Openings · 角頭歩戦法
Bishop Head Pawn.
Push the pawn in front of your own bishop; when White pushes the rook pawn, trade bishops, jump the knight to 7g and swing the rook to the sixth file.
The idea
The Bishop Head Pawn breaks a basic rule: Black pushes the pawn that guards the bishop’s head, to 8f. If White answers with the rook pawn to 8d, Black trades bishops and jumps the knight to 7g at once, so the eighth file is shut and the knight is already out. Black then plays a ranging rook, and the early knight helps the attack.
Yonenaga Kunio played it in professional games in the 1960s and 1970s; the first five moves here are the order ja.wikipedia gives for his game against Nishimura in 1964. White can avoid all of it by closing the diagonal with the pawn to 4d on move four, as Nakahara Makoto did against Yonenaga in the 1975 Ōshō title match.
The line after the knight jump follows shogi-rule.com, the one source with every move; it heads the line as a static rook plan, but the rook ends on 6h, a Fourth File Rook. White’s own version, with the pawn in front of White’s bishop, is White’s Bishop Head Pawn.
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 | ▲７六歩 7g7f | △３四歩 3c3d | Open the bishop’s diagonal. White opens its own. |
| 3 | ▲９六歩 9g9f | △１四歩 1c1d | The edge pawn first. White answers on the other edge. |
| 5 | ▲８六歩 8g8f | △８四歩 8c8d | The pawn in front of the bishop goes to 8f: the name. White pushes the rook pawn, heading for the eighth file. |
| 7 | ▲２二角成 8h2b+ | △同銀 3a2b | Black trades bishops. The silver takes back. |
| 9 | ▲７七桂 8i7g | △３三銀 2b3c | The point: the knight jumps to 7g at once and shuts the eighth file. White’s silver to 3c. |
| 11 | ▲７八金 6i7h | △６二銀 7a6b | The left gold to 7h. White’s right silver to 6b. |
| 13 | ▲６六歩 6g6f | △６四歩 6c6d | The sixth-file pawn to 6f. White pushes its sixth-file pawn too. |
| 15 | ▲５八金 4i5h | △６三銀 6b6c | The right gold to 5h. White’s silver on to 6c. |
| 17 | ▲６七金右 5h6g | △７四歩 7c7d | The right gold steps up to 6g. White pushes the seventh-file pawn. |
| 19 | ▲５六金 6g5f | △６二金 6a6b | And the gold climbs on to 5f. White’s right gold to 6b. |
| 21 | ▲６八飛 2h6h | △５四角 B*5d | The rook swings to 6h: a Fourth File Rook. White drops its bishop on 5d. |
| 23 | ▲３六歩 3g3f | △７六角 5d7f | The third-file pawn to 3f. White’s bishop takes the pawn on 7f. |
| 25 | ▲６五歩 6f6e | △同歩 6d6e | The pawn to 6e. White takes. |
| 27 | ▲３七角 B*3g | Black drops a bishop on 3g: through 6d and 7c it looks at the rook on 8b. |
The plan once you are set up
- Open the diagonal with 7f, push the edge pawn, then push the pawn in front of the bishop to 8f.
- When White pushes the rook pawn to 8d, trade bishops and jump the knight to 7g.
- Gold to 7h, the sixth-file pawn up, the right gold to 6g and on to 5f.
- Swing the rook to 6h and use the bishop in hand.
What to watch for
- A bishop dropped on 8g, in the hole the pawn left. ja.wikipedia shows it failing: Black’s own bishop dropped on 6e guards the pawn on 7f and threatens to promote on 4c, and after the trade Black comes out a bishop for a silver ahead.
- White closing the diagonal with the pawn to 4d on move four. Then there is no bishop trade, and ja.wikipedia’s example swings the rook to 8h for an Opposing Rook.
- In that Opposing Rook line, do not jump the knight to 6e before the king has moved: ja.wikipedia warns of a bishop dropped on 7g that forks the king and the rook.
What it is played against
A static rook that opens its bishop and pushes the rook pawn. White can avoid it all by closing the diagonal with the pawn to 4d on move four, as Nakahara did, and the game turns into an Opposing Rook without the bishop trade.
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.