Double Wing Attack, Floating Rook


In shogi, Floating Rook is a variation of the Double Wing Attack opening in which Black's rook falls back to rank 6 aiming to protect this rank and prevent White from exchanging pawns on the eighth file to get a pawn in hand.
The translated term floating is synonymous with the term hanging as in hanging piece used in western chess where floating means a piece that is not defended by another piece.
From this position, there are numerous subvariants.

Development

6. R-26. Floating Rook.
6....72 or 6....62. White has two options regarding their right silver: it could advance either to the seventh file or the sixth file. The seventh file option is more common and has become the standard move in Double Wing Attack while the sixth file option is an older move according to professional player Kiyokazu Katsumata.
6....72. Moving the silver up to the seventh file allows White the following possibilities:
However, this gives up defending 53 with the silver and moving to the central file via that square.
6....62. Moving the silver to the sixth file allows White the following possibilities:
However, the silver on 62 and the gold on 61 may form a wall blocking the king from escaping toward the right side of White's board if under attack. White can still attempt a Climbing Silver strategy although it will be a slower Oblique Climbing Silver strategy since White must move a pawn out of the way first.
Both moves allow for a Reclining Silver positioning of the silver on 54.
After move 22, Floating Rook Double Wing Attack branches off into several different substrategies, which are detailed below.

Sickle and Chain Silver

Sickle and Chain Silver or Chained Sickle Silver

Reclining Silver

In order to play Reclining Silver or Sitting Silver, Black must advance their right silver to the 56 square through 47 while White advances their silver to 54 through 63.
Since a pawn is blocking the path of the silver, it must be pushed forward first. White usually makes this pawn push earlier than Black's pawn push on the fourth file.
13....P-34. White activates their bishop by opening the bishop diagonal. It's possible that opening the diagonal could have been done sooner before moving the silvers and edge pawns.

Clanging Silvers

Clanging Silvers

Nakahara Floating Rook

Nakahara Double Wing Attack is a Floating Rook variant has Black advancing the third file pawn.
This allows a space on the 37 square for either the silver or the knight to move to.
White responds by activating their bishop.
These strategies are named after Makoto Nakahara.

Nakahara Silver-37

Nakahara's silver variant starts with a silver advanced on the third file.
White likewise advances their silver.
Black then aims for an attack on the third file.

Nakahara Knight-37

Nakahara's knight variant moves the knight to 37 instead of the silver.

Tsukada Special

Tsukada Special is a Floating Rook variant of the Double Wing Attack opening developed by professional Yasuaki Tsukada.

Rook on Pawn

Rook on Pawn is a subclass of Floating Rook openings in which the Floating Rook player moves their rook to the third file aiming to capture their opponent's pawn used to open their bishop diagonal at the 34 square.