Yamada Joseki.

Static rook, a rapid attack on a ranging rook · castles into Boat · 山田定跡 Yamada jōseki

The idea

Yamada Michiyoshi’s answer to Ōyama Yasuharu’s Fourth File Rook, published from 1957. It starts from the same Left Silver-57 position as the Left Silver-46, but White’s silver has stayed on 3b and White waits with the 6d pawn.

Then the order matters: the silver to 4f first runs into White’s 4e, so Black pushes the third-file pawn first, lets White take, and only then brings the silver to 4f.

White’s pawn goes on to 3f, a move ja.wikipedia credits with three purposes at once; the silver steps on to 3e, and when White strikes with 4e, Black trades bishops on 3c at once, before White can take on 8h and pull Black’s king out. It cannot be played as White: a Black Fourth File Rook has pushed both its fifth and sixth-file pawns by then.

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

• Build the Boat and the Left Silver-57 position, as in the Left Silver-46.
• When White keeps the silver on 3b and waits with 6d, push 3e first and let White take.
• Bring the silver to 4f and, after White’s pawn goes on to 3f, step it to 3e.
• When White plays 4e, trade bishops on 3c at once.

What to watch for

• The order of the third-file push. The silver to 4f before the push is met by 4e.
• White’s waiting move. Yamada’s line answers the 6d pawn; the Saginomiya Joseki is the other way to play against a silver kept on 3b.
• The difference in castles: ja.wikipedia says that even a position slightly better for the static rook is hard to win in practice, because White’s Mino is the stronger castle.

What it is played against

A Fourth File Rook with a Mino whose silver stays on 3b, waiting with the 6d pawn. ja.wikipedia records that White’s silver to 4c came back into fashion after this joseki, which is where the Left Silver-46 comes in.