Yonenaga King.

How it goes together

Start from a Four-Piece Mino: king 8g, silvers 7g and 7h, golds 6g and 6i, bishop 7i. The king steps diagonally back to 9h, above the lance. The 7h silver climbs into the 8g square he left and becomes a crown, and the 6i gold comes up to 7h underneath it. The 7h gold now guards both silvers, the 6g gold and the bishop, and both silvers guard the 8f pawn in front of the crown.

This Yonenaga King is a Four-Piece Mino with three more moves: the first sixteen below are that castle.

Move by move

Black only, from the start position, as the Japan Shogi Association’s column builds it: the Tenshukaku Mino, five moves to the Four-Piece Mino, then the king, the silver and the gold.

Nineteen moves. The JSA column calls the result a Silver Crown of four generals with the king already out of the way of an attack on his head, a shape that leaves nothing to worry about.

What it is good against

An early escape. On 9h the king is off the long diagonal. ja.wikipedia says the idea is to gain time for the endgame race, and that a king moved there early very often ends up where it cannot be mated (ゼット). It adds that the edge looks weak, but the 8g silver makes that a small fault.

Where it breaks

Time, the lance and the side. It takes nineteen moves, and the JSA column notes that the opponent often stops the Four-Piece Mino on the way with a pawn to 6e. The king stands on his own lance, so the lance no longer defends, and ja.wikipedia says the side is not especially strong. On the bottom rank nothing guards 6i.

When to build it

A static rook against a ranging rook in a slow game. ja.wikipedia says the idea came from Yonenaga’s games against Ōyama Yasuharu and won him the Masuda Award announced in 2000, and that the name now mostly means the king placed above the lance (9h, or 1b for White) in any Silver Crown family castle; the three-general Edge King Silver Crown carries it too. The New Yonenaga King (新米長玉), in the section below, is something else: Yonenaga’s king to 6b on move two against the program Bonkras in 2012.

Against computers

Yonenaga’s name is also on a move he played against a program, and Shogi Wars awards it beside a formation built only to beat programs. Neither has anything to do with the castle above.

New Yonenaga King (新米長玉)

In the first Denou-sen, on 14 January 2012, Yonenaga Kunio played the program Bonkras and answered the pawn to 7f with the king to 6b on move two. He named the move the New Yonenaga King himself.

Bonanza’s author, Hoki Kunihiro, had suggested it as a way to take a Bonanza-type program out of its opening data, and after more than a hundred practice games Yonenaga held it to be the best reply against Bonkras. He built a solid position early, but the program won after one slip in the middlegame.

Shogi Wars still awards it as an item, and one guide says it no longer works against modern engines, which build their own opening knowledge. Yonenaga had used the same name in 1983, for a king on 3c.

Inaniwa (稲庭戦法)

Inaniwa is not meant for human opponents. The player never pushes a pawn, builds a flat wall behind them, the king on 7h, the golds on 9h and 3h, the silvers on 6h and 2h, the bishop on 7i and the rook on 5i or 4i, and then moves a gold or the rook back and forth, waiting for a program to lose on time.

Shogi Wars traces the idea to a computer game in 1997; ja.wikipedia describes the Maruyama Special it grew from, and the program Inaniwa Shogi, which went unbeaten through the first preliminary of the 2010 World Computer Shogi Championship, where games had sudden-death time limits. ja.wikipedia notes that a human can break the formation: it worked only against programs that could not find the way in.

The board is the shape Shogi Wars checks for, as one blog draws it; no source gives an order for it.