Composing Your Own Tsume Shogi: A Beginner's Method

The defending king is on 4二. You have a silver on 3二 and two golds in hand. This is the mate in 3 that this post ends with. There are two pieces on the board, and four counting the pieces in hand.

This post builds that problem from its final position, one step at a time. The positions were made for this post.

Squares are written the Japanese way: 4二 means file 4, rank 2, and rank 1 is the defender’s back rank. Moves marked ▲ are the attacker’s and △ the defender’s. If the notation is new to you, see How to Read Tsume Shogi Solutions.

The rules a composed problem keeps

Composed tsume shogi follows a few conventions so that a solver can check their answer. When composing, these four matter most.

• The attacker checks on every move, and the defender always picks the reply that lasts longest.
• There is no mating line other than the intended one, the sakui (作意). A second line is called a yozume (余詰), or a cook. A different final move alone is allowed.
• When the king is mated, the attacker has no pieces left in hand.
• No decorative pieces: nothing on the board that makes no difference to the problem.

The rules on leftover pieces and decorative pieces are also in the Japanese Wikipedia article on tsume shogi. They are explained in The Finer Rules of Tsume Shogi and What Is Yozume? One more point: the defender holds every piece that is not on the board or in the attacker’s hand, and can drop any of them to block.

Start from the mating position

One way to compose is to decide the final position first and work the moves backward.

The final position here is: king on 5一, your golds on 5二 and 4三.

The gold on 5二 covers 4一 and 6一 beside the king, and 4二 and 6二 diagonally in front. The gold on 4三 protects it, so the king cannot take it. The king is on the back rank, so it has nowhere to go behind. That is mate. It is the “gold on the head” shape from Basic Checkmate Shapes in Shogi, with the gold on 4三 as the protector.

One move back: a mate in 1

Put the last gold back in hand. King on 5一, your gold on 4三, a gold in hand.

The answer is ▲5二金打 (gold drop on 5二). There are 7 checks in this position, and this is the only one that mates. Moving the gold from 4三 to 5二 is also check, but nothing protects it there, and △同玉 (the king takes) follows. Because the gold on the board can also reach 5二, the solution adds 打 to show that the gold comes from your hand.

Another move back: where did the king come from?

Next, the position before the king reached 5一. Say the king ran there to escape a check, and that check was a gold dropped on 4三. Put the king on 4二 and the 4三 gold back in hand: king on 4二, two golds in hand.

As it stands, ▲4三金 is met by △同玉. Nothing protects the gold.

A gold dropped on 4三 covers 3二, 5二, 3三 and 5三. That leaves 3一, 4一 and 5一 open. In the intended line the king should go to 5一, so you add a piece that does three things.

• Protects the gold on 4三.
• Covers 3一 and 4一.
• Leaves 5一 open.

A dragon brings a cook

If all you want is to protect 4三, a dragon (promoted rook) on 2三 does it along the third rank. King on 4二, your dragon on 2三, two golds in hand.

This position does mate in 3 starting with ▲4三金. But ▲5三金 also mates in 3. The dragon protects 5三 too, through 3三 and 4三. Wherever the king goes, 3一, 4一 or 5一, the next gold drop mates.

Two first moves, both mating in 3: that is a cook, and the problem is unsound as it stands. Here the dragon covered so much that a second way to mate appeared.

Rebuild with a silver

Instead of the dragon, put a silver on 3二.

A silver covers 3一 straight ahead and 4一 diagonally ahead. It also covers 4三 diagonally behind, so it protects a gold dropped there. One piece meets all three conditions. The silver sits right next to the king, but once the gold is on 4三, the gold protects 3二 and the king cannot take the silver.

That gives the position from the start of this post.

Problem: defender has king 4二. You have silver 3二. In hand: two golds. Mate in 3.

The answer is ▲4三金 △5一玉 ▲5二金打.

Check every first move

Once the problem is made, switch sides and list every check on move 1. There are 9.

• Four move the silver: ▲3一銀, ▲4一銀成, ▲4三銀 and ▲4三銀成. The two moves to 4三 leave the silver unprotected, and △同玉 takes it. After ▲3一銀 or ▲4一銀成, the king escapes to squares such as 3二, which the silver has left.
• Five drop a gold: ▲3三金, ▲4一金, ▲4三金, ▲5二金 and ▲5三金. The silver protects only 4一 and 4三, so ▲3三金, ▲5二金 and ▲5三金 are simply taken. After ▲4一金, the gold on 4一 does not protect the silver on 3二, and △3二玉 takes the silver.

Only ▲4三金 mates. There is no cook on the first move.

Check every defence

Now list every reply to ▲4三金.

• △同玉 is not possible, because the silver protects the gold.
• △3一玉 and △4一玉 are covered by the silver.
• 3二, 5二, 3三 and 5三 are covered by the gold. Taking the silver on 3二 is not possible either, because the gold protects it.

The only escape is △5一玉. The check comes from an adjacent gold, so there is nothing to block.

After △5一玉, ▲5二金打 is the only mate. Moving the 4三 gold to 5二 leaves it unprotected, and the king takes it. The last move is unique too.

Check leftover and decorative pieces

At the end, both golds from your hand are on the board. Nothing is left over.

Last, remove each piece in turn. Without the silver on 3二, ▲4三金 is met by △同玉 and there is no mate in 3. With only one gold in hand there is no mate either. Every piece has a job, so none is decorative.

The steps in order

Put together, the method runs like this.

1. Decide the mating position.
2. Put the last move back in hand to make a mate in 1.
3. Decide where the king came from and go back one more move. Add a piece to cover the escape squares.
4. List every first check and see whether anything other than the intended move mates.
5. List every defence and see whether each one is mated.
6. Check that no piece is left in hand and that no piece can be removed without changing the problem.

To make a mate in 5, you decide where the king came from again and go back two more moves. The longer the problem, the more moves there are to list in steps 4 and 5.

Solving tsume shogi in Shogi365

Shogi365 contains tsume shogi from mate in 3 to mate in 9, with 1,000 problems for each length, 4,000 in total. You choose by length.

You solve by playing on the board yourself. Any check, right or wrong, can be played, and the defender replies automatically. If you don’t mate within the move count, the attempt fails, and you can retry up to three times. After solving, the Review button steps through the line from the start position one move at a time.

All problems are free to solve. The app shows ads, and a one-time Remove Ads purchase turns them off. How to use the app is in Getting Started with Shogi365.