This mate-in-one teaches Head Gold (atama-kin), a recurring finish in which a Gold is placed directly in front of the enemy King. Sente is the attacker.
Problem
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Gold drop on 5b. The Gold checks the King on 5a. The Sente Silver on 4c protects 5b, so the King cannot capture the checking Gold. The Gold controls 4a and 6a, and the board edge removes any rank above a. No legal escape remains.
Verification Checklist
- The move gives check immediately.
- The checking Gold is protected by the Silver.
- The King cannot capture the Gold or move to 4a or 6a.
- The move is a Gold drop, so the Pawn-drop-mate restriction does not apply.
Pattern, Not a Magic Square
Head Gold means the relationship between the Gold and King, not always square 5b. In another position the same pattern may appear on a different file or from Gote’s perspective. Confirm protection and escape squares every time.
Next, solve the additional positions in the Tsume Shogi guide, then compare mate threats in the endgame lesson.
Prove the Mate in Four Checks
- Check: the Gold dropped on 5b attacks the King on 5a.
- Capture: the King cannot capture 5b because the Silver on 4c protects that square.
- Escapes: the Gold controls 4a and 6a, while the board edge removes squares beyond rank a.
- Interposition: the Gold checks from an adjacent square, so there is no square between the Gold and King on which to block.
Why the Starting Position Matters
The supporting Silver protects 5b without already checking the King on 5a. That distinction is essential: Sente must make a checking move as the first move of this mate-in-one. A support piece placed on the fifth file could accidentally give check before the solution begins and would make this teaching position unsuitable.
Wrong Ideas to Reject
| Idea | Why it is incomplete |
|---|---|
| Drop the Gold near the King. | Near is not enough; the move must check and cover every escape. |
| Count only King moves. | Always test captures and blocks when the checking geometry permits them. |
| Assume a named pattern always mates. | Head Gold works only when the Gold is protected and all escapes are covered. |
For an independent board audit, turn on coordinates and legal-move highlighting. Inspect the Silver on 4c before making the drop, then solve with the Gold on 5b. After the correct result, reset the board and account separately for 4a, 5b, and 6a. This prevents the pattern name from replacing square-by-square proof.
Official Rule Basis
The Japan Shogi Association tsume rules require the attacker to check, the defender to answer the check and resist for the longest valid line, and all ordinary shogi restrictions to remain in force. The general definition of mate and legal movement is also checked against the current Japan Shogi Association playing rules.
