Rook (chess)

Rook in the standard Staunton pattern.

A rook, (♖ ♜, borrowed from Persian رخ rokh, Sanskrit rath, "chariot") also known as a castle, is a piece in the strategy board game of chess. Each player starts with two rooks, one in each of the corners nearest their own side. Although the piece was widely known as the castle in 17th and 18th century England, (Sunnucks 1970) this term is no longer used by chess players (Hooper & Whyld 1992).

Initial placement and movement

In algebraic notation, the white rooks start on a1 and h1, while the black rooks start on a8 and h8. The rook moves horizontally or vertically, forward or back, through any number of unoccupied squares, as shown in the diagram. Like other pieces, it captures by occupying the square on which an enemy piece stands. The rook also participates, along with the king, in a special move called castling.

Starting location of the rooks The white rook may move to any square with a white dot. The black rook may move to any square marked with a black dot or capture the white pawn. Chess pieces King Queen Rook Bishop Knight Pawn

History

Originally, the rook symbolized a chariot. The Persian word rokh means chariot, and the corresponding pieces in Oriental chess games such as xiangqi and shogi have names meaning chariot. Persian War Chariots were heavily armoured, carrying a driver and at least one ranged-weapon bearer, such as an archer. The sides of the chariot were built to resemble fortified stone work, giving the impression of small, mobile buildings, causing terror on the battlefield. However, in the West, the rook is almost universally represented as a crenellated turret. One possible explanation is that when the game was imported to Italy, the Persian rokh became the Italian word rocca, meaning fortress. Another possible explanation is that rooks represent siege towers. Rooks usually are similar in appearance to small castles, and as a result, a rook is sometimes called a "castle", usually by non-players and those new to the game. This usage was common in the past ("The Rook, or Castle, is next in power to the Queen" —Howard Staunton, 1847) but today it is rarely, if ever, used in the literature or among players, except in reference to castling. (Here, "castle" is a verb referring to a move, not a noun referring to a piece.)

Strategy

In general, rooks are stronger than bishops or knights and are consequently considered about two pawns greater in value. Winning a rook for a bishop or knight is referred to as winning the exchange. Two rooks are generally considered to be worth slightly more than a queen (see Chess piece point value). Rooks and queens are called heavy pieces or major pieces, as opposed to bishops and knights, which are called minor pieces.

Polugaevsky-Evans, 1970

White to move, draws.

In the opening, the rooks are undefended by other pieces, so it is usually desirable to connect one's rooks on the first rank by castling and clearing all pieces except the king and rooks from the first rank. In that position, the rooks protect each other, and can easily move to threaten the most favorable files.

A common goal with a rook is to place it on the first rank of an open file, i.e. one unobstructed by pawns of either player, or a half-open file, i.e. one unobstructed by friendly pawns. From this position, the rook is relatively unexposed to risk but can control every square on the file. If one file is particularly important, a player may advance one rook on it, and move the other behind, doubling the rooks.

A rook on the seventh rank (the opponent's second rank) is usually very powerful, as it threatens the opponent's unadvanced pawns and hems in the enemy king. A rook on the seventh rank is sufficient compensation for a pawn (Fine & Benko 2003:586). In this position between Lev Polugaevsky and Larry Evans, the rook on the seventh rank enables White to draw, despite being a pawn down (Griffiths 1992:102-3).

Two rooks on the seventh rank are often enough to force victory, or at least a draw by perpetual check. These rooks are sometimes colloquially referred to as "pigs on the seventh", because they often threaten to "eat" the opponent's pieces or pawns.

Rooks are most powerful towards the end of a game, where they can move unobstructed by pawns and control large numbers of squares. They are somewhat clumsy at restraining enemy pawns from advancing towards promotion, unless they can occupy the file behind the advancing pawn. By the same token, a rook best supports a friendly pawn towards promotion from behind it in the same file.

A rook is a very powerful piece to deliver a checkmate. Below follows a few examples of rook checkmates that are easy to force.

A two rook checkmate

A king and rook checkmate. The same constellation is used to force the enemy king to move towards the edge of the board.

A back rank checkmate. This situation frequently occur, mostly as a threat. The white rook and the knight can only delay the inevitable.

Symbology

In heraldry, chess rooks are often used as charges. Unlike a real chess rook, they are conventionally shown with two outward-curving horns. This is because they would otherwise appear to be castle towers, since there is no proportion on a coat of arms. This charge is always blazoned "chess rook" so as not to be confused with the bird of that name; it is also not to be confused with the zule, a similar-looking object with two outward-curving horns at both top and bottom.

In Canadian heraldry, the chess rook is the brisure of the fifth daughter.

See also

• Tarrasch rule
• Rook and pawn versus rook endgame
• Lucena position
• Philidor position
• Staunton chess set
• Chess piece point value

References

• Brace, Edward R. (1977), An Illustrated Dictionary of Chess, Hamlyn Publishing Group, pp. 241,242, ISBN 1-55521-394-4 

• Barden, Leonard (1980), Play Better Chess with Leonard Barden, Octopus Books Limited, p. 10, ISBN 0-7064-0967-1 

• Fine, Reuben; Benko, Pal (2003), Basic Chess Endings (1941) (second ed.), McKay, ISBN 0-8129-3493-8 

• Griffiths, Peter (1992), Exploring the Endgame, American Chess Promotions, ISBN 0-939298-83-X 

• Hooper, David; Whyld, Kenneth (1992), The Oxford Companion to Chess (second ed.), Oxford University Press, ISBN 0-19-280049-3 

• Sunnucks, Anne (1970), The Encyclopaedia of Chess, St. Martins Press, ISBN 978-0709146971