Left Silver-5g Rapid Attack

Left Silver-5g Rapid Attack or Left Silver-5g Quick Attack (5七銀左急戦 go-nana gin hidari kyuusen) is a fast attacking strategy in shogi used with several different Static Rook (居飛車) openings often played by Black (先手) against Ranging Rook (振り飛車) positions played by White (後手). It is characterized by moving the left silver (銀) from its start position on 7i to the 5g square.

The Static Rook position is usually combined with a Boat castle (船囲い).

When Left Silver-5g Rapid Attack is used against a Fourth File Rook opponent, Left Silver-5g Rapid Attack often transitions to the Left Silver-4f^[] (4六銀左 yon-roku gin hidari) class of openings.

The Left Silver-5g Rapid Attack openings against Fourth File Rook include the Yamada joseki (山田定跡 yamada jouseki), the Saginomiya joseki (鷺宮定跡 saginomiya jouseki), and Pawn-4e Quick Fight^[] or Pawn-4e Rapid Engage (4五歩早仕掛け yon-go fu haya-shikake) among others.

The opening starts by the usual Static Rook vs Ranging Rook four-move sequence that results in the board position shown on the right. (See: Traditional Ranging Rook.)

After the fourth move, the position can proceed in a number of different ways. The subsequent moves can be categorized with the following components:

These components can be used in different orders and even with some interleaving between them. Additionally, there may also be some strategic keeping the true intentions behind each player's moves uncertain in the hopes that an opponent will not respond with adequate defensive measures.

If Black is truly going for a rapid attack, then they will build a Boat castle since that can be created with relatively few moves. Black later may have an option on converting the Boat castle in the stronger Static Rook Anaguma (居飛車穴熊) or Left Mino (左美濃) and possibly further into the Left Silver Crown (左銀冠). White often builds either a Mino castle (美濃囲い) or an Ranging Rook Anaguma (振り飛車穴熊).

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Wikipedia