Японские шахматы: Стратегия и правила сёги

Japanese strategy board game

, also known as Japanese chess, is a strategy board game for two players. It is one of the most popular board games in Japan and is in the same family of games as Western chess, chaturanga, xiangqi, Indian chess, and janggi. Shōgi means general's (shō 将) board game (gi 棋). Shogi was the earliest historical chess related game to allow captured pieces to be returned to the board by the capturing player. The earliest predecessor of the game, chaturanga, originated in India in the 6th century, and the game was likely transmitted to Japan via China or Korea sometime after the Nara period. Shogi in its present form was played as early as the 16th century, while a direct ancestor without the drop rule was recorded from 1210 in a historical document Nichūreki, which is an edited copy of Shōchūreki and Kaichūreki from the late Heian period (c. 1120).

The usual goal of a game is for one player to checkmate the other player's king, winning the game.

Captured pieces are retained in hand and can be brought back into play under the capturing player's control. The Japanese term for piece(s) in hand is either 持ち駒 mochigoma or 手駒 tegoma. On any turn, instead of moving a piece on the board, a player may select a piece in hand and place it – unpromoted side up and facing the opposing side – on any empty square. The piece is then one of that player's active pieces on the board and can be moved accordingly. This is called dropping the piece, or simply, a drop. A drop counts as a complete move. A drop cannot capture a piece, nor does dropping within the promotion zone result in immediate promotion. Capture and/or promotion may occur normally, however, on subsequent moves of the piece. Restrictions. There are three restrictions on dropping pieces; the last two of these apply only to pawns. Piece with No Moves ([[:ja:行き所のない駒 ikidokorononaikoma): Pawns, lances and knights may not be dropped onto the last (9th) rank, and knights may not be dropped onto the penultimate (8th) rank; this is because such dropped pieces would have no legal moves on subsequent turns (as they can only move in the forward direction). Two Pawns ([[:ja:二歩 nifu): A pawn may not be dropped onto a file (column) containing another unpromoted pawn of the same player (promoted pawns do not count). Drop Pawn Mate ([[:ja:打ち歩詰め uchifuzume): A pawn may not be dropped to give an immediate checkmate. (This rule only applies specifically to pawns, drops and checkmates − to clarify, a player may deliver an immediate checkmate by dropping a non pawn piece, a player may checkmate a king with a pawn that is already on the board, and a pawn may be dropped to give an immediate check as long as it does not also result in checkmate.) A corollary of the second restriction is that a player with an unpromoted pawn on every file is unable to drop a pawn anywhere. For this reason, it is common to sacrifice a pawn in order to gain flexibility for drops. Captured pieces are typically kept on a wooden stand (駒台 komadai) which is traditionally placed so that its bottom left corner aligns with the bottom right corner of the board from the perspective of each player. It is not permissible to hide pieces from full view. It is common for players to swap bishops, which oppose each other across the board, early in the game. This leaves each player with a bishop in hand to be dropped later. The ability for drops in shogi gives the game tactical richness and complexity. The fact that no piece ever goes entirely out of play accounts for the rarity of draws.

When a player's move threatens to capture the opposing king on the next turn, the move is said to give check to the king and the king is said to be in check. If a player's king is in check, that player's responding move must remove the check. Ways to remove a check include moving the king away from the threat, capturing the threatening piece, or placing another interposing piece between the king and the threatening piece. To announce check in Japanese, one can say ōte (王手), however, this is an influence of international chess and is not required, even as a courtesy. It may be common to announce ōte in beginner matches or for local rules to dictate that you have to announce it. Announcing a check vocally is unheard of in competitive tournaments.

If the king is in check and there is no possible move which could protect the king, the move is said to checkmate (tsumi 詰み) the king. Checkmate effectively means that the opponent wins the game as the player would have no remaining legal moves. The resignation is indicated by bowing and/or saying 'I lost' (負けました makemashita) and/or placing the right hand over the piece stands. Placing the hand over the piece stand is a vestige of an older practice of gently dropping one's pieces in hand over the board in order to indicate resignation. In western practice, a handshake may be used.

If the same game position occurs four times with the same player to move and the same pieces in hand for each player, then the game ends in a repetition draw (千日手 sennichite, lit. "moves for a thousand days"), as long as the positions are not due to perpetual check. Perpetual check (連続王手の千日手) is an illegal move (see above), which ends the game in a loss in tournament play. In professional shogi, a repetition draw outcome is not a final result as draws essentially do not count. Each game can only end in either a win or loss. In the case of a repetition draw, professional shogi players will have to immediately play a subsequent game (or as many games as necessary) with sides reversed in order to obtain a true win outcome. (That is, the player who was White becomes Black, and vice versa.) Also, depending on the tournament, professional players play the subsequent game in the remainder of the allowed game time. Thus, aiming for a repetition draw may be a possible professional strategy for the White player in order to play the second replay game as Black, which has a slight statistical advantage and/or greater initiative. For instance, Bishop Exchange Fourth File Rook is a passive strategy for White with the goal of a repetition draw (as it requires two tempo losses – swinging the rook and trading the bishops) while it is a very aggressive strategy if played by Black. Repetition draws are rare in professional shogi occurring in about 1–2% of games and even rarer in amateur games. In professional shogi, repetition draws usually occur in the opening as certain positions are reached that are theoretically disadvantaged for both sides (reciprocal zugzwang). In amateur shogi, repetition draws tend to occur in the middle or endgame as a result of player errors.

The game reaches an Impasse or Deadlock (持将棋 jishōgi) if both kings have advanced into their respective promotion zones – a situation known as 相入玉 (ai nyū gyoku "double entering kings") – and neither player can hope to mate the other or to gain any further material. An Impasse can result in either a win or a draw. If an Impasse happens, the winner is decided as follows: each player agrees to an Impasse, then each rook or bishop, promoted or not, scores 5 points for the owning player, and all other pieces except kings score 1 point each. A player scoring fewer than 24 points loses. (Note that in the start position, both players have 27 points each.) If neither player has fewer than 24, the game is no contest – a draw. In professional shogi, an Impasse result is always a draw since a player that cannot obtain the 24 points will simply resign. Jishōgi is considered an outcome in its own right rather than no contest, but there is no practical difference. As an Impasse needs to be agreed on for the rule to be invoked, a player may refuse to do so and attempt to win the game in future moves. If that happens, there is no official rule about the verdict of the game. However, in amateur shogi, there are different practices most of which force a win resolution to the Impasse in order to avoid a draw result. The first draw by Impasse occurred in 1731 in a bishop handicap game between the seventh Lifetime Meijin, Sōkan Itō II, and his brother, Sōkei Ōhashi.

As a practical matter, when an opponent's king has entered a player's own territory especially with supporting defending pieces, the opponent's king is often very difficult to mate given the forward attacking nature of most shogi pieces. This state is referred to as entering king (入玉 nyū gyoku). If both players' kings are in entering king states, the game becomes more likely to result in an impasse. In the adjacent diagram example, although White's king is in a strong Bear in the hole castle, Black's king has entered White's territory making it very difficult to mate. Therefore, this position favors Black. An example of Entering King occurred in the fourth game of the 60th Ōi title match between Masayuki Toyoshima and Kazuki Kimura held on August 2021, 2019. After being unsuccessful in attacking Kimura and also in defending his own king within his camp, Toyoshima (playing as White) moved his king away from Kimura's attacking pieces by fleeing up the second file, ultimately entering his king into Kimura's camp by move 150. Although Toyoshima had achieved Entering King, he still had only 23 pointsone point shy of the required 24 points for an Impasse drawwhile Kimura (Black) had 31 points. Toyoshima then spent the next 134 moves trying to bring his point total, which fluctuated between 17 and 23, up to the necessary 24. By the 231st move, the game had reached a Double Entering Kings state, and by move 285 Kimura had successfully kept Toyoshima's point total at bay. Here, Toyoshima with 20 points (and Kimura at 34 points) resigned. Incidentally, this game broke the record of longest game in a title match.

For amateur games, there are various guidances with little standardization. Fairbairn reports a practice in the 1980s (considered a rule by the now defunct Shogi Association for The West) where the dispute is resolved by either player moving all friendly pieces into the promotion zone and then the game ends with points tallied. Another resolution is the 27 Point (27点法) rule used for some amateur tournaments. One version of this is simply the player who has 27 or more points is the winner of the Impasse. Another version is a 27 Point Declaration rule. For instance, the Declaration rule on the online shogi site, 81Dojo, is that the player who wants to declare an Impasse win must (i) declare an intention to win via Impasse, (ii) have the king in the enemy camp (the promotion zone for that player), (iii) 10 other pieces must be in the promotion zone, (iv) not be in check, (v) have time remaining, and (vi) must have 28 points if Black or 27 points if White. If all of these conditions are met, then the Impasse declarer will win the game regardless of whether the opponent objects. Yet another resolution to Impasse is the so called Try Rule (トライルール torairūru). In this case, after both kings have entered their corresponding promotion zones, then the player who first moves the king to the opponent's king's start square (51 for Black, 59 for White) first will be the winner. As an example, the popular 将棋ウォーズ (Shogi Wars) app by HEROZ Inc. used the Try Rule up until 2014. (Now the app uses a variant of the 27 Point Declaration Rule – although it differs from the variant used on the 81Dojo site.) The idea of "Try Rule" was taken from rugby football (see Try (rugby)).

In professional tournaments, the rules typically require drawn games to be replayed with sides reversed, possibly with reduced time limits. They are rare compared to chess and xiangqi, occurring at a rate of 1–2% even in amateur games. The 1982 Meijin title match between Makoto Nakahara and Hifumi Katoh was unusual in this regard with an impasse draw in the first (Double Fortress) game on April 13–14 (only the fifth draw in the then 40 year history of the tournament). This game (with Katoh as Black) lasted for 223 moves with 114 minutes spent pondering a single move. One of the reasons for the length of this game was that White (Nakahara) was very close to falling below the minimum of 24 points required for a draw. Thus, the end of the endgame was strategically about trying to keep White's points above the 24 point threshold. In this match, sennichite occurred in the sixth and eighth games. Thus, this best of seven match lasted eight games and took over three months to finish; Black did not lose a single game and the eventual victor was Katoh at 4–3.

Professional games are timed as in international chess, but professional shogi players are almost never expected to keep time in their games. Instead a timekeeper is assigned, typically an apprentice professional. Time limits are much longer than in international chess (9 hours a side plus extra time in the prestigious Meijin title match), and in addition byōyomi (literally "second counting") is employed. This means that when the ordinary time has run out, the player will from that point on have a certain amount of time to complete every move (a byōyomi period), typically upwards of one minute. The final ten seconds are counted down, and if the time expires the player to move loses the game immediately. Amateurs often play with electronic clocks that beep out the final ten seconds of a byōyomi period, with a prolonged beep for the last five.

Amateur players are ranked from 15 kyū to 1 kyū and then from 1 dan to 8 dan. Amateur 8 dan was previously only honorarily given to famous people. While it is now possible to win amateur 8 dan by actual strength (winning amateur Ryu oh 3 times), this has yet to be achieved. Professional players operate with their own scale, from 6 kyū to 3 dan for pro aspiring players and professional 4 dan to 9 dan for formal professional players. Amateur and professional ranks are offset (with amateur 4 dan being equivalent to professional 6 kyū).

Shogi has a handicap system (like go) in which games between players of disparate strengths are adjusted so that the stronger player is put in a more disadvantageous position in order to compensate for the difference in playing levels. In a handicap game, one or more of White's pieces are removed from the setup, and instead White plays first.

There are two common systems used to notate piece movements in shogi game records. One is used in Japanese language texts while a second was created for western players by George Hodges and Glyndon Townhill in the English language. This system was updated by Hosking to be closer to the Japanese standard (two numerals). Other systems are used to notate shogi board positions. Unlike chess, the origin (11 square) is at the top right of a printed position rather than the bottom left. In western piece movement notation, the format is the piece initial followed by the type of movement and finally the file and rank where the piece moved to. The piece initials are K (King), R (Rook), B (Bishop), G (Gold), S (Silver), N (Knight), L (Lance), and P (Pawn). Simple movement is indicated with , captures with x, and piece drops with *. The files are indicated with numerals 1–9. The older Hodges standard used letters a–i for ranks, and the newer Hosking standard also uses numerals 1–9 for the ranks. Thus, Rx24 indicates 'rook captures on 24'. Promoted pieces are notated with + prefixed to the piece initial (e. g. +Rx24). Piece promotion is also indicated with + (e. g. S 21+) while unpromotion is indicated with = (e. g. S 21=). Piece ambiguity is resolved by notating which square a piece is moving from (e. g. N65 53+ means 'knight from 65 moves to 53 and promotes,' which distinguishes it from N45 53+). The Japanese notation system uses Japanese characters for pieces and promotion indication and uses Japanese numerals instead of letters for ranks. Movement type aside from drops is not indicated, and the conventions for resolving ambiguity are quite different from the western system. As examples, the western Rx24 would be 2四飛 in Japanese notation, +Rx24 would be 2四龍, S 21+ would be 2一銀成, S 21= would be 2一銀不成, and N65 53+ would be 5三桂左成 showing that the leftmost knight jumped (implicitly from the 65 square), which distinguishes it from 5三桂右成 in which the rightmost knight jumped. Although not strictly part of the notational calculus for games, game results are indicated in Japanese newspapers, websites, etc. with wins indicated by a white circle and losses indicated by a black circle.

Shogi is similar to chess but has a much larger game tree complexity because of the use of drops, greater number of pieces, and larger board size. In comparison, shogi games average about 140 (half )moves per game (or 70 chess move pairs) whereas chess games average about 80 moves per game (or 40 chess move pairs) and minishogi averages about 40 moves per game (or 20 chess move pairs). Like chess, however, the game can be divided into the opening, middle game and endgame, each requiring a different strategy. The opening consists of arranging one's defenses usually in a castle and positioning for attack; the mid game consists of attempting to break through the opposing defenses while maintaining one's own; and the endgame starts when one side's defenses have been compromised. In the adjacent diagram, Black has chosen a Ranging Rook position (specifically Fourth File Rook) where the rook has been moved leftward away from its starting position. Additionally, Black is utilizing a Silver Crown castle, which is a type of fortification structure constructed with one silver and two gold pieces and the king moved inside of the fortification – the silver crown name comes from the silver being positioned directly above the king's head on the 27 square as if it were a crown. In the diagram, White has chosen a Static Rook position, in which the rook remains on its starting square. This Static Rook position is specifically a type of Counter Ranging Rook position known as Bear in the hole Static Rook that uses a Bear in the hole castle. The Bear in the hole fortification has the king moved all the way into very edge corner of the board on the 11 square as if it were a badger in a hole with a silver moved to the 22 square in order to close up the hole and additional reinforcing golds on 31 and 32 squares. This board position required 33 moves (or 12 move pairs as counted in western chess) to construct.

Among amateur tournaments, the higher ranked player or defending champion performs the piece toss. In professional games, the furigoma is done on the behalf of the higher ranked player/champion by the timekeeper who kneels by the side of the higher ranked player and tosses the pawn pieces onto a silk cloth. In friendly amateur games, a player will ask the opponent to toss the pawns out of politeness. Otherwise, the person who tosses the pawns can be determined by Rock–paper–scissors.

There are two organizations for shogi professional players in Japan: the JSA, and the , or LPSA. The JSA is the primary organization for men and women's professional shogi Both organize tournaments for their members and have reached an agreement to cooperate with each other to promote shogi through events and other activities. Top professional players are fairly well paid from tournament earnings. In 2016, the highest tournament earners were Yoshiharu Habu and Akira Watanabe who earned ¥91,500,000 and ¥73,900,000. (The tenth highest earner, Kouichi Fukaura, won ¥18,490,000.) The JSA recognizes two categories of shogi professionals: Professional (棋士), and Female Professional (女流棋士 ). Sometimes kishi are addressed as seikishi (正棋士), a term from Go used to distinguish kishi from other classes of players. JSA professional ranks and female professional ranks are not equivalent and each has their own promotion criteria and ranking system. In 2006, the JSA officially granted women "professional status". This is not equivalent, however, to the more traditional way of "gaining professional status", i. e., being promoted from the "Shoreikai System" (奨励会): leagues of strong amateur players aspiring to become a professional. Rather, it is a separate system especially designed for female professionals. Qualified amateurs, regardless of gender, may apply for the "Shoreikai System" and all those who successfully "graduate" are granted kishi status; however, no woman has yet to accomplish this feat (the highest women have reached is "Shoreikai 3 dan league" by Kana Satomi and Tomoka Nishiyama), so kishi is de facto only used to refer to male shogi professionals. The JSA is the only body which can organize tournaments for professionals, e. g., the eight major tournaments in the titleholder system and other professional tournaments. In 1996, Yoshiharu Habu became the only kishi to hold seven major titles at the same time. For female professionals, both the JSA and LPSA organize tournaments, either jointly or separately. Tournaments for amateurs may be organized by the JSA and LPSA as well as local clubs, newspapers, private corporations, educational institutions or municipal governments for cities or prefectures under the guidance of the JSA or LPSA. Since the 1990s, shogi has grown in popularity outside Japan, particularly in the People's Republic of China, and especially in Shanghai. The January 2006 edition of Kindai Shogi (近代将棋) stated that there were 120,000 shogi players in Shanghai. The spread of the game to countries where Chinese characters are not in common use, however, has been slower.

as of November 2017, in Europe there are currently over 1,200 active players.

Shogi has the highest game complexity of all popular chess variants. Computers have steadily improved in playing shogi since the 1970s. In 2007, champion Yoshiharu Habu estimated the strength of the 2006 world computer shogi champion Bonanza at the level of two dan shoreikai. The JSA prohibits its professionals from playing computers in public without prior permission, with the reason of promoting shogi and monetizing the computer–human events. On October 12, 2010, after some 35 years of development, a computer finally beat a professional player, when the top ranked female champion Ichiyo Shimizu was beaten by the Akara2010 system in a game lasting just over 6 hours. On July 24, 2011, computer shogi programs Bonanza and Akara crushed the amateur team of Kosaku and Shinoda in two games. The allotted time for the amateurs was one hour and then three minutes per move. The allotted time for the computer was 25 minutes and then 10 seconds per move. On April 20, 2013, GPS Shogi defeated 8 dan professional shogi player Hiroyuki Miura in a 102 move game which lasted over 8 hours. On December 13, 2015, the highest rated player on Shogi Club 24 was computer program Ponanza, rated 3455. On April 10, 2016, Ponanza defeated Takayuki Yamasaki, 8 dan in 85 moves. Takayuki used 7 hours 9 minutes. In October 2017, DeepMind claimed that its program AlphaZero, after a full nine hours of training, defeated elmo in a 100 game match, winning 90, losing 8, and drawing two. From a computational complexity point of view, generalized shogi is EXPTIME complete.

Hundreds of video games were released exclusively in Japan for several consoles. Clubhouse Games: 51 Worldwide Classics was released internationally by Nintendo in 2020 for the Nintendo Switch console, offering both Shogi and mini Shogi variants using either traditional or bilingual pieces.

According to professional player Yoshiharu Habu, in Japan shogi is viewed as not merely a game as entertainment or a mind sport but is instead an art that is a part of traditional Japanese culture along with haiku, tanka, noh, ikebana, and the Japanese tea ceremony. Its elevated status was established by the iemoto system supported by the historical shogunate. The backwards uma (shogi horse symbol) is often featured on merchandise (such as on large decorative shogi piece sculptures, keychains, and other keepsakes) available for sale in Tendō. It also serves as a symbol of good luck. (Cf. Rabbit's foot.) There are multiple theories on its origin. One is that uma (うま ) spelled in the Japanese syllabary backwards is まう mau (舞う), which means (to) dance and dancing horses are a good luck omen.

In the manga and anime series Naruto, shogi plays an essential part in Shikamaru Nara's character development. He often plays it with his sensei, Asuma Sarutobi, apparently always beating him. When Asuma is fatally injured in battle, he reminds Shikamaru that the shogi king must always be protected, and draws a parallel between the king in shogi and the children who would grow up to take care of the Hidden Leaf (Konoha) in the future, as well as his yet unborn daughter, Mirai, whom he wanted Shikamaru to guide. Shogi has been a central plot point in the manga and anime Shion no Ō, the manga and anime March Comes in Like a Lion, and the manga and television drama 81diver. In the manga and anime Durarara! !, the information broker Izaya Orihara plays a twisted version of chess, go and shogi, where he mixes all three games into one as a representation of the battles in Ikebukuro. In the video game Persona 5, the Star confidant, a girl named Hifumi Togo, is a high school shogi player looking to break into the ranks of the professionals. The player character will gain a knowledge stat when spending time with the confidant, supposedly from learning to play shogi. The abilities learned from ranking up the confidant comes from Japanese shogi terms. In the manga and anime When Will Ayumu Make His Move?, second year high school student Urushi Yaotome is the president of her school's shogi club, though the club is considered illegitimate due to not having enough members, the only other member being first year student Ayumu Tanaka.