Openings · 角換わり
Bishop Exchange.
Trade the bishops early, so both sides hold one in hand and every square one could be dropped on has to be watched.
The idea
This is not a system and it is not something you can play alone: the opening is defined by the bishop trade, and in the main line it is WHITE who takes. Your part is to invite it. The bishop steps up to 7g, the silver comes to 8h so the recapture is ready before it is needed, and the golds tidy up the squares a bishop in hand would love. After the trade both players hold a bishop, and that changes what counts as a weakness: an undefended square in your own camp is now a piece, and both sides spend the next ten moves making sure there are none. The king has not castled at the end of the line below, and the castle it is heading for is the 片矢倉, with the silver already on 7g and the gold on 7h.
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 | △８四歩 8c8d | |
| 3 | ▲２六歩 2g2f | △３二金 4a3b | |
| 5 | ▲７八金 6i7h | △８五歩 8d8e | And this gold guards the bishop’s head, which is the square everyone in this opening is thinking about. |
| 7 | ▲７七角 8h7g | △３四歩 3c3d | The bishop steps up. Now it can be taken. |
| 9 | ▲８八銀 7i8h | △７七角成 2b7g+ | The recapture, prepared a move before it is needed. This is what makes the whole thing safe. |
| 11 | ▲同銀 8h7g | △４二銀 3a4b | The silver takes it back. Both sides now hold a bishop in hand. |
| 13 | ▲３八銀 3i3h | △７二銀 7a7b | The right silver comes up, ready to go three different ways. |
The plan once you are set up
- Count the drop squares before every move. A bishop in hand punishes a gold that has left home and a silver that has not, and most early mistakes here are one careless move from a fork.
- Then choose an attack. There are three standard ones: the Climbing Silver up the rook’s file, the Rapid Silver to 4f and the Reclining Silver to 5f, and the whole opening turns on which of them the other side has prepared.
- Finish the castle. The 片矢倉 with the king on 8h is the natural home here, and it is what makes the middlegame trades safe.
- Do not drop your bishop early just to be doing something. A bishop in hand is worth more than a bishop on a square, right up until it wins something.
What to watch for
- The bishop’s head: 7g for you, 3c for them. Almost everything in this opening happens near those two squares.
- A gold moved one square too soon. In a game where both sides hold a bishop, that is not a slow move, it is a lost piece.
- Theory. This is the most heavily studied opening in professional shogi and it changes every year; what is above is the durable part, not a repertoire.
What it is played against
Another static rook, and it is the choice of most professionals when they want a fight. Against a ranging rook the bishops usually stay on the board and this opening does not arise.
Play it against the bot.
The app’s bot plays real openings from a book, and the review afterwards tells you the move you left it. Try the line, then try the plan.