Openings · 勇気流
Yūki Side Pawn.
Against the bishop to 3c, leave the rook on 3d, step the king to 6h beside the gold, and bring the right knight straight out.
The idea
The Yūki line is a cousin of the Aono line. Black skips the rook retreat, pushes the 3rd-file pawn and jumps the right knight to 3g and 4e. The difference is the king: on 6h it guards the gold on 7h.
In the Aono line, when White takes the side pawn back with the rook, Black has to block the bishop trade on 8h and the rook promoting on 7h before the knight can move; here the knight comes out at once. The drawback, a Mynavi article notes, is that the king stands close to any fight on the 7th and 8th files.
Sasaki Yūki developed it and received the Masuda Award for it, announced in 2018, alongside Aono Teruichi for his line. The line here has one source for its order, and its White moves are quiet ones that let the knight in: it shows the idea, not White’s best play, which the sources do not settle.
The king stands where the Strawberry puts it, but the line does not build that castle.
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 | ▲２六歩 2g2f | △８四歩 8c8d | The rook pawn. White pushes its rook pawn. |
| 5 | ▲２五歩 2f2e | △８五歩 8d8e | The pawn to 2e. White’s to 8e. |
| 7 | ▲７八金 6i7h | △３二金 4a3b | The gold to 7h guards the bishop’s head. White’s gold to 3b guards its own. |
| 9 | ▲２四歩 2e2d | △同歩 2c2d | The pawn on to 2d, to exchange it. White takes. |
| 11 | ▲同飛 2h2d | △８六歩 8e8f | The rook takes back. White exchanges on its side too. |
| 13 | ▲同歩 8g8f | △同飛 8b8f | Take back with the pawn. White’s rook takes back. |
| 15 | ▲３四飛 2d3d | △３三角 2b3c | The rook takes the side pawn on 3d. It now threatens to trade bishops on 2b, winning a gold or making a dragon. White’s bishop to 3c blocks the trade. |
| 17 | ▲６八玉 5i6h | △７六飛 8f7f | The opening’s move: the king to 6h, beside the gold on 7h, which it now guards. The rook stays on 3d. White takes the side pawn back with the rook. |
| 19 | ▲３六歩 3g3f | △５二玉 5a5b | Push the 3rd-file pawn anyway. White’s king to 5b. |
| 21 | ▲３七桂 2i3g | △７二金 6a7b | The knight jumps to 3g at once. With the king guarding the gold, the bishop trade on 8h and the rook to 7h no longer work. White’s right gold to 7b. |
| 23 | ▲２二歩 P*2b | △同銀 3a2b | A pawn dropped on 2b, at the knight. White’s silver takes it. |
| 25 | ▲４五桂 3g4e | The knight jumps to 4e, at the bishop. Wherever the bishop goes, the rook promotes on 3b. The source calls the position winning for Black. |
The plan once you are set up
- After the bishop to 3c, step the king to 6h instead of pulling the rook back.
- If White takes the side pawn back with the rook, ignore it and push the 3rd-file pawn.
- Jump the knight to 3g.
- Drop a pawn on 2b to pull a defender onto it, then jump the knight to 4e, at the bishop.
What to watch for
- The bishop trade and a bishop dropped on 2g, at the gold on 4i, which the king on 6h no longer covers. The silver to 3h, and the rook to 2d when the bishop promotes on 4e, gives Black two threats: the rook promoting on 2a and a bishop dropped on 7g.
- The king’s diagonal stays open, one guide notes: with the rook on 8d, a bishop dropped on 9e can fork the king and the rook.
- White’s moves here are passive. The sources do not say what White’s best answer to the king on 6h is.
What it is played against
White takes the side pawn back with the rook, or trades bishops at once and drops one on 2g, at the gold the king no longer guards.
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.