Third File Rook.

Ranging rook · castles into Mino · 三間飛車 sangenbisha

The idea

The Fourth File Rook’s quieter neighbour, and the difference is one file. The rook goes to the third file counting from the left, which puts it directly behind its own pawn, so pushing that pawn to 7e is an attack rather than a formality, and if you keep pushing you are in the Ishida, which is why the two are usually learned together.

The move that looks spare is not: once the rook has left its home square the head of the bishop is the weakest point in the position, and 7g is what covers it. The silver then takes the long way round by 6h, because the square it would normally use belongs to the rook.

How it goes together

Only Black’s moves are shown. This is a build order rather than a game: the opponent is left standing still, because a reply on every move would hide the shape instead of explaining it. Every move was still played through the engine, so the position is one the rules allow.

The plan once you are set up

• Push the pawn to 7e once the castle is finished. That is the whole reason the rook stands where it does, and it is the move that turns this into a real attack.
• If the pawn exchange comes off, lift the rook to 7f in front of it. That is the Ishida shape, and the knight on 7g and the bishop on 9g are the follow-up.
• Against a static rook attacking down the eighth file, the bishop on 7g is the defender. Keep it there and keep 6f closed until you want the trade.
• The Mino comes first. Silver 3h and gold 5h before any pawn goes forward, because a ranging rook attack that fails leaves the king to answer on its own.

What to watch for

• The bishop’s head. It is why 7g is played early, and moving the bishop somewhere else without a plan for 8f is the usual way to lose quickly.
• A quick push in the centre while you are still walking the king. Stop castling and answer it.
• An Anaguma. Waiting stops working against a king in the corner, so push 7e and make something happen before the door shuts.

What it is played against

Either family. Most often a static rook, where the 7e push and the eighth file both matter; it is also one of the best answers to another ranging rook, because the rook is already on the side that game is fought on.

Three plans against the Static Rook Anaguma

Three named Third File Rook plans are aimed at one opponent, the Static Rook Anaguma. The sources draw them as positions and give no order from move one, so they are shown here as positions, with the moves the sources give from them.

Manabe variation (真部流)

Against a static rook that digs into a four-piece Anaguma, the Manabe variation does not try to stop the castle.

Black builds a High Mino, then takes space on the fourth file: the left silver goes to 5g, the pawn to 4e, and the silver up to 4f, in front of the gold on 4g. ja.wikipedia’s point is that the four-piece Anaguma has pulled White’s right silver into the castle and left the centre thin, so Black plays there, with the pawn to 5e, rather than on the edge.

It is named after Manabe Kazuo, who often played it. thirdfilerook.jp warns that it works only if White chooses the four-piece Anaguma: against a quick silver on 6d there is no time to build it. The same site quotes Nakata Isao saying that White players no longer build that Anaguma, which is why the formation is rarely seen now.

Nakata XP (中田功XP)

Against a Static Rook Anaguma, Nakata Isao kept the king on 3i instead of building a Mino, pushed the edge pawn to 1f early, and readied the knight on 3g and the left silver on 5g. ja.wikipedia’s summary: the moves a Mino would cost go into an attack on the Anaguma’s edge with pawn, knight and bishop, and Black’s own king stays away from the edge being opened.

Shima Akira named it Nakata XP in his 2002 book, when Windows XP was new; most players call Nakata’s Third File Rook the Kōyan style, after his nickname. The first board is thirdfilerook.jp’s position at move 31, against a White Anaguma with the silver on 6d and the bishop on 3c.

White attacks first with the pawn to 7e; Black jumps the knight to 4e, at the bishop; after the bishop drops back to 4b, Black opens its own bishop’s line with the pawn to 6e, and when White’s silver takes it, the rook swings to 6h at the silver (the second board). thirdfilerook.jp judges the result good for Black.

The site gives four White setups and a different answer to each; this is the one both sources give in moves.

Tomahawk (トマホーク)

The Tomahawk attacks a Static Rook Anaguma that has left its fifth-file pawn at home. Black keeps the king on 4h instead of castling and takes the left silver from 6g through 5f to 4e; once White has guarded the pawn on 3d with the rook on 8d (the first board), the right knight jumps out from the edge, to 1g and then 2e.

The pawn to 6e then opens the bishop’s line toward White’s king (the second board), and the break comes with the knight jumping in on 1c and promoting. Between the two boards White has also played the gold to 3b and the bishop to 2d; thirdfilerook.jp, which draws both boards, does not say in which order.

The amateur Tap Dice spread the opening through his e-books, and it reached professionals after Yamamoto Hiroshi beat Fujii Sōta with it in 2016, in the league of the apprentice professionals. thirdfilerook.jp says it changed how professionals build the Anaguma: many now push the fifth-file pawn first, the “tax” the Tomahawk charges.