Meet the subject
詰将棋
Tsume-shōgi is a composed shogi mating problem. The attacker checks continuously and the defender resists as strongly as possible. A solution must account for every legal defense, using the position, pieces in hand and movement rules together.
Three plies count attacker, defender and attacker.
Check differs from mate: king moves, captures and blocks must all be considered.
Different defensive branches can require different final moves.
Tsume-shōgi is a composed mating problem. The attacker gives check on every move, while the defender chooses the best resistance and longest survival. A three-ply problem counts attacker, defender and attacker as its three moves.
Check means that the king is attacked. Mate requires every legal answer to fail: moving the king, capturing the checking piece or blocking its attack. Solving a problem involves checking all the defender’s legal replies.
| Defense | What to check |
|---|---|
| King move | Is the destination attacked? |
| Capture checking piece | Is the king still attacked? |
| Interpose | Can a piece cut the attacking line? |
In shogi, captured pieces become pieces in hand and can be dropped onto the board. The attacker has only the hand specified by the problem. All otherwise unassigned pieces except a king are treated as the defender’s hand and may be used for legal defense.
A pawn cannot be dropped into a file already containing another unpromoted friendly pawn. Pieces cannot be moved or dropped where they would have no legal move afterward. Dropping a pawn to give immediate mate is prohibited, unlike mating by moving a pawn already on the board. The defender does not make futile interpositions that can simply be taken without changing the mating sequence.
The example uses a rook, bishop, gold, silver and king. A rook moves along ranks and files; a bishop moves diagonally, neither jumping pieces. A promoted bishop, called a horse, keeps its diagonal movement and gains a one-square orthogonal move. The king moves one square in any direction; gold and silver use specified neighboring squares.
Attacker’s view, forward up. ● One square; arrows continue along the direction without jumping pieces.
In file-and-rank notation, the attacker has a rook on 5-2, a bishop on 5-3 and a gold in hand. The defender has a king on 2-1 and silver on 2-2. The attacker moves forward toward rank 1. A gold moves one square forward, forward-diagonally, sideways or straight back. The defending silver faces the opposite way and moves to its three forward neighbors or two backward diagonals.
Attacker’s hand: one gold
The bishop travels diagonally from 5-3 through 4-2 to 3-1 and promotes to a horse. Its new one-square sideways move attacks the king on 2-1. Since the horse and king are adjacent, a dropped blocking piece cannot go between them.
The following views show the upper-right part of the 9×9 board, retaining its global coordinates.
Red line: check. Blue line: rook protection or control. Orange dots: controlled king escapes. Grey dashes: the bishop’s first move.
The horse on 3-1 checks the king on 2-1 directly. The rook on 5-2 controls 3-2 through 4-2, but its ray stops at the defending silver on 2-2.
Attacker’s hand: one gold
In the main line, the king captures the horse on 3-1, followed by a gold drop on 3-2. The gold checks and covers the relevant neighboring escapes. The rook on 5-2 protects the gold through the empty 4-2 square, so capturing it is also unavailable to the king.
Gold on 3-2 checks the king on 3-1 and is protected by rook 5-2 through 4-2. Gold covers 2-1, 4-1 and 4-2; 2-2 holds the king’s own silver, while the protected gold bars capture on 3-2.
Attacker’s hand: none
The silver on 2-2 can instead capture the horse on 3-1, leaving the king on 2-1. A gold dropped on 1-2 checks diagonally forward. The rook protects the gold along rank 2, and the gold covers the remaining neighboring escapes: mate.
Gold 1-2 checks king 2-1. Once the silver leaves 2-2, rook 5-2 protects the gold through 4-2, 3-2 and 2-2. Gold covers 1-1, the rook covers 3-2, and the king’s silver occupies 3-1.
Attacker’s hand: none
The king can also move from 2-1 to 1-1 or 1-2. In either case, the horse captures the silver on 2-2. Protected by the rook, it checks and covers the adjacent escapes. These two branches end in mate while the gold remains in hand.
Horse 2-2 checks king 1-1 diagonally and controls 1-2 and 2-1. Rook 5-2 protects the horse through 4-2 and 3-2. The attacker keeps the gold in hand and gains the captured silver.
Attacker’s hand: one gold and one silver
Horse 2-2 checks king 1-2 horizontally and covers 1-1, 1-3, 2-1 and 2-3. Rook 5-2 protects it through 4-2 and 3-2. The attacker has both gold and silver in hand.
Attacker’s hand: one gold and one silver
Presentation of diagram collections to the shogunate formed part of Edo-period shogi culture. The catalogue for Itō Kanju’s Shōgi hyakuban kikō zushiki records a 1755 postface. Such collections preserve carefully arranged positions as works to study repeatedly.
The catalogue for Tsume Shogi Paradise begins in 1950 and records a monthly magazine, with interruptions and renumbering. Osaka Prefectural Library discusses Kurokawa Ichirō’s 1954 Rakka smoke-mate composition and a 1975 collection with Kadowaki Yoshio’s commentary on classical problems. New compositions and annotated older works offered different ways to study.
National Diet Library; 209-461, digital item 861211, scan 5.
The Japan Shogi Association now publishes daily problems and move records. This three-ply example has four legal defensive replies after the first move. Following each to mate explains why the opening move works and how different branches can use the hand differently.
| Reply after the first check | Mating answer |
|---|---|
| K2-1×3-1 | Gold drop 3-2 |
| S2-2×3-1 | Gold drop 1-2 |
| K2-1→1-1 | Horse 3-1 × 2-2 |
| K2-1→1-2 | Horse 3-1 × 2-2 |
The attacker’s first move, the defender’s reply and the attacker’s mating move.
No. The attacker must give check on every move.
The horse on 3-1 is adjacent to the king on 2-1, leaving no intervening square.
No. If the king moves to 1-1 or 1-2, the horse captures the silver on 2-2 and mates with the gold still in hand.