The Double Fortress (相矢倉 or 相櫓 ''aiyagura'') is a
shogi opening
A shogi opening ( ) is the sequence of initial moves of a shogi game before the middle game. The more general Japanese term for the beginning of the game is ()''.''
A '' jōseki'' () is the especially recommended sequence of moves for a given o ...
in which both players construct
Fortress formations.
Double Fortress games are the most common type of Fortress games found at all levels of play.
Historical Fortress
Earlier josekis for Fortress in the
Edo period
The or is the period between 1603 and 1867 in the history of Japan, when Japan was under the rule of the Tokugawa shogunate and the country's 300 regional '' daimyo''. Emerging from the chaos of the Sengoku period, the Edo period was characte ...
(usually spelled 櫓 at that time) were very different from the current josekis.
In one variation, White delays pushing their rook pawn (whereas Black delays the rook pawn push in the modern era) and there is an early bishop trade before both players' kings are moved into their castles.
In the 1947
Meijin tournament,
Masao Tsukada and
Yoshio Kimura played an early example of the typical 3. S-77 type of Fortress with 1.P-76 P-84 development found in modern shogi.
1. P-76 P-84 development
3. S-77: Blocking bishop with silver
Blocking White's bishop with a silver (and also defending the eighth file from a possible attack) is an older Fortress joseki, which typically also includes advancing Black's rook pawn.
The more recent joseki advances Black's pawn on the sixth file instead. (See
above.)
Classic Fortress 24-Move Set
Classic Fortress 24-Move Set (旧矢倉24手組 ''kyū yagura nijū-tegumi'')
Compared to the
New Fortress 24-Move Set, note that the Classic Fortress 24-Move Set is (a) symmetrical where both sides have the same formation and (b) that only Black's formation differs (White's formation is the same in both the old and new josekis.)
=Right Gold to 67 variant
=
Right Gold To 67 (6七金右 ''roku-nana kin migi'')
=Spearing the Sparrow
=
Spearing the Sparrow
In shogi, Spearing the Sparrow (雀刺し or スズメ刺し ''suzumezashi'') is one of the substrategies of the Fortress (Static Rook) class of openings. The strategy is basically an edge attack on the first file if played by Black or the ninth ...
(雀刺し ''suzume-zashi'')
3. P-66: Blocking bishop with pawn
At move 6, White also has an option to play Climbing Silver by advancing their rook pawn to rank 5. (See:
White Climbing Silver.)
New Fortress 24-Move Set
New Fortress 24-Move Set (新矢倉24手組 ''shin yagura nijū-tegumi'')
Quick Fortress castling
Quick Fortress castling
White's Fortress Climbing Silver
Silver-37 variations
After the 24-move set of the Fortress opening, one major branch in the Fortress strategies is the Silver-37 set of variations. Many variations are under this parent variation.
Katō variation
Named after
Hifumi Katō
is a retired Japanese professional shogi player who achieved the rank of 9-dan.
He is a former Meijin, Tenth Dan, Ōi, Kiō and Ōshō major title holder.
He has the nicknames ''123'', is composed of the characters ja, 一, translit=hi, lab ...
.
Waki System
Morishita System
The Morishita System delays moving the right attacking silver to 37 early. Instead, it simply moves the bishop to 68 allowing the king to move into the Fortress castle in subsequent moves.
Other development patterns
1. P-76 P-34 2. P-66 patterns
Additionally, earlier Fortress openings in the first part of the 20th century did not follow from the standard 1. P-76 P-84 opening used today and instead developed from mutual opening of the bishop diagonals with 1. P-76 P-34.
Fortress development from Bishop Exchange
A Fortress position may also be developed from a rejected
Bishop Exchange opening. For example, after a Bishop Exchange setup, instead of White trading the bishops off the board, White may choose to reject the bishop trade by closing their bishop diagonal. At this point, both players may convert their left side configurations into Fortress castles by pulling their bishops back and moving their silvers to the 77 and 33 squares. Thus, Black may move their bishop to 68 (or to 59 if their king moves to 69 first) allowing their left silver to move to 77. Likewise, White may move their bishop to 33 (usually triggered by Black pushing their rook pawn to 25), move their left silver to 22, move their bishop to 42 allowing their left silver to move 33.
Although possible, this Fortress development is not very common among professional players. When White rejects the bishop trade in this way, it is more common for White to play a
Snowroof position while Black switches to a Fortress position instead of a Double Fortress game.
Game example
Hirokazu Ueno vs
Keiji Nishikawa 2008.
See also
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Fortress opening
Fortress (矢倉 or 櫓 ''yagura'') is both a Static Rook opening (矢倉戦法 ''yagura senpō'') and a castle in shogi.
It is usually played in a Double Static Rook opening, which is often a Double Fortress opening. However, it may also occu ...
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Fortress castle
Fortress or Yagura (矢倉囲い or 櫓囲い ''yaguragakoi'') is a castle used in shogi. It is considered by many to be the strongest defensive position in shogi in Double Static Rook games.
The most common form of Fortress is the Gold Fortres ...
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Static Rook
Static Rook (居飛車 ''ibisha'') openings in shogi typically have the player's rook at its start position, which is the second file (on the 28 square) for Black and the eighth file (on the 82 square) for White.
Explanation
Static Rook is a ...
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Shogi opening
A shogi opening ( ) is the sequence of initial moves of a shogi game before the middle game. The more general Japanese term for the beginning of the game is ()''.''
A '' jōseki'' () is the especially recommended sequence of moves for a given o ...
Bibliography
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* · Partial translation of 消えた戦法の謎 kieta senpō no nazo by Kiyokazu Katsumata.
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References
External links
* How to Defend in Shogi (by
Yasuharu Ōyama
Yasuharu Ōyama (大山 康晴 Ōyama Yasuharu, March 13, 1923 - July 26, 1992) was a professional shogi player, 15th Lifetime Meijin and president of Japan Shogi Association (1976 - 1989). He studied shogi under . He won 80 titles (2nd on record ...
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Basic Formation 4: Yagura*
* YouTube Hidetchi's:
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Yagura #1*
Rapid Encountered Yagura, Primitive Climbing Silver* Shogifan 将棋ファン
Yagura -1 矢倉* Shogi Openings (professional Akira Nishio's blog):
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* Shogi Shack:
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* Yoshiharu Habu and Modern Shogi
Chapter 1: Yoshiharu Habu and the ''Changing Modern Shogi''*
Chapter 1: Yoshiharu Habu and the ''Changing Modern Shogi''*
Chapter 6: Akira Watanabe, Who Utilized the Window of Opportunity* Yamajunn's Basic Shogi Opening:
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* Shogi Opening:
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* Yet Another Shogi Site:
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Yagura Rapid Attack: Yonenaga/Fujimori style against ▲P35 variation*
Double Yagura: Identical formation* Quest of the Lost Systems
Yagura: R-2i Formation* Global Shogi
* Shogi Maze:
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* 将棋タウン
{{Shogi openings
Shogi openings
Static Rook openings
Fortress openings