Central House (nakazumai) is a balanced King structure associated with open, fluid positions such as Double Wing Attack. It is a real destination in suitable openings, not merely a waiting room before Mino Castle.
Reference Shape
A representative Sente shape places the King on 5h, with Golds and Silvers spread across the fourth through seventh files. The broad formation values escape routes and balance more than a dense wall.
When It Fits
Central House fits positions where attacks can come from both wings and where a deeply castled King would take too long or become a fixed target. It is especially connected with Rook exchanges and wide boards, not with a generic Ranging-Rook plan.
Strength and Risk
The King has several escape directions and the generals can support both wings. The same openness means checks may arrive from more directions. Pieces in hand and open files matter more than the castle’s name.
Study Task
Compare two positions with the King on 5h: one with open files and useful escape squares, and one where an opposing Rook or Bishop already controls the center. The surrounding lines determine whether the King is balanced or exposed.
Test What Balanced Means on This Board
The King on 5h is supported laterally by Golds on 4h and 6h. Silvers on 3h and 7h extend the formation toward both wings. Unlike a dense corner castle, the pieces are spread across five files. That geometry creates several possible routes, but it also means checks can approach from more than one direction.
Open Position Checklist
- Rook lines: identify any open file or rank that reaches the fifth file.
- Bishop lines: trace both diagonals through and around 5h.
- Pieces in hand: mark checking drops near 4g, 5g, 6g, 4i, 5i, and 6i.
- Escape quality: a square is useful only if the opponent does not control it.
| Position | Interpretation |
|---|---|
| Open wings, no forcing central check | The broad formation may preserve useful routes. |
| Opponent controls the fifth file or both diagonals | The central King may be exposed rather than flexible. |
| Major pieces are likely to exchange | Recalculate every drop square before calling the King safe. |
Do Not Turn an Association into a Rule
Central House is associated with open positions such as Double Wing Attack, but that association does not make 5h correct in every open game. The displayed position is deliberately sparse so learners can inspect the defensive spread. A real move choice must use the full board.
Sources and Scope
Rule statements are checked against the current Japan Shogi Association playing rules. Castle terminology and opening pairings were cross-checked with the Japan Shogi Association beginner-course material. The board on this page is a 51Shogi coordinate reference, not a claim that one final arrangement or move order is mandatory in every opening.
