Tsume · 2026-10-03
Mate in 9.
The tsume for 2026-10-03: black to play and checkmate in 9 plies. Every move must be check; the defender holds every piece not on the board or in black’s hand.
Black to play. Mate in 9.Problem eaf80016 · tap a piece, then a square; drops from the hand below the board.
Tsume rules. Every one of your moves must be check. The defender holds every piece that is not on the board or in your hand, and plays the toughest defence. Any mate that works in the stated number of moves counts, not only the recorded one.
About this problem. Difficulty dan. Play it above, or read the answer below.
The solution
▲G*2e △K-1f ▲G-2f △K-1g ▲G-2g △K-1h ▲G-2h △K-1i ▲G-2i
Read ▲ as black, △ as white; a move like G*5b is a drop, a plus sign a promotion.
What a tsume is
Tsume shogi (詰将棋) is the checkmate problem of shogi, with a tradition of its own: collections were being published in the 1600s, and the form has its own rules, composers and prizes. A problem gives you a position where black must checkmate white in a stated number of moves, and every black move must be check. White defends as stubbornly as possible, and holds every piece that is not on the board or in black’s hand to defend with. That last rule is what makes the genre: the defender can interpose anything, so a mate must be airtight.
The problems here come from the app’s library: composed problems from mate in one to mate in eleven, taken from an open collection (tanuki-tsume-shogi) and each one checked by the app’s mate solver for exactly one first move that works. The app’s puzzle ladder starts from these.
How to solve one
- Count the escape squares first. Where can the king go now? Your first move has to take those away or give check in a way that leaves them useless.
- Look for the pattern. Most short tsume end in one of the ten named shapes: a gold on the head, a dragon with one square between it and the king, a mate in the corner. Ask which shape the pieces you have can make.
- Try the sacrifice. In a problem, unlike a game, giving away a piece is usually the point. A drop next to the king that must be taken drags the king where you want it.
- Read the defender’s best reply, not the one you hope for. The board here plays the toughest defence it can find, so a line that only works against a cooperative king will be sent back.
Why one a day
A single problem, the same for everyone, changes at midnight UTC here on the site (the app turns over at your own midnight). Solve it, share it, come back tomorrow. The app has the rest: a ladder from mate in one upward, mates taken from real games at your rating, spaced review of the ones you missed, and a puzzle rating that follows your account.
More than one a day.
The app has the ladder, mates from real games at your rating, and a puzzle rating that follows your account.