Shogi Strategy and Tactics - Opening - The Yagura Castle

The Yagura Castle

The Yagura castle (矢倉囲い Yagura gakoi) is considered by many to be the strongest defensive 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. It is notoriously 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, and the possibilities will not be listed here. The only point to keep in mind is that the generals should move diagonally, not directly forward. However, there is a strong intermediate position called the kani ("crab"). It 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: |B|G|S|G|S| bishop-gold-silver-gold-silver. The king is moved one square to the left, behind the middle silver.

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.

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. 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.