However, a Static Rook strategy – the King's Head Vanguard Pawn – became a formidable challenge to Ranging Rook positions, as the Mino castle is weak against frontal attacks and the King's Head Vanguard Pawn strategy exploits these weaknesses by attacking the Mino from above.
[a] Therefore, a change from a Mino to a Bear-in-the-hole was considered since the Ranging Rook player's king is moved one rank further away from the vanguard pawn offense.
[3] The adjacent diagram shows Tanaka (Black) using Static Rook position with an Incomplete Bear-in-the-hole castle in an October 1976 professional match.
According to retired professional Noboru Tamaru (田丸昇), an amateur player who had used the Static Rook Bear-in-the-hole in the 1970s brought a lawsuit against Tanaka for Tanaka's alleged false claims.
The end result will place the king in the corner square where the lance started, defended by two gold generals and one silver.
When the king is positioned at the corner square, if there were only the knight and the lance with no generals, there would be a hole diagonally in front of the king – the 88 (Black) or 22 (White) square for Ranging Rook Bear-in-the-hole and the 28 (Black) or 82 (White) squares for Static Rook Bear-in-the-hole.
A Rook at the back row of the board places notable pressure on the bottom pieces of Anaguma Castles, and very few pieces can move without reducing the strength of the castle and allowing a strong attack.