Openings · 後手角頭歩
White’s Bishop Head Pawn.
Push the pawn in front of your own bishop and invite Black’s rook pawn exchange, then trade bishops, jump the knight to 3c and offer the rook on 2b.
The idea
This line is White’s, and it is a different trap from Black’s Bishop Head Pawn. After Black’s 2f, you push the pawn to 2d, in front of your own bishop, and the natural reply, the pawn to 2e, lets Black exchange rook pawns. You trade bishops on 8h and jump the knight to 3c.
Now the rook going back to 2h would meet a pawn dropped on 2g and a bishop dropped on 4e, so Black promotes the rook instead, and you offer your own rook with the rook to 2b. ja.wikipedia calls the pawn dropped on 2d Black’s best try there.
It ends with a tokin on 2c, but no pawn in Black’s hand, the king still on 5i and your knight on 4e, and ja.wikipedia judges White’s game the easier one. The line is ja.wikipedia’s, which draws on Katō Jirō quoting the amateur Enomoto, who said his games usually reached the knight jump to 4e; it has that one source.
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 | Black opens the bishop’s diagonal. You open yours. |
| 3 | ▲２六歩 2g2f | △２四歩 2c2d | Black pushes the rook pawn: a static rook. The pawn in front of your own bishop goes to 2d. |
| 5 | ▲２五歩 2f2e | △同歩 2d2e | The natural reply, and the one the opening wants. You take. |
| 7 | ▲同飛 2h2e | △８八角成 2b8h+ | Black’s rook takes back and stands on 2e. You trade bishops on 8h. |
| 9 | ▲同銀 7i8h | △３三桂 2a3c | Black’s silver takes back. The knight jumps to 3c. If the rook goes back to 2h now, a pawn on 2g and a bishop on 4e follow. |
| 11 | ▲２三飛成 2e2c+ | △２二飛 8b2b | Black promotes the rook on 2c. You offer your own rook on 2b. |
| 13 | ▲２四歩 P*2d | △２三飛 2b2c | Black’s best try: a pawn dropped on 2d to support the dragon. You take the dragon. |
| 15 | ▲同歩成 2d2c+ | △４五桂 3c4e | Black’s pawn takes your rook and promotes. The knight jumps to 4e. Enomoto said his games usually reached this point. |
| 17 | ▲４八金 4i4h | △６二玉 5a6b | Black’s right gold to 4h. The king steps to 6b. Black has no pawn in hand and cannot easily get one back; ja.wikipedia calls White’s game the easier one. |
The plan once you are set up
- After Black’s 7f and 2f, push the pawn to 2d.
- After the pawn exchange, trade bishops on 8h and jump the knight to 3c.
- Meet the promoted rook with your rook on 2b.
- Jump the knight to 4e and step the king to 6b.
What to watch for
- A Black player who does not exchange. Guarding with the king to 6h or the gold to 7h first was long held to be the best answer, and then there is no trap.
- The rook going back to 2h after the knight jump: answer with a pawn dropped on 2g and a bishop dropped on 4e.
- Black promoting on 2a instead of 2c. ja.wikipedia shows White better there too, after the rook offer on 2b.
What it is played against
Not exchanging at once. ja.wikipedia says guarding with the king to 6h or the gold to 7h first was long held to be the best answer; in a 2016 professional game White met it with the centre pawn to 5d and an Opposing Rook, and the question is not settled.
If Black does exchange and White offers the rook on 2b, the pawn dropped on 2d is the try that holds out longest.
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.