| 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 | ||
A Grimshaw is a device found in chess problems in which two pieces (usually a rook and bishop) arriving on a particular square mutually interfere with each other. It is named after the 19th-century problem composer Walter Grimshaw. The Grimshaw is one of the most common devices found in directmates.
The theme can be understood by reference to the displayed example by A. G. Corrias (published in Good Companion, 1917).
The problem is a mate in two (White must move first and checkmate Black in two moves against any defense). The key is 1.Qb1, which threatens 2.Qb7#. Black has three ways to defend against this.
It is the other two black defenses, however, which show the Grimshaw theme.
It is this mutual interference between two black pieces on the one square (in this case, a rook and a bishop on b2) that constitutes a Grimshaw.
| 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 | ||
The key in the puzzle on the right is 1. Qd2. This move has no threat, but it leaves black in zugzwang: Black must either move one of his bishops or rooks, or move a pawn. However, any bishop or rook move must unguard one of the squares of d5, d6, d7 or d8, allowing White to mate on d5, d6 or d7 with the queen, and d8 with the knight. The lines are:
The pieces involved in Grimshaws are usually rook and bishop, as in the previous example, although Grimshaws involving pawns are also seen, as in this mate in two example by Frank Janet (published in the St.Louis Globe Democrat, 1916):
| 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 | ||
The key is 1.Qd7, threatening 2.Qf5#. As in the previous example, Black can defend by cutting White's queen off from its intended destination square, but two of these defences have fatal flaws in that they interfere with other pieces: 1...Be6 interferes with the pawn on e7, allowing 2.Qxc7# (2...e5 would be possible were the bishop not on e6) and 1...e6 interferes with the bishop, allowing 2.Qxa4# (2...Bc4 would be possible were the pawn not on e6). It is this mutual interference between bishop and pawn on e6 which constitutes the pawn Grimshaw. There are several other non-thematic black defences in this problem — see below for them all.
Sometimes, multiple Grimshaws can be combined in one problem. Here are two examples by Lev Ilych Loshinsky each with three Grimshaws.
| 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 | ||
This was first published in L'Italia Scacchistica, 1930. It is a mate in two. The key is 1.Rb1, with the threat 2.d4#. Each of Black's defences produces a Grimshaw interference which stops him from capturing White's mating piece. Black's defences, with White's replies, are:
There is one other black defence: 1...Rd6 leading to the simple recapture 2.Bxd6# (this is essentially the same mate as that which follows 1...Be6).
| 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 | ||
This second Loshinsky example, also a mate in two, is from Tijdschrift v.d. Nederlandse Schaakbond, 1930, and is one of the most famous of all chess problems. It is a complete block (if White could pass his first move, then he could reply to every black move with a mate), and White's key, 1.Bb3, holds this block, making no threat, but putting Black in zugzwang. Black has six defences leading to three Grimshaws, one of them a pawn Grimshaw:
After other black moves, White can play one of the above moves to mate; the three exceptions are 1...f5, taking away that square from the king and allowed 2.Qd6# and two recaptures: 1...Rxc7 2.Nxc7# and 1...Bxd4 2.Nxd4#.
A close relative of the Grimshaw is the Novotny, which is essentially a Grimshaw brought about by a white sacrifice on a square where it can be captured by two different black pieces – whichever black piece captures the white piece, it interferes with the other.
A chess problem, also called a chess composition, is a puzzle set by the composer using chess pieces on a chess board, which presents the solver with a particular task. For instance, a position may be given with the instruction that White is to move first, and checkmate Black in two moves against any possible defence. A chess problem fundamentally differs from over-the-board play in that the latter involves a struggle between Black and White, whereas the former involves a competition between the composer and the solver. Most positions which occur in a chess problem are unrealistic in the sense that they are very unlikely to occur in over-the-board play. There is a good deal of specialized jargon used in connection with chess problems.
Walter Grimshaw was a 19th-century British composer of chess problems. In 1854 he won the first ever chess problem composition tourney in London. He is perhaps best known for giving his name to the Grimshaw, a popular problem theme.
The Novotny is a device found in chess problems named after a problem from 1854 by Antonín Novotný, though the first example was composed by Henry Turton in 1851. A piece is sacrificed on a square where it could be taken by two different opposing pieces, but whichever makes the capture, it interferes with the other. It is essentially a Grimshaw brought about by a sacrifice on the critical square.
The Evergreen Game is a famous chess game won by Adolf Anderssen against Jean Dufresne in 1852.
The Opera Game was a chess game played in 1858 at an opera house in Paris. The American master Paul Morphy played against two amateurs: the German noble Karl II, Duke of Brunswick, and the French aristocrat Comte Isouard de Vauvenargues. It was played as a consultation game, with Duke Karl and Count Isouard jointly deciding each move for the black pieces, while Morphy controlled the white pieces by himself. The game was played in a box while an opera was performed on stage. Morphy quickly checkmated his opponents following rapid development and sacrifice of material, including a queen sacrifice.
In chess, fool's mate is the checkmate delivered after the fewest possible moves from the game's starting position. It arises from the following moves, or similar:
The Giuoco Piano is a chess opening beginning with the moves:
In the game of chess, interference occurs when the line between an attacked piece and its defender is interrupted by sacrificially interposing a piece. It is a chess tactic which seldom arises, and is therefore often overlooked. Opportunities for interference are rare because the defended object must be more valuable than the sacrificed piece, and the interposition must itself present a threat. Huczek defines interference as a tactic involving blocking moves that obstruct lines of attack. This definition may be expanded by including blocking moves that disrupt lines of defense.
The Budapest Gambit is a chess opening that begins with the moves:
The World Chess Championship 2006 was a match between Classical World Chess Champion Vladimir Kramnik and FIDE World Chess Champion Veselin Topalov. The title of World Chess Champion had been split for 13 years. This match, played between September 23 and October 13, 2006, in Elista, Kalmykia, Russia, was to reunite the two World Chess Champion titles and produce an undisputed World Champion.
The Accelerated Dragon is a chess opening variation of the Sicilian Defence that begins with the moves:
In chess, a swindle is a ruse by which a player in a losing position tricks their opponent and thereby achieves a win or draw instead of the expected loss. It may also refer more generally to obtaining a win or draw from a clearly losing position. I. A. Horowitz and Fred Reinfeld distinguish among "traps", "pitfalls", and "swindles". In their terminology, a "trap" refers to a situation where players go wrong through their own efforts. In a "pitfall", the beneficiary of the pitfall plays an active role, creating a situation where a plausible move by the opponent will turn out badly. A "swindle" is a pitfall adopted by a player who has a clearly lost game. Horowitz and Reinfeld observe that swindles, "though ignored in virtually all chess books", "play an enormously important role in over-the-board chess, and decide the fate of countless games".
The World Chess Championship 1886 was the first official World Chess Championship match contested by Wilhelm Steinitz and Johannes Zukertort. The match took place in the United States from 11 January to 29 March, the first five games being played in New York City, the next four being played in St. Louis and the final eleven in New Orleans. The winner was the first player to achieve ten wins. Wilhelm Steinitz won the match 10–5, winning his tenth game in the twentieth game of the match. There were five draws.
The World Chess Championship 1889 was the second official World Chess Championship, and was between Wilhelm Steinitz and Mikhail Chigorin. It took place in Havana, Cuba. Steinitz defended his world title, and was the first of the two players to reach 10½. He won the match 10½-6½.
A reflexmate is a chess problem in which white, moving first, must force black to deliver checkmate within a specified number of moves against their will – with the added condition that if either player can give checkmate, they must. If this condition applies only to Black, it is a semi-reflexmate.
A World Chess Championship was played between challenger Max Euwe and title-holder Alexander Alekhine in various cities and towns in the Netherlands from 3 October to 16 December 1935. Euwe was the winner by overcoming a three-point deficit as late as the ninth game.
The 1978 World Chess Championship was played between Anatoly Karpov and Viktor Korchnoi in Baguio, Philippines, from July 18 to October 18, 1978. Karpov won, thereby retaining the title.
The 1981 World Chess Championship was played between Anatoly Karpov and Viktor Korchnoi in Merano, Italy from October 1 to November 19, 1981. Karpov won with six wins against two, with 10 draws. The two players had already played against each other in the World Chess Championship match 1978 in the Philippines, when Karpov also won.
The World Chess Championship 2014 was a match between the world champion Magnus Carlsen and challenger Viswanathan Anand, to determine the World Chess Champion. It was held from 7 to 25 November 2014, under the auspices of the World Chess Federation (FIDE) in Sochi, Russia.
Levitsky versus Marshall, also known as the Gold Coins Game, is a famous game of chess played by Stepan Levitsky and Frank Marshall. It was played in Breslau on July 20, 1912, during the master's tournament of the DSB Congress. According to legend, after Marshall's winning last move of the game, gold coins were tossed onto the board by spectators, although this is contested by other accounts.