Shogi

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Shogi (将棋 shōgi) is one of a family of strategic board games of which chess and xiangqi are also members, which derive from the 6th century Indian game of chaturanga or a close relative thereof. Shogi is native to Japan and is sometimes called Japanese chess.

File:Shogi.png
Shogi, Japanese chess

Rules of the game

Objective

The objective is to checkmate your opponent's king.

Game equipment

Two players, Black and White (or sente and gote), play on a board composed of squares in a grid of 9 ranks (rows) by 9 files (columns). The squares are undifferentiated by marking or colour.

Each player has a set of 20 wedge-shaped pieces, of slightly different sizes. From largest to smallest (most to least powerful) they are:

  • 1 king
  • 1 rook
  • 1 bishop
  • 2 gold generals
  • 2 silver generals
  • 2 knights
  • 2 lances
  • 9 pawns

Most of these names are chosen to correspond to their rough equivalents in Western chess and not as literal translations of the Japanese names.

Each piece has its name marked on its surface in the form of two kanji, usually in black ink. On the reverse side of each piece, other than the king and gold general, are one or two other characters, often in a different colour (usually red); this reverse side is used to indicate that the piece has been promoted during play. The pieces of the two players do not differ in colour, but instead each piece is shaped like a wedge, and faces forward, toward the opposing side. This shows who controls the piece during play. See Shogi Pieces and Symbols for pictures of the pieces, both normal and promoted.

The Chinese characters (kanji) have deterred many people who are not familiar with them from learning shogi. This has led to the development of "Westernized" (or "international") pieces, which replace the characters with intuitive symbols. However, partially because the traditional pieces are iconic by size, with more powerful pieces being larger, most players soon learn to recognize them, and Westernized pieces have never become popular.

Here is a table of the pieces with their Japanese representation. The abbreviations are used both for game notation and in several cases, to refer to the pieces in speech.

Piece Kanji Rōmaji Unicode Hiragana Abbr. Meaning
Black king 玉将 gyokushō 7389 5c06 ぎょくしょう 玉 (gyoku) jade general
White king 王将 ōshō 738b 5c06 おうしょう 王 (ō) royal general
Rook 飛車 hisha 98db 8eca ひしゃ 飛 (hi) flying chariot
Promoted rook 龍王 ryūō 7adc 738b りゅうおう 龍 or 竜* (ryū) dragon king
Bishop 角行 kakugyō 89d2 884c かくぎょう 角 (kaku) angle mover
Promoted bishop 龍馬 ryūma 7adc 99ac りゅうま 馬 (uma) dragon horse
Gold general 金将 kinshō 91d1 5c06 きんしょう 金 (kin) gold general
Silver general 銀将 ginshō 9280 5c06 ぎんしょう 銀 (gin) silver general
Promoted silver 成銀 narigin 6210 9280 なりぎん promoted silver
Knight 桂馬 keima 6842 99ac けいま 桂 (kei) laureled horse
Promoted knight 成桂 narikei 6210 6842 なりけい promoted laurel
Lance 香車 kyōsha 9999 8eca きょうしゃ 香 (kyō) incense chariot
Promoted lance 成香 narikyō 6210 9999 なりきょう promoted incense
Pawn 歩兵 fuhyō 6b69 5175 ふひょう 歩 (fu) foot soldier
Promoted pawn と金 tokin 3068 91d1 ときん と (to) reaches gold

* 竜 is a simplified form of 龍.

English speakers sometimes refer to promoted bishops as horses and promoted rooks as dragons, after their Japanese names, and generally use the Japanese name tokin for promoted pawns. Silver generals and gold generals are commonly referred to simply as silvers and golds.

The characters inscribed on the reverse sides of the pieces to indicate promoted rank may be in red ink, and are usually cursive. The characters on the backs of the pieces that promote to gold generals are cursive versions of 金 'gold', becoming more cursive (more abbreviated) as the value of the original piece decreases. The cursive characters have these equivalents in print: 全 for promoted silver, 今 for promoted knight, 仝 for promoted lance, and 个 for promoted pawn (tokin). Another convention has abbreviated versions of the unpromoted ranks, with a reduced number of strokes: 圭 for promoted knight, 杏 for promoted lance, the same 全 as above for promoted silver, and と for tokin.

Rankings

[1]

Setup

File:Shogi setup.png
The starting setup of a game of shogi, from the perspective of Black.

Each player places his pieces in the positions shown below, pointing toward the opponent.

  • In the rank nearest the player:
    • The king is placed in the center file.
    • The two gold generals are placed in the adjacent files to the king.
    • The two silver generals are placed adjacent to each gold general.
    • The two knights are placed adjacent to each silver general.
    • The two lances are placed in the corners, adjacent to each knight.

That is, the first rank is Template:Overline.

  • In the second rank, each player places:
    • The bishop on the player's left in the same file as the knight.
    • The rook on the player's right in the same file as the knight.
  • In the third rank, the nine pawns are placed one to each file.

Traditionally, even the order of placing the pieces on the board is determined. There are two recognized orders, ohashi and ito. Shogi Pineapple indicates the order (page is in Japanese); ohashi is depicted on the left and ito on the right.

Gameplay

The players alternate taking turns, with Black playing first. (The traditional terms 'black' and 'white' are used to differentiate the sides during discussion of the game, but no longer refer to the colors of the pieces.) A 'play' may be one of two things: A 'move', where a player slides a piece across the board and potentially promotes; or a 'drop', where a captured piece is placed onto an empty square of the board. Each of these options is detailed below.

Professional games are played with a timer, as they are in International Chess.

Movement and capture

Each piece moves in a distinct manner. The king, generals, and pawns move a single square at a time. If an opponent's piece occupies a possible destination, it may be captured by sliding the moving piece to that square and removing the opposing piece from the board. If a friendly piece (that is, a piece controlled by the moving player) occupies the square, the player may not move in that direction.

The knight jumps, that is, it passes over any intervening piece, whether friend or foe, without any effect on either. It is the only piece that can do this.

The lance, bishop, and rook can potentially move any number of squares along a straight line limited by the edge of the board. If an opponent's piece intervenes, it may be captured by moving to that square, and removing it from the board. If a friendly piece intervenes, the moving piece is limited to a distance that stops short of the intervening piece; if the friendly piece is adjacent, it may not move in that direction at all.

Pieces move either orthogonally (that is, forward, backward, or to the side, in the direction of one of the arms of a plus sign, +), or diagonally (in the direction of one of the arms of a multiplication sign, ×). The knight is the only exception.

King

A king can move one square in any direction, orthogonal or diagonal.

Gold general

A gold general can move one square orthogonally, or one square diagonally forward, giving it six possible destinations. It cannot move diagonally backward.

Silver general

A silver general can move one square diagonally or one square directly forward, giving it five possibilities.

Because an unpromoted silver can retreat more easily than a promoted one (see below), it is very common to leave a silver unpromoted at the far side of the board.

Knight

A knight jumps at an angle intermediate between orthogonal and diagonal, amounting to one square forward plus one square diagonally forward, in a single motion. That is, it has a choice of two forward destinations. It cannot move to the sides or backwards.

The knight is the only piece that ignores intervening pieces on the way to its destination, though its destination square must of course be either empty, or occupied by an opponent's piece (in which case the opponent's piece is captured), just as with any other moving piece.

It is often useful to leave a knight unpromoted (see below) at the far side of the board. However, since a knight cannot move backward or to the sides, it must promote when it lands on one of the two farthest ranks and would otherwise be unable to move further.

Lance

A lance can move any number of free squares directly forward. It cannot move backward or to the sides.

It is often useful to leave a lance unpromoted (see below) at the far side of the board. However, since a lance cannot move backward or to the sides, it must promote if it arrives at the farthest rank.

Bishop

A bishop can move any number of free squares along any one of the four diagonal directions.

Because it cannot move orthogonally, an unpromoted bishop can only reach half the squares on the board.

Rook

A rook can move any number of free squares along any one of the four orthogonal directions.

Pawn

A pawn can move one square directly forward. It cannot retreat.

Since a pawn cannot move backward or to the sides, it must promote (see below) if it arrives at the farthest rank. However, in practice, a pawn is promoted whenever possible.

There are two restrictive rules for where a pawn may be dropped (see below).

Promotion

A player's promotion zone is the three farthest ranks, at the original line of the opponent's pawns and beyond — that is, the opponent's territory at setup. If a piece moves across the board at all within the promotion zone, including moves into, out of, or wholly within the zone, but not including drops (see below), then that player may choose to promote the piece at the end of the turn. Promotion is indicated by turning the piece over after it moves, revealing the character for the promoted piece.

Promoting a piece has the effect of changing how that piece moves. Each piece promotes as follows:

  • A king or a gold general cannot promote, nor can pieces which are already promoted.
  • A silver general, knight, lance, or pawn, when promoted, loses its normal movement and gains the movement of a gold general.
  • A bishop or rook, when promoted, keeps its normal movement and gains the ability to move one square in any direction, like a king. This means a promoted bishop is able to reach any square on the board, given enough moves.

If a pawn, knight, or lance reaches the furthest rank, it must be promoted, since it would otherwise have no legal move on subsequent turns. For the same reason, a knight reaching the penultimate rank must be promoted.

When captured, pieces lose their promoted status. Otherwise, promotion becomes permanent.

Drops

Captured pieces are truly captured in shogi. They are retained "in hand", and can be brought back into play under the capturing player's control. On any turn, instead of moving a piece, a player can take a piece that was previously captured and place it, unpromoted side up, on any empty square, facing the opponent. The piece is now part of the forces controlled by that player. This is termed dropping the piece, or just a drop.

A drop cannot capture a piece, nor does dropping within the promotion zone result in immediate promotion. However, either capture or promotion may occur normally on subsequent moves by the piece.

A pawn, knight, or lance may not be dropped on the furthest rank, since it would have no legal move on subsequent turns. Similarly, a knight may not be dropped on the penultimate rank.

There are two other restrictions when dropping pawns:

A pawn cannot be dropped onto the same file (column) as another unpromoted pawn controlled by the same player. (A tokin does not count as a pawn here.) A player who has an unpromoted pawn on every file is therefore unable to drop a pawn anywhere. For this reason, it is common to sacrifice a pawn in order to gain flexibility for drops.

A pawn cannot be dropped to give an immediate checkmate. Other pieces may be dropped to give immediate checkmate, however. A pawn that is already on the board may be advanced to give checkmate as well, and a pawn may be dropped where either it or another piece can mate on a subsequent turn.

It is very common for players to swap bishops, which face each other across the board. This leaves each player with a bishop "in hand" to be dropped later, and gives an advantage to the player with the stronger defensive position.

Check and mate

When a player makes a move such that the opponent's king could be captured on the following move, the move is said to give check to the king; the king is said to be in check. If a player's king is in check and no legal move by that player will get the king out of check, the checking move is also a mate, and effectively wins the game.

To say "check!" in Japanese, one says "ōte!" (王手). This is perhaps an influence of Western chess, and is not required. Checkmate is called tsume (詰め) or ōtedzume (王手詰め).

Game end

A player who captures the opponent's king wins the game. In practice this rarely happens, as a player will resign when loss is inevitable (as in International Chess).

If a player is not in check, but can make no legal move, then the game is a loss for that player. (It would be stalemate in International Chess).

In professional games, a player who makes an illegal move loses immediately. This includes violating the restrictions on pawn drops.

There are two other possible, if uncommon, ways for a game to end: repetition (千日手 sennichite) and impasse (持将棋 jishōgi).

If the same game position occurs four times with the same player to play, then the game is no contest. For two positions to be considered the same, the pieces in hand must be the same, as well as the position on the board.

The game reaches an impasse if both kings have advanced into their respective promotion zones and neither player can hope to mate the other or to gain any further material. If this happens then the winner is decided as follows: each rook or bishop scores 5 points for the owning player, and all other pieces except kings score 1 point each. (Promotions are ignored for the purposes of scoring.) A player scoring less than 24 points loses. If both players have at least 24 points, then the game is no contest.

Games which are no contest are usually counted as draws in amateur tournaments, but in professional tournaments the rules typically require the game to be replayed with colours reversed (possibly with reduced time limits).

Handicaps

Games between players of disparate strength are often played with handicaps. In a handicap game, one or more of White's pieces are removed before the start of play and White plays the first move of the game. Note that the pieces removed at the beginning of play have no further part in the game: They are not available for drops. The imbalance created by this method of handicapping is not as strong as it is in chess, because material advantage is not as powerful in shogi as in chess.

Common handicaps, in increasing order of size, are as follows:

  • Lance: remove White's left lance
  • Bishop: remove White's bishop
  • Rook: remove White's rook
  • Rook and lance: remove White's rook and left lance
  • Two pieces: remove White's rook and bishop
  • Four pieces: remove White's rook, bishop and both lances
  • Six pieces: remove White's rook, bishop, both lances and both knights

Other handicaps are also occasionally used. The relationship between handicaps and differences in rank is not universally agreed upon; several different systems are in use.

Game notation

The method used in English-language texts to express shogi moves was established by George Hodges in 1976. It is derived from the algebraic notation used for chess, but differs in several respects.

A typical example is P-8f. The first letter represents the piece moved: P = pawn, L = lance, N = knight, S = silver, G = gold, B = bishop, R = rook, K = king. Promoted pieces have a + added in front of the letter. e.g., +P for a tokin (promoted pawn). The designation of the piece is followed by a symbol indicating the type of move: - for an ordinary move, x for a capture, or * for a drop. Next is the designation for the square on which the piece lands. This consists of a number representing the file and a lowercase letter representing the rank, with 1a being the top right corner (as seen from Black's point of view) and 9i being the bottom left corner. (This method of designating squares is based on Japanese convention, which, however, uses Japanese numerals instead of letters. For example, the square 2c is denoted by 2三 in Japanese.)

If a move entitles the player to promote the piece, then a + is added to the end to signify that the promotion was taken, or an = to indicate that it was declined. For example, Nx7c= indicates a knight capturing on 7c without promoting.

In cases where this would be ambiguous, the starting square is added to the letter for the piece. For example, in the initial position Black has two golds which can be moved to square 5h in front of the king, and these are distinguished as G6i-5h (from the left) and G4i-5h (from the right).

Moves are commonly numbered as in chess. For example, the start of a game might look like this:

    1. P-7f   P-3d
    2. P-2f   G-3b
    3. P-2e   Bx8h+
    4. Sx8h   S-2b

In handicap games White plays first, so Black's move 1 is replaced by an ellipsis.

Strategy and tactics

Drops are the most serious departure from International Chess. They entail a different strategy, with a strong defensive position being much more important. A quick offense will leave a player's home territory open to drop attacks as soon as pieces are exchanged. Because pawns attack head on, and cannot defend each other, they tend to be lost early in the game, providing ammunition for such attacks. Dropping a pawn behind enemy lines, promoting, and dropping a second pawn immediately behind so that they protect each other makes a strong attack; it threatens the opponent's entire defense, but provides little of value if the attack fails and the pieces are captured.

Players raised on International Chess often make poor use of drops, but dropping is half the game. If a player has more than a couple captured pieces in hand, it is likely that dropping attacks are being overlooked. However, it is wise to keep a pawn in hand, and often to exchange pieces if necessary to get one.

A decision made early in the game will be whether or not to exchange bishops. If exchanged, it may be possible to drop a bishop behind poorly defended enemy territory for a "fork" attack, threatening two vital pieces at once. (Silvers are also commonly used this way.) Even if such a bishop merely retreats, it may promote in doing so, and a promoted bishop can dominate the board.

However, attacking pieces can easily become trapped behind enemy lines, as the opponent can often drop a pawn on a protected square to cut off the line of retreat. For this reason, rooks are commonly kept at a safe distance in the early parts of the game, and used instead to support attacks by weaker pieces.

Many common attacks involve advancing a silver along a file protected by the rook. Because silvers have more possibilities for retreat, while golds protect pieces at their sides, silvers are generally considered superior as attacking pieces, and golds superior as defensive pieces.

There are various ranging rook openings, where the rook moves to the center or left of the board to support an attack. However, as the most powerful piece on the board, it invites attack, and may be a good idea to keep your king well away from your rook.

Advancing a lance pawn can open up the side of the board for attack. Therefore, when a player first advances a lance pawn, it is usual for the opponent to answer by advancing the opposing pawn, in order to avoid complications later in the game.

Because defense is so important, and because shogi pieces are relatively slow movers, the opening game tends to be much longer than in Western chess, with a dozen or so moves to shore up defenses before any attack is made.

The Yagura castle

File:Shogi Yagura defense.png
The Yagura defensive opening

The Yagura castle is considered by many to be the strongest starting position in shogi. It has a strongly protected king; a well fortified line of pawns; and the bishop, rook, and a pawn all support a later attack by the rook's silver or knight. However, one's opponent may just as easily castle this way, giving neither side an advantage.

Instead of the rook's pawn being advanced two squares as shown here, the pawn on the third file is often advanced one square, allowing both the rook's silver and knight to move forward. These offensive moves are not properly part of the castle defence, but the two-square pawn advance must be carried out early, if there is to be room for it, and so it is often done while still castling.

There is a good deal of flexibility in the order of moves when building the Yagura defense, and they are not listed here. The only point to keep in mind is that the generals should move diagonally, not directly forward. However, a strong intermediate position, called kani ("crab"), has the three pawns on the left side advanced to their final Yagura positions; and on the second rank, all four generals are lined up next to the bishop, which is still in its starting position: Template:Overline. The king is moved one square to the left, behind the middle silver.

A common attack against a Yagura defense is to advance the rook's knight directly forward, with a pawn in hand, to attack the fortifications on either side of the king. If the defender has answered a lance's pawn advance on that side, a pawn may be dropped where the edge pawn had been. If the defending silver has moved or is not yet in position, a pawn may be dropped there.

Shogi books in English

  • Shogi for Beginners (1984) by John Fairbairn
  • Guide to Shogi openings: Shogi problems in Japanese and English (1983) by Aono Teruichi, translated by John Fairbairn
  • Better Moves for Better Shogi (1983) by Aono Teruichi, translated by John Fairbairn
  • The Art of Shogi (1997) by Tony Hosking
  • Habu's Words (2000) by Habu Yoshiharu, translated by Takahashi Yamato and Tony Hosking

See also

External links

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