Yagura (shogi)

Yagura or Fortress (矢倉 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 (相居飛車 aiibisha) opening, which is often a Double Yagura (相矢倉 aiyagura) opening. However, it may also occur in different Double Static Rook openings such as Yagura vs Right Fourth File Rook.

The Yagura castle (矢倉囲い yagura gakoi), which is the defining characteristic of Yagura games, is considered by many to be one of the strongest defensive positions in Double Static Rook games.^[1]

The term yagura is the Japanese word for a tower-like structure in traditional Japanese castles.

Yagura castle

Gold Yagura (Black)

9	8	7	6	5	4	3	2	1
									a
									b
									c
									d
									e
									f
									g
									h
									i

Gold Yagura (White)

9	8	7	6	5	4	3	2	1
									a
									b
									c
									d
									e
									f
									g
									h
									i

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.

There is a good deal of flexibility in the order of moves when building the Yagura defense. A point to keep in mind is that the generals should move diagonally, not directly forward.^[1]

While forming the castle, the rook's pawn is often advanced two squares in preparation for a climbing rook assault on the opposing king. Another common preparation is to advance the adjacent silver's pawn square, allowing passage for both the rook's silver and knight. These offensive moves are not properly part of the castle, 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.^[1]

Crab

Crab

9	8	7	6	5	4	3	2	1
									a
									b
									c
									d
									e
									f
									g
									h
									i

When building a Yagura castle, there is a strong intermediate position called the Crab castle (カニ囲い kani gakoi).^[1]^[2] 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).

Attacking Yagura

A common attack against the Yagura defense is to advance the rook's knight directly forward, defended by the rook and with a pawn in hand, to attack the fortifications on either side of the castled king.^[1] 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.

Double Yagura

Yagura Castle

△

9	8	7	6	5	4	3	2	1
									a
									b
									c
									d
									e
									f
									g
									h
									i

▲

Yagura
up to move 2
△ Pieces-in-hand: none

9	8	7	6	5	4	3	2	1
									a
									b
									c
									d
									e
									f
									g
									h
									i

▲ Pieces-in-hand: none
1. P-7f P-8d

Yagura
up to move 3
△ Pieces-in-hand: none

9	8	7	6	5	4	3	2	1
									a
									b
									c
									d
									e
									f
									g
									h
									i

▲ Pieces-in-hand: none
2. S-6h ...

Yagura
up to move 4
△ Pieces-in-hand: none

9	8	7	6	5	4	3	2	1
									a
									b
									c
									d
									e
									f
									g
									h
									i

▲ Pieces-in-hand: none
2. ... P-3d

Blocking bishop with pawn

Yagura
up to move 5
△ Pieces-in-hand: none

9	8	7	6	5	4	3	2	1
									a
									b
									c
									d
									e
									f
									g
									h
									i

▲ Pieces-in-hand: none
3. P-6f ...

Yagura
up to move 6
△ Pieces-in-hand: none

9	8	7	6	5	4	3	2	1
									a
									b
									c
									d
									e
									f
									g
									h
									i

▲ Pieces-in-hand: none
3. ... S-6b

At move 6, White has also has an option to play Climbing Silver by advancing their rook pawn to the e rank. (See: White Climbing Silver.)

Yagura
up to move 7
△ Pieces-in-hand: none

9	8	7	6	5	4	3	2	1
									a
									b
									c
									d
									e
									f
									g
									h
									i

▲ Pieces-in-hand: none
4. P-5f ...

Yagura
up to move 10
△ Pieces-in-hand: none

9	8	7	6	5	4	3	2	1
									a
									b
									c
									d
									e
									f
									g
									h
									i

▲ Pieces-in-hand: none
4. ... P-5d
5. S-4h S-4b

Yagura
up to move 11
△ Pieces-in-hand: none

9	8	7	6	5	4	3	2	1
									a
									b
									c
									d
									e
									f
									g
									h
									i

▲ Pieces-in-hand: none
6. G4i-5h ...

Yagura
up to move 14
△ Pieces-in-hand: none

9	8	7	6	5	4	3	2	1
									a
									b
									c
									d
									e
									f
									g
									h
									i

▲ Pieces-in-hand: none
6. ... G-3b
7. G-7h K-4a

Yagura
up to move 15
△ Pieces-in-hand: none

9	8	7	6	5	4	3	2	1
									a
									b
									c
									d
									e
									f
									g
									h
									i

▲ Pieces-in-hand: none
8. K-6i ...

Crab Castle

△

9	8	7	6	5	4	3	2	1
									a
									b
									c
									d
									e
									f
									g
									h
									i

▲

New Yagura 24-Move Set

New Yagura 24-Move Set (新矢倉24手組 shin yagura nijū-tegumi)

Yagura
up to move 24
△ Pieces-in-hand: none

9	8	7	6	5	4	3	2	1
									a
									b
									c
									d
									e
									f
									g
									h
									i

▲ Pieces-in-hand: none

Blocking bishop with silver

Yagura
up to move 5
△ Pieces-in-hand: none

9	8	7	6	5	4	3	2	1
									a
									b
									c
									d
									e
									f
									g
									h
									i

▲ Pieces-in-hand: none
3. S-7g ...

Blocking White's bishop with a silver (and also defending the eighth file from a possible attack) is an older Yagura 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.)

Old Yagura 24-Move Set

(Old) Yagura 24-Move Set (矢倉24手組 yagura nijū-tegumi)

Old Yagura
up to move 24
△ Pieces-in-hand: none

9	8	7	6	5	4	3	2	1
									a
									b
									c
									d
									e
									f
									g
									h
									i

▲ Pieces-in-hand: none

Compared to the New Yagura 24-Move Set, note that the Old Yagura 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 6g variant

Right Gold To 6g (6七金右 roku-nana kin migi)

Right Gold to 6g
up to move 25
△ Pieces-in-hand: none

9	8	7	6	5	4	3	2	1
									a
									b
									c
									d
									e
									f
									g
									h
									i

▲ Pieces-in-hand: none
25. G5h-6g ...

Right Gold to 6g
up to move 26
△ Pieces-in-hand: none

9	8	7	6	5	4	3	2	1
									a
									b
									c
									d
									e
									f
									g
									h
									i

▲ Pieces-in-hand: none
25. ... G5b-4c

Spearing the Sparrow

Spearing the Sparrow (雀刺し suzume-zashi)

Spearing the Sparrow
up to move 25
△ Pieces-in-hand: none

9	8	7	6	5	4	3	2	1
									a
									b
									c
									d
									e
									f
									g
									h
									i

▲ Pieces-in-hand: none
25. P-1f ...

White Yagura Climbing Silver

White Climbing Silver
up to move 6
△ Pieces-in-hand: none

9	8	7	6	5	4	3	2	1
									a
									b
									c
									d
									e
									f
									g
									h
									i

▲ Pieces-in-hand: none
3. ... P-8e

White Climbing Silver
up to move 7
△ Pieces-in-hand: none

9	8	7	6	5	4	3	2	1
									a
									b
									c
									d
									e
									f
									g
									h
									i

▲ Pieces-in-hand: none
4. S-7g ...

Yagura vs Right Fourth File Rook

Another Double Static Rook game includes playing Right Fourth File Rook against a Yagura position.

References

1 2 3 4 5 Fairbairn 1984.
↑ Hosking 1997, p. 46, Part 1, Chapter 8: Castles.

Bibliography

Aono, Teruichi (2009) [1983]. Better moves for better shogi. Translated by Fairbairn, John (2nd ed.). Ishi Press. ISBN 978-4-87187-999-6.
Aono, Teruichi (1983). Guide to shogi openings: Shogi problems in Japanese and English 将棋定跡のカギ: 和英定跡問題集. Translated by Fairbairn, John. 山海堂. ISBN 4-381-00598-8.
Fairbairn, John (1984). Shogi for Beginners. Ishi Press. ISBN 978-4-8718-720-10.
Hosking, Tony (1997). The art of shogi. The Shogi Foundation. ISBN 978-0-95310-890-9.
Kitao, Madoka (2011). Joseki at a glance. Translated by Kawasaki, Tomohide. Nekomado. ISBN 978-4-9052-2501-0.
"kieta senpō no nazo" 消えた戦法の謎 [Quest of the lost systems]. Shogi.Net. Mainichi Communications Co. 1995. · Partial translation of 消えた戦法の謎 kieta senpō no nazo by Kiyokazu Katsumata.

External links

This article is issued from Wikipedia - version of the 11/17/2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.