Yagura Central Rook.

Static rook, played by White · no castle (the king stays thin) · 矢倉中飛車 yagura nakabisha

The idea

This line is White’s, and it is not the ranging rook Central Rook named after Yagura Norihiro: here the rook goes to the centre inside a Double Yagura. ja.wikipedia calls it the main White rapid attack of the late 1980s and says leading players took it up again in the mid-1990s.

You push the pawn to 6d with the silver behind it on 6c, swing the rook to 5b, and trade the 5th-file pawn; when Black drops a pawn back on 5f, the rook goes back to 5a. The silver settles on 5d, the knight comes to 7c, and with a pawn in hand you break with the pawn to 6e.

It works best against a Yagura whose left silver has already reached 7g, because that silver then has to go back to 6h to defend the centre. That is why, the source says, Black’s fifth move in the Yagura changed from the silver to 7g to the pawn to 6f.

Black’s defence in this line, the bishop kept on 8h, the right silver on 5g and the left silver pulled back to 6h, is Tanaka Torahiko’s, once thought to hold. The whole order has one source, which calls the attack against it unexpectedly hard to meet.

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 loosely with the king on 4a, then 3a; push the pawn to 6d and bring the right silver to 6c.
• Swing the rook to 5b.
• Trade the 5th-file pawn and pull the rook back to 5a.
• Put the silver on 5d, jump the knight to 7c and bring the other gold to 6b.
• Break with the pawn to 6e, trade bishops on 8h, and use the pawns in hand on the 5th and 6th files.

What to watch for

• Black’s defence with the bishop kept on 8h, the right silver on 5g and the left silver pulled back to 6h. It was once thought to hold; the source’s attack against it starts with the pawn to 6e and the bishop trade.
• Your king. Like every Rapid Attack Yagura, it is thin, and Black’s counterattack comes fast once the attack stalls.
• Black’s fifth move. ja.wikipedia says the attack loses much of its force against the pawn to 6f on move five, with the silver still on 6h.
• The other plan. With a gold on 5b, the rook can go to 6a instead, which makes a Right Fourth File Rook setup.

What it is played against

Black keeps the bishop on 8h for defence, moves the right silver to 5g and pulls the silver on 7g back to 6h, a formation Izumi Masaki named the Roast Beef Sandwich.

Since about 2010 Black has often waited with the silver on 6h, playing it to 7g only after you commit with a gold to 5b.