ 6.Kd8! Qxc4 (best) 7.Nxc4 Kxc4 8.Qf3, White will easily draw at least. According to endgame databases, with perfect play by both sides White wins in 62 more moves. 2.Qe8+! 2.Qxe5? Qb7+ 3.Kd8 Qd7#. Bxe8 3.Rh6+ Bd6 3...Kb5 4.Rxb6+ Kxb6 5.Nxc4+ also leads to a drawn endgame. Not 5.Rxb2+? Bxb2 6.Nc4+ Kb5 7.Nxb2 Bh5! trapping White's knight. 4.Rxd6+! Kxd6 5.Nxc4+! Nxc4 6.Rxb6+ Nxb6+ Moving the king is actually a better try, but the resulting endgame of two knights and a bishop against a rook is also drawn with correct play, as shown by Karpov-Kasparov, Tilburg 1991 and confirmed by the Shredder six-piece database. 7.Kd8! (diagram at right) Black is three pieces ahead, but if White is allowed to take the bishop, the two knights are insufficient to force checkmate. The only way to save the bishop is to move it, resulting in stalemate. A similar idea occasionally enables the inferior side to save a draw in the ending of bishop, knight, and king versus lone king.

At left is a remarkable composition by A.J. Roycroft. White draws with 1.c7! Ka1 (if 1...g5 2.c8(R)!! Ng6 3.Rc1+ forces Black to capture, stalemating White) 2.c8(R)!! g5 (2...b1(Q) 3.Rc2!!, and now 3...Qxc2 or 3...g5 is stalemate, while otherwise White will sacrifice his rook on a2) 3.Rc2!! (not 3.Rc1+?? b1(Q)+! 4.Rxb1+ Bxb1#; now White threatens 4.Rxb2 and 5.Rxa2+, forcing stalemate or perpetual check) Bc4 (trying to get in a check; 3...b1(Q), 3...b1(B), and 3...Bb1 are all stalemate; 3...Ng6 4.Rc1+!) 4.Rc1+ Ka2 5.Ra1+ Kb3 6.Ra3+ Kc2 7.Rc3+ Kd2 8.Rc2+ (diagram at right). As in Evans-Reshevsky, Black cannot escape the "eternal rook."

[edit] Stalemate in problems

Some chess problems require "White to move and stalemate black in n moves" (rather than the more common "White to move and checkmate black in n moves").

Problemists have also tried to construct the shortest possible game ending in stalemate: Sam Loyd devised one just ten moves long (1.e3 a5 2.Qh5 Ra6 3.Qxa5 h5 4.Qxc7 Rah6 5.h4 f6 6.Qxd7+ Kf7 7.Qxb7 Qd3 8.Qxb8 Qh7 9.Qxc8 Kg6 10.Qe6 -- see diagram at left below). A similar stalemate is reached after 1.d4 c5 2.dc f6 3.Qxd7+ Kf7 4.Qxd8 Bf5 5.Qxb8 h5 6.Qxa8 Rh6 7.Qxb7 a6 8.Qxa6 Bh7 9.h4 Kg6 10.Qe6 (Frederick Rhine). Loyd also demonstrated that stalemate can occur with all the pieces on the board (1.d4 d6 2.Qd2 e5 3.a4 e4 4.Qf4 f5 5.h3 Be7 6.Qh2 Be6 7.Ra3 c5 8.Rg3 Qa5+ 9.Nd2 Bh4 10.f3 Bb3 11.d5 e3 12.c4 f4 -- see diagram at right below).

[edit] Double stalemate

There are peculiar chess compositions featuring double stalemate. At left and at right are double stalemate positions, in which neither side has a legal move. Such positions are not seen in practical play. There is also a bizarre chess variant, Patt-schach, that begins from a double stalemate position.

[edit] History of the stalemate rule

The stalemate rule has a somewhat convoluted history. In the forerunners to modern chess, such as shatranj, stalemate was a win for the side administering it, and this rule persisted for a while in chess, although when playing for money, a win by stalemate sometimes only won half the stake. According to H. J. R. Murray's A History of Chess (Oxford University Press, 1913), the rule for a time in England was that stalemate was a loss for the player administering it. The modern rule that stalemate is a draw became universally adopted only in the 19th century.

Assume that Black's king is stalemated. Throughout history, a stalemate has at various times been (Davidson 1949:65-66):

• A win for White (10th century Arabia)
• A half-win for White (18th century Spain)
• A win for Black (17th century Russia and in Great Britain into the 19th century)
• Not allowed. If White made a move that would stalemate Black, he had to retract it and make a different move (Eastern Asia until the early 20th century)
• The forfeiture of Black's turn to move (medieval France)
• A draw (started in 14th century Italy and spread through Europe, not adopted in England until the 19th century)

There have been calls to make a stalemate a win for the side causing the stalemate. The effect of such a rule would be a greater emphasis on the material on the board. An extra pawn would be a much greater advantage than it is today, e.g. king and pawn versus king would always be a win unless the defending king were able to capture the pawn. (See the next section.)

[edit] Effect of stalemate on endgames

If stalemate were a loss for the player unable to move, then some endgames would be affected ^[1].

• The endgame of king and pawn versus king would be a win unless the pawn can be captured.

• Two knights and a king can stalemate a king, so that ending would no longer be a draw (see Two knights endgame).

• The drawing techniques with a bishop pawn or rook pawn on the seventh rank with its king nearby versus a queen would not work, because they involve stalemate. See Queen versus pawn.

• A rook pawn plus a bishop on the color opposite the pawn's queening square would be a win instead of a draw.

• A king and rook versus a king and bishop would be a win for the side with the rook (but not rook versus knight).

• Stalemate positions are possible with a king and lone bishop or lone knight against a king.

[edit] See also

• Chess terminology
• checkmate
• draw (chess)
• Swindle (chess)

[edit] Notes

1. ^ http://www.michess.org/webzine_199907/okeefe.shtml

[edit] References

•   Davidson, Henry (1949, 1981). A Short History of Chess. McKay. ISBN 0-679-14550-8.

•   Fischer, Bobby (1969). My 60 Memorable Games. Simon and Schuster.

[edit] External links

• Jack O'Keefe: Stalemate!
• complete score of Pilnick-Reshevsky (scroll down to 12th comment, by "Resignation Trap") -- but note that Black's 26th move should be ...Rc7, not ...c7
• Evans-Reshevsky