Openings · 一手損角換わり
Tempo Loss Bishop Exchange.
White trades bishops on 8h before Black’s bishop has moved. It costs a move, and in return the rook’s pawn can stay on 8d, which keeps 8e free for White’s knight.
The idea
This is an opening for White. In the ordinary Bishop Exchange, Black puts the bishop on 7g and White takes there, and the trade costs neither side a move. Here White takes on 8h while Black’s bishop is still at home. Black recaptures with the silver from 7i, developing it in the same move, and White ends up a move behind on top of moving second. Two things make that playable.
In a Bishop Exchange neither side can attack easily, so waiting moves matter and one lost move hurts less than in most openings; White also sees one more of Black’s moves before choosing a setup. And White never has to push the rook’s pawn to 8e.
With the pawn on 8d, the 8e square stays empty, and the knight on 7c can jump there, to attack or to escape when Black goes for its head. Both kings use the Bishop Exchange castle: for Black the Helmet Yagura, king 7i, golds 7h and 5h, silver 7g; for White the same shape turned round, king 3a, golds 3b and 5b, silver 3c.
Awaji Hitoshige created the opening and won the 2006 Masuda Kōzō Award for it.
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 | Black pushes the rook’s pawn. White’s rook pawn. In the ordinary Bishop Exchange it goes on to 8e; here it stops on 8d for good. |
| 5 | ▲２五歩 2f2e | △８八角成 2b8h+ | Black pushes on to 2e. The trade, with Black’s bishop still at home on 8h. This is the lost move. |
| 7 | ▲同銀 7i8h | △２二銀 3a2b | The silver takes back from 7i and is developed in the same move. White’s left silver to 2b, on its way to 3c. |
| 9 | ▲７七銀 8h7g | △３二金 4a3b | Black’s silver to 7g: the Helmet Yagura’s silver. White’s left gold to 3b. |
| 11 | ▲７八金 6i7h | △３三銀 2b3c | Black’s left gold to 7h. The silver reaches 3c and covers 2d against Black’s rook pawn. |
| 13 | ▲３八銀 3i3h | △７二銀 7a7b | Black’s right silver up to 3h. White’s right silver up to 7b. |
| 15 | ▲９六歩 9g9f | △９四歩 9c9d | The edge pawns go up on both sides. |
| 17 | ▲１六歩 1g1f | △１四歩 1c1d | |
| 19 | ▲４六歩 4g4f | △６四歩 6c6d | Black opens the road for the right silver. |
| 21 | ▲４七銀 3h4g | △６三銀 7b6c | Black’s silver to 4g. White’s silver to 6c. |
| 23 | ▲５八金 4i5h | △５二金 6a5b | Black’s right gold to 5h. White’s right gold to 5b. |
| 25 | ▲６八玉 5i6h | △４二玉 5a4b | Black’s king steps to 6h. White’s king to 4b. |
| 27 | ▲７九玉 6h7i | △５四銀 6c5d | Black’s king goes on to 7i: Black’s Helmet Yagura, king 7i, golds 7h and 5h, silver 7g. White’s silver to 5d: a Reclining Silver. |
| 29 | ▲５六銀 4g5f | △３一玉 4b3a | And Black’s to 5f. Both sides now have a Reclining Silver. White’s king to 3a: the same castle turned round, king 3a, golds 3b and 5b, silver 3c. |
| 31 | ▲３六歩 3g3f | △４四歩 4c4d | White pushes 4d. |
| 33 | ▲６六歩 6g6f | △７四歩 7c7d | White pushes 7d, so that the knight can come to 7c. |
| 35 | ▲３七桂 2i3g | △７三桂 8a7c | Black’s knight to 3g. White’s knight to 7c, with 8e still empty in front of it. Both castles are complete; this is the position three sources draw. |
The plan once you are set up
- Open your bishop with 3d and take on 8h before Black has put the bishop on 7g. The line here does it on move 6; taking one move earlier, straight after Black’s 2f, also works.
- Bring the silver back to 2b and up to 3c, where it covers 2d against Black’s rook pawn.
- Leave the rook’s pawn on 8d. Castle with the king on 3a, and bring the right silver to 5d and the knight to 7c.
- When Black attacks the knight with a pawn on 7d, jump to 8e. In the ordinary Bishop Exchange, where your pawn already stands on 8e, a pawn dropped on 7d is bad news for White. shogi-rule.com, the source of this line, plays on past the point where the line here stops: Black opens the fight with the pawn to 4e, pushes on the edge and on the seventh and second files, and drops a pawn on 7d, and the knight jumps to 8e.
- Against the Rushing Silver, push the rook’s pawn to 8e after all and meet it with your own Reclining Silver, the setup that pairs well against it.
What to watch for
- The Rushing Silver (早繰り銀). Black puts the extra move into a fast silver to 4f and pawn to 3e, and the sources treat it as the main test. Aono Teruichi’s book on this opening gives it a whole chapter.
- The Climbing Silver. Black can go straight at your edge. Your pawn on 8d takes away one of Black’s follow-ups there, the bishop drop on 6f and the lance drop on 8d after the edge trade.
- A Right King (右玉). With the move in hand, Black can castle to the right with the edge pawn on 1e, and the sources say that plan suits Black better here than in the ordinary Bishop Exchange.
What it is played against
Black chooses how to use the extra move.
The three standard replies are the Reclining Silver, which leads to the line here; the Climbing Silver, the most direct way to punish the lost move; and the Rushing Silver, which Black turned to once the double Reclining Silver stopped giving an edge.
A quick knight attack (ポンポン桂) and the Right King are also played, and a Black Direct Opposing Rook has its own book line. By the sources’ account, none of them refutes the opening.
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.