Double Ranging Rook.

Ranging rook · castles into Gold Twins · 相振り飛車 aifuribisha

The idea

When both players swing the rook, both kings castle on the side their rooks left, and the attacks come straight down the files at the castles. The source describes it as once close to a second-class strategy, a free-for-all twenty years ago, that became organised as the openings developed and now appears in professional title games.

This page follows the line the source gives as the long-standing standard: Black plays the Opposing Rook and builds a Gold Twins, White plays the Third File Rook with a Mino. White pushes the third-file pawn to start a fight early; Black takes, drops a pawn back on 3g when the rook recaptures, and finishes the 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.

The plan once you are set up

• Castle for attacks from the front. Here the opponent’s rook stands right above your castle, which is why Black builds the Gold Twins, stronger from above than a Mino.
• Meet the early pawn push plainly: take, and when the rook takes back, drop a pawn in front of it. The line above does exactly that.
• Expect variety. The source names three castles in this opening, the Gold Twins, the Mino and the Yagura, and which pair you get depends on the other side.
• Your rook on the eighth file aims at the side of White’s castle, one file from the king on 7a.

What to watch for

• The third file: White’s rook is there, and it is where White starts the fight in this line.
• The side of the Gold Twins. It is weaker from the side than a Mino, so a rook that turns into your back rank is the danger.
• Theory is younger here: the source says there is still room for the openings to develop.

What it is played against

Only another ranging rook: it is what happens when both players swing, and the source says it can arise from how the opponent plays the opening.

A feint first

Feint Ranging Rook (陽動振り飛車)

A Feint Ranging Rook starts like a static rook game and swings the rook once the opponent has committed to a shape built for a static rook.

In the narrow sense ja.wikipedia gives, it is White’s: after Black’s 7f, White pushes the rook pawn to 8d, the static rook’s move; Black answers with the Yagura moves, the silver to 6h and 7g; and White swings the rook to 3b (the first board) or pushes the pawn to 3e first (the second).

A Yagura is weak from the side and Black has not pushed the rook pawn, so White can build an Ishida, and with the silver on 7g an Anaguma is harder for Black to build.

Katō Jirō named it. ja.wikipedia says knowing when to swing is hard, which is why it is rarely played now, and en.wikipedia notes that the castle is often a Top Knot Mino, with the pushed rook pawn left standing over the king. Shogi Wars adds the catch: the feinting side’s own position is limited too.

The sources give only these six moves, which is why this is a section rather than a page. The same idea works for Black: one English-language blog shows Black opening like a ranging rook, playing the rook pawn to 2f as if staying static, and swinging the rook to 8h once White has defended Yagura-style.