Fourth File Rook (shikenbisha) is a Ranging-Rook opening. For Sente, the defining Rook square is 6h, not file 4. The name describes the fourth file counted from the right edge of Sente’s camp.
Reference Position
Legal Development Milestones
- Open the Bishop diagonal when appropriate with 7g-7f.
- Move the Rook directly from 2h to 6h while the back-rank path is clear.
- Move the King away from the Rook through 5i-4h-3h-2h, if the opponent’s threats allow it.
- After the King passes through 3h, develop the Silver from 3i to 3h.
- Use the 6-file Pawn, usually beginning with 6g-6f, when it supports a concrete plan.
These are Sente-side milestones. They are not consecutive moves in a real game because Gote replies after every move, and those replies can change the order.
What the Opening Is Trying to Achieve
The Rook supports play on the 6-file while the King moves to the opposite wing. The Bishop, left Silver, Knights, and Pawns must still cooperate; simply placing the Rook on 6h does not create an attack.
Common Study Errors
- Calling a Rook on 4h “Fourth File Rook.” That is the wrong destination.
- Trying to place the King on 8h while the Bishop still occupies 8h.
- Advancing the wrong Pawn because the English opening name was mistaken for a board coordinate.
- Completing Mino automatically while the opponent has a forcing attack.
First Repertoire Goal
Learn one calm setup, one response to an early Static-Rook attack, and the purpose of the 6-file Pawn break. Review the first position where your planned setup became unsafe.
Why Fourth File Means 6h for Sente
Standard shogi files are numbered 9 through 1 from left to right when Sente is shown at the bottom. The opening name counts from Sente’s right edge: file 1 is first, file 2 second, file 3 third, and file 4 fourth. The fourth file from that edge is therefore coordinate file 6, so the Sente Rook’s reference square is 6h.
Check the Route from the Initial Position
| Move or route | What must be true |
|---|---|
| Rook 2h-6h | Squares 3h, 4h, and 5h are empty; the Rook does not jump. |
| King 5i-4h-3h-2h | Each destination is empty and not controlled by an opposing piece at that moment. |
| Pawn 6g-6f | The move supports a concrete 6-file plan and does not ignore a forcing reply. |
The diagram is a reference position, not a claim that these moves can be played consecutively against every reply. Use the board’s legal-move display to inspect geometry, then test the same plan in a complete game position.
Source Boundary
The Japan Shogi Association beginner material includes a Fourth File Rook and High Mino pairing as an example, not as a compulsory recipe. Movement, King safety, and illegal-move checks follow the current Japan Shogi Association playing rules.
