Openings · 右四間飛車急戦
Right Fourth File Rook Rapid Attack.
Seat the right silver on 5f, put the rook on 4h, and jump the knight to 2e to break open the fourth file against a Fourth File Rook.
The idea
This is the rapid-attack branch of the Right Fourth File Rook; that page shows the slower one, with the king in a Left Mino. Against a Fourth File Rook, Black leaves the fifth-file pawn at home and pushes the fourth-file pawn instead, seats the right silver on 5f and swings the rook to 4h, the fourth file counted from the right.
The king stops in a Boat that keeps its silver on 7i. Then the knight jumps 3g, 2e at the bishop on 3c, and Black gives it up for the push to 4e: silver and rook come in on the fourth file. ja.wikipedia traces this exact line to a book of 1804, 『将棋絹篩』, and both ja.wikipedia and shogilounge stress that it is what happens when White plays naturally.
How it goes together
Both sides’ moves are shown, because this opening is an agreement rather than a system: one player cannot reach it alone, so a one-sided list of moves would be a fiction.
Step through the moves, or press play.
Tap a move to jump to it. Arrow keys work once the board has focus.
Every move of the line, with reasons
| # | Black | White | Why |
|---|---|---|---|
| 1 | ▲２六歩 2g2f | △３四歩 3c3d | The rook pawn first. |
| 3 | ▲７六歩 7g7f | △４四歩 4c4d | Then the bishop’s diagonal. White closes its diagonal. |
| 5 | ▲４六歩 4g4f | △４二飛 8b4b | The fourth-file pawn, not the fifth. White swings to 4b. |
| 7 | ▲４八銀 3i4h | △６二玉 5a6b | The right silver starts. |
| 9 | ▲４七銀 4h4g | △７二玉 6b7b | To 4g. |
| 11 | ▲５六銀 4g5f | △３二銀 3a3b | To 5f: the silver sits on the fifth file. |
| 13 | ▲４八飛 2h4h | △４三銀 3b4c | The rook to 4h, the fourth file from the right. White’s silver to 4c. |
| 15 | ▲６八玉 5i6h | △８二玉 7b8b | Now the king walks left. |
| 17 | ▲７八玉 6h7h | △７二銀 7a7b | King on 7h. |
| 19 | ▲９六歩 9g9f | △９四歩 9c9d | |
| 21 | ▲３六歩 3g3f | △３三角 2b3c | Room for the knight. White’s bishop comes out to 3c. |
| 23 | ▲５八金右 4i5h | △５四銀 4c5d | The right gold to 5h: a Boat that keeps its silver on 7i. White’s silver to 5d. |
| 25 | ▲３七桂 2i3g | △５二金左 4a5b | The knight to 3g. |
| 27 | ▲２五桂 3g2e | △２二角 3c2b | The knight jumps to 2e and hits the bishop. The bishop drops back to 2b. |
| 29 | ▲４五歩 4f4e | △２四歩 2c2d | The break. White attacks the knight with 2d. |
| 31 | ▲４四歩 4e4d | △２五歩 2d2e | Black pushes on to 4d. White takes the knight: Black has given it up. |
| 33 | ▲４五銀 5f4e | △同銀 5d4e | The silver to 4e. White’s silver takes. |
| 35 | ▲同飛 4h4e | The rook takes back on 4e. |
The plan once you are set up
- Push the fourth-file pawn, not the fifth, and seat the right silver on 5f by 4h and 4g.
- Swing the rook to 4h and castle in a Boat that keeps the 7i silver.
- Bring the knight to 3g and jump it to 2e at the bishop on 3c.
- Push 4e and let the knight go; then the silver and the rook break in on the fourth file.
What to watch for
- White’s known answers: the gold kept back on 4a with the lance on 1b, and the silver left on 4c, which shogilounge calls the clear way.
- The sources stress that this line is what happens when White plays naturally; a White who knows the answers does not let it run this way.
What it is played against
A Fourth File Rook with a Mino. White’s known answers are the gold kept on 4a with the lance on 1b, and keeping the silver on 4c. The Left Mino form on the Right Fourth File Rook page is the slower way to use the same rook move.
Play it against the bot.
The bot’s search levels, 9 to 12, open from a book that holds two of these openings, the Fourth File Rook and the Yagura; the Mino levels play the openings people play. Either way the review afterwards shows you where the game left the line. Try the line, then try the plan.