Silver Horns Central Rook.

Ranging rook, played by White · castles into Kimura Mino, on White’s side · ツノ銀中飛車 tsuno-gin nakabisha

The idea

This line is White’s. The Silver Horns Central Rook is the classical Central Rook: the bishop’s diagonal is closed, the rook goes to 5b, the left silver comes up to 4c, and against a slow game the right silver comes to 6c, so the two silvers stand either side of the centre file like a pair of horns.

Because the rook stands on the file where a gold would usually go, the king castles into a Kimura Mino, king 8b, gold 7b and silver 6c, and the other gold stays on 3b. Shogi Wars describes it as taking the opponent’s attack head-on.

Ōyama Yasuharu played it through title matches, sliding his left gold and silver over to the king during the fight. ja.wikipedia says it declined because it had no answer to the Static Rook Anaguma.

The line follows 将棋の戦法図鑑, the one source with every move: Black tries a rapid attack with the left silver on 5g and then a Climbing Silver, and White breaks with the pawn to 4e as the silver arrives on 2f. That source calls the finished position the easier game for White. Two later forms, the Pinwheel and the Hide-chan Central Rook, are sections of the Central Rook page.

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

• After Black’s 7f and 2f, close the diagonal with the pawn to 4d.
• Left silver to 4b and 4c, centre pawn to 5d, rook to 5b.
• King to 6b, 7b and 8b; the right silver to 7b and the left gold to 3b.
• Drop the rook back to the bottom rank when the fight is coming, and strike in the centre when Black’s attack arrives.
• Complete the second horn with the pawn to 6d and the silver to 6c, then bring the gold to 7b, beside the king, where the silver guards it: the Kimura Mino.

What to watch for

• The Climbing Silver. Strike with the pawn to 4e at the moment the silver reaches 2f, then open the centre with the pawn to 5e. Both the source of this line and Katō Hifumi, in a book ja.wikipedia cites, say the Climbing Silver does not work well against it.
• The rook pawn exchange. In the source’s next diagram, Black’s pawn to 2d is answered with a bishop dropped on 1e and the rook to 2a, and Black is close to lost.
• The thin king. ja.wikipedia: the generals are split left and right, with only one gold and one silver beside the king, which makes the opening hard to handle. Against a Static Rook Anaguma there is no decisive plan.

What it is played against

A static rook. ja.wikipedia lists what works against it: rapid attacks are very hard, though Katō’s Sleeve Rook and the Standing Gold are known answers to White’s Central Rook; in slow games, the Static Rook Anaguma and the King’s Head Vanguard Pawn.

The rapid attack shown here, the left silver on 5g and then a Climbing Silver, turns out well for White.