Castle (shogi)

Castles and opening types

Certain castles are generally paired with certain openings. For example, if White is playing a Ranging Rook opening like Fourth File Rook, then White often uses a Mino (or related) castle on their right side of the board. A Fourth File Rook opening can be met with Black playing a Static Rook opening, which may often lead to Black building a Static Rook Anaguma castle.

Yagura

The Yagura or Fortress castle (矢倉囲い yaguragakoi) is considered by many to be the strongest defensive position in shogi in Double Static Rook games.

A common Yagura structure is the Gold Yagura (金矢倉 kin yagura). 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. It is difficult to break down with a frontal assault, though it is weaker from the side. It is typically used against static rook openings that involve advancing the rook's pawn. However, one's opponent may just as easily adopt this defense, giving neither side an advantage.

Crab castle

When building a Yagura castle, there is a strong intermediate position called the Crab castle (カニ囲い kanigakoi). It has the three pawns on the left side advanced to their final Yagura positions, and on the h rank all four generals are lined up next to the bishop, which is still in its starting position: 角金銀金銀 bishop-gold-silver-gold-silver. The king is moved one square to the left, behind the middle silver.

The crab name comes from the way the king at 6i can only move from side to side (7i, 5i).

Bonanza

The Bonanza castle (ボナンザ) is a castle that used to be built by the computer shogi engine Bonanza. It has some similarities with the Incomplete Yagura castle.

Helmet

The Helmet or Headpiece castle (カブト kabuto) castle is a structure often used to protect the king while playing a reclining silver strategy (腰掛け銀 koshikakegin) usually in combination with a bishop-exchange opening. If bishops have already been exchanged, then the silver that originated at 7i will have moved up to 7g via 8h. And, for reclining silver, the silver that originated at 3i will have reached the central file at 5f (through 3h and 4g) with pawn on the fourth file moving up to 4f to make way for the silver. Reclining silver's name comes from the way the silver at 5f appears to sit on top of the 5g pawn and lean back against the 4f pawn. Kabuto is also known as Helmet Yagura (カブト矢倉 or 兜矢倉 kabuto yagura).

Snowroof

Snowroof (雁木 gangi) castle.

Right King

Right King (右玉 migi gyoku)

Central House

Central House (shogi) (中住まい naka zumai)

Nakahara

Nakahara (shogi) (中原囲い nakaharagakoi)

Duck

Duck or Duck Legs (アヒル ahiru) or Spread Golds (金開き kinbiraki) is a Static Rook castle used in the surprise Duck opening.

Truck

Truck castle (トラック囲い torakkugakoi) is an uncommon Static Rook castle.

Boat

The Boat castle (舟囲い or 船囲い funagakoi) is a Static Rook castle used against Ranging Rook, where the king moves next to the bishop and moves the right hand gold diagonally forward above the king's throne. This castle can also be an intermediary towards making stronger castles, such as Left Mino, Silver Crown or Anaguma. This castle is often considered weak although Static Rook has the option of engaging in a rapid attack through various means, especially against 4th file rook and by making use of the left-hand silver.

A rapid attack isn't guaranteed to be successful, since Ranging Rook will try to trade off the bishops and bring the game into a full-scale battle. This can lead static rook into a difficult game, because their Boat castle is too weak compared to the opponent's Mino castle. As such, Static Rook would rather resort to making stronger castles, such as Anaguma or Left Mino.

Daddy's Dearest

Daddy's Dearest or Girl-In-The-House (箱入り娘 hakoiri musume, lit. "daughter inside box") is a development from the Boat castle with the fifth file gold moving to the sixth file getting closer to the king.

Diamond

The Diamond or Lozenge castle (菱囲い hishigakoi) can be developed from a Boat castle by moving the left silver up to 6h and incorporating the right silver above the gold on 5g. The Diamond is relatively stronger than the Boat.

Small/Rapid Castle

This castle is not very common.

Yonenaga King

Yonenaga King castle (米長玉 Yonenaga gyoku) is used for Static Rook vs Ranging Rook games. This castle is named after Kunio Yonenaga.

This castle is similar to an Edge King Silver Crown.

The Yonenaga King variant show here is almost the same as a Left Silver Crown castle but with the king moved leftward one file to the edge. Thus, it may called by the name Yonenaga King Silver Crown (米長玉銀冠 yonenaga gyoku ginkanmuri).

Elephant Eye

Silver Elephant Eye (銀象眼 gin zōgan) and Gold Elephant Eye (金象眼 kin zōgan) may be used in bishop handicap games.

Skewered Cutlet

Skewered Cutlet castle (串カツ kushikatsu) is used for Static Rook vs Ranging Rook games. It is named after a kushikatsu.

The Skewered Cutlet is structurally similar to the Static Rook Anaguma.

The Anaguma or Bear In The Hole castle (穴熊囲い anaguma, lit. "hole-bear") is a very common and often used in professional shogi. (An anaguma is a Japanese badger.)

This castle can be executed on either side of the board.

Mino

The Mino castle (美濃囲い minōgakoi) is a defensive position that is considered easier for beginners, but still popular with professionals. (Mino is a historical province of Japan.) The King is placed in a safe position, while the three generals work well to back each other up.

Silver Crown

The Silver Crown castle (銀冠 ginkanmuri) is often a further development from High Mino.

From a High Mino structure, the pawn above the king moves to 2f allowing the silver to position itself at the head of the king (2g). Then, the gold on 4i moves to 3h to take the silver's former square.

It is also typical for the knight to advance.

Silver Crown is stronger than both Mino and High Mino from above.

Wall

Wall castle (壁囲い kabegakoi), also known as Quick Castle (早囲い hayagakoi), is used for Static Rook vs Ranging Rook games. According to Hosking, it can also be called Edo Castle. It can be formed very quickly if under attack.

(In Japanese, the term 早囲い hayagakoi also refers to Quick Yagura castle.)

The Wall castle can develop later into the stronger Gold Mino with two moves.

Flatfish

Flatfish (shogi) (平目囲い or ヒラメ囲い hiramegakoi)

Millenium

Millenium (shogi) (ミレニアム mireniamu) is a newer castle developed in response to the Fuji System (藤井システム Fuji shisutemu) opening.

Aerokin

This castle usually develops when your opponent tries to attack your silver crown.

Twin Gold

Twin Gold (二枚金 nimaikin) or "Silver Wall" is a castle used in Double Ranging Rook openings. It's also called Peerless Golds (金無双 kinmusō).

Aerial Tower

Aerial Tower (空中楼閣 kūchū rōkaku) is a Mid-Rank King (中段玉 chūdan gyoku) type of castle in which the king is positioned on the middle d-f ranks.

Fourth Rank Edge King

Fourth Rank Edge King (四段端玉 yondan hashigyoku) is a Mid-Rank type of castle.