Ishida.

Ranging rook · castles into Mino · 石田流 ishida-ryū

The idea

Named after a blind player of the seventeenth century, the Ishida is a ranging rook with a difference: instead of waiting, it attacks. The pawn goes to 7e early, the rook swings to 7h and then steps up to 7f, the knight jumps to 7g and the bishop comes round to 9g, so that rook, knight and bishop all look at the opponent’s left side.

The king castles into a Mino on the right as usual. It is fast, it is aggressive, and the shape is one of the prettiest in shogi; it is also one of the most popular ranging rooks (fourth in the 2019 『将棋戦法事典100+』 ranking).

How it goes together

The plan once you are set up

• Get the shape before the fight: pawn 7e, rook 7f, knight 7g, bishop 9g. Each piece protects the next.
• The attack is the 7e pawn: push it to 7d when the exchange favours you, and the rook and knight pour through.
• The bishop on 9g and the rook on 7f both watch 8f, and the knight on 7g already hits 8e. A pawn that pushes on to 8f is a target, not a threat.
• Keep the Mino honest: silver 3h and gold 5h before the attack starts, because an Ishida attack that fails leaves your king to face the music alone.

What to watch for

• The early bishop trade. If white can exchange bishops before your rook reaches 7f, the knight on 7g becomes a target for a dropped bishop.
• The 8e pawn push comes with a threat on 8f; answer it with the bishop or the knight in time.
• A quiet opponent who refuses to open anything. Then the Ishida turns into a normal ranging rook: finish the castle and wait.

What it is played against

A static rook, most often. Pushing 7e on move three and attacking at once, before the shape is built, is the Quick Ishida; the line above starts the same way and builds the full shape first.

Against the Anaguma: the Kusumoto Ishida

Kusumoto Ishida (楠本式石田流)

Against a Static Rook Anaguma, the amateur Kusumoto built the Ishida with the bishop on the other side.

Instead of 9g it goes round to 3g, after the pawn to 3f, where, as thirdfilerook.jp puts it, it aims at White’s rook and at the lance on 9a. ja.wikipedia gives the plan: the pawn to 7d at the weak diagonal beside White’s rook, the bishop promoting on 9a, and the horse brought back to 2h beside the king.

The king itself goes to the edge, 1h, and the edge pawn stays on 1g, because pushing it would invite an attack on that king. The boards are thirdfilerook.jp’s: before the bishop moves, and after the pawn to 3f, White’s rook to 8d and the bishop to 3g.

The site calls it a plan for the Anaguma only, because it takes many moves, and the two sources draw the finished castle differently, so no final position is shown. ja.wikipedia notes that one book collects its joseki with those of Masuda’s Ishida and the Tateishi Fourth File Rook.