Why Can't I Solve Tsume Shogi? Misreadings That Stop You at Mate in 3

The defending king is on 1一. You have a tokin (promoted pawn) on 1三 and a rook in hand. Drop the rook on 3一, ▲3一飛, and the king has no square to go to. The tokin covers 1二 and 2二, and the rook covers 2一. This is still not mate.

This article looks at ways of reading that stop you on a tsume shogi problem, one small position at a time. All the positions were made for this article, all are 3-move problems (your check, the reply, your mate), and every check and reply has been verified. If the notation is new to you, see How to Read Tsume Shogi Solutions. The method for solving is in Tsume Shogi for Beginners and the standard sacrifices are in Basic Tsume Shogi Tesuji. Here the focus is on the mistakes.

Taking “the king can’t move” for mate

Position 1: defender has king 1一. You have a tokin on 1三. In hand: a rook.

This is the opening position. After ▲3一飛, the defender can block on 2一, because there is one empty square between the rook and the king. In tsume shogi the defender holds every piece that is not on the board or in your hand, so a pawn, lance, knight, silver, gold, bishop or rook can all land there. If you capture with ▲同飛成 (the rook takes and promotes), nothing protects it on 2一, and the king takes back with △同玉. Whichever piece is dropped, there is no mate in 3. Dropping the rook further away, as in ▲4一飛, only adds more squares to block on.

The answer is ▲1二飛. The tokin protects the rook, so the king cannot take it, and with no square in between there is no block. The king has to go to 2一, and ▲2二飛成 is mate.

With a check from a distance, the king’s escape squares are only part of the reading. What can be dropped on the squares in between is part of it too. Blocks are covered in What Is Aigoma?

Forgetting what the moved piece was guarding

Position 2: defender has king 5一. You have gold 3二 and dragon (promoted rook) 6四. In hand: a silver.

Around the king, the gold covers 4一 and 4二, and the dragon covers 6一 and 6二. Only 5二 is open. So ▲5三龍 looks natural, because the dragon on 5三 covers 5二 as well.

But the dragon has left the 6-file. From 5三 it still reaches 6二, but not 6一. The king runs with △6一玉, and there is no mate in 3.

The answer is ▲6二銀. The dragon protects the silver, and the silver covers 6一. The king can only go to 5二, and then ▲5三龍 is mate. Once the silver has taken over 6一, the dragon is free to leave the file. The same ▲5三龍 becomes the mating move just by changing the order.

When you consider a check with a piece on the board, the squares it reaches from its new home are half the picture. The squares it guarded from the old one open up the moment it moves.

Dropping the strongest piece first

Position 3: defender has king 1二 and pawn 1四. You have bishop 2四. In hand: a gold and a silver.

The bishop covers 1三. After ▲1三金, the king cannot take the gold, and the gold also covers 2二 and 2三. That leaves 1一 and 2一. It is the stronger piece in hand, and it seems to take away the most squares. But it does not mate in 3.

The answer is the silver on the same square, ▲1三銀. A silver does not move sideways, so 2三 stays open. This check leaves the king more squares than the gold did.

• △1一玉 is met by ▲1二金
• △2一玉 is met by ▲2二金
• △2三玉 is met by ▲3三金

All three are mate. The silver protects the gold on 1二 or 2二, and the bishop protects the gold on 3三. In the △2三玉 line, the silver also protects the bishop on 2四, and the defender’s own pawn blocks 1四.

A gold kept in hand can cover many squares around the king with the last move. Mating shapes with a gold are in Basic Checkmate Shapes in Shogi. The piece to use first is not always the stronger one.

Reading only one reply

Back to ▲1三金 in Position 3. There are two replies, △1一玉 and △2一玉.

After △1一玉, ▲1二銀 is mate. The gold protects the silver in front of the king, the silver covers 2一, and the gold covers 2二. If you stop reading here, the problem looks solved.

After △2一玉 there is no mate. Drop the silver or move the gold, and the king is not caught on the next move. The defender picks the reply that does not lose.

The number of replies differs too. ▲1三金 allows two, and the correct ▲1三銀 allows three. The answer is not the check with the fewest replies. It is the check where every reply runs into a mate.

A reply can be a king move, a capture of the checking piece, or a block. All three kinds have to be looked at for each candidate check.

Not thinking about drops because your hand is empty

Position 4: defender has king 4一 and gold 5一. You have bishop 4二 and gold 4三. In hand: nothing.

With an empty hand, it is easy to think only of moving the pieces on the board. There are four checks: ▲3一角成, ▲5一角成, ▲3二金 and ▲5二金.

The answer is ▲5一角成. The bishop takes the gold on 5一 and promotes, so now there is a gold in your hand.

• △同玉 (the king takes) is met by ▲5二金打
• △3一玉 is met by ▲3二金打

打 marks a drop. Both are mate, with the gold on 4三 protecting the dropped gold. The diagram shows an empty hand, but by your second move there is a piece in it. A captured piece can be dropped on your very next move, so the hand has to be recounted whenever a line captures something.

Ignoring leftover pieces

The answers to Positions 1 to 4 all use up the pieces in hand. By tsume shogi convention, a problem whose main line (the line the composer intended) leaves pieces in hand counts as flawed. If you have read through the defender’s best replies, reached mate and still hold a piece, some reply or your first move may be misread. The convention is explained in The Finer Rules of Tsume Shogi.

When you are stuck

One way to get moving again is to run through these mistakes in order.

1. Have you listed every check, including checks with weak pieces, captures and moves without promoting?
2. For each check, have you looked at king moves, captures and blocks?
3. Does the piece you moved leave open a square it was guarding?
4. Have you added captured pieces to your hand?
5. When you reach mate, is anything left in hand?

Sometimes the mating shape on the last move is what you are not seeing yet. Should You Start with 1-Move Tsume? covers going back a step, and How Long Should You Think About a Tsume Shogi Problem Before Looking at the Answer? covers what to do when you keep reading the same moves.

Seeing misreadings 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 don’t look up the answer. You solve by playing on the board yourself. Any check, right or wrong, can be played, and the defender replies automatically. When your reading has gone wrong, the defender picks the escape that avoids mate, so where the king runs shows you the reply you missed. If you don’t mate within the move count, the attempt fails, and you can retry up to three times. After solving, Review lets you step back and forward 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.