Chain (Mind Loft)
Find the one edge that keeps a won dots and boxes ending.
Every day: One dots and boxes endgame a day, the same for every player: a real position where the safe edges are gone, you are ahead on boxes, and exactly one edge keeps the win against a perfect engine. New puzzle: Midnight US Eastern Time.

Chain is Mind Loft's daily dots and boxes endgame. Each day brings a real position in which the safe moves have run out and you are winning on boxes; draw the one edge that keeps the win, then play it out against a perfect engine with no take-backs.
About Chain (Mind Loft)
Chain takes the pencil game of dots and boxes, where you join two dots and close a box to move again, and gives you only its ending. By the time the board reaches you, every safe edge is gone, so any line you draw opens a chain of boxes for the other side. The question is who runs out of quiet moves first.
That is why grabbing every box on offer can lose. Sometimes the right play is to take most of a chain and hand the last two boxes back, keeping your opponent on move; sometimes that is exactly the mistake. The day's board is checked so that exactly one edge still wins, and the engine you play against does not make errors. There is a hint button, but no take-back: every edge you draw stands.
The header shows the date, your time and the box count, and a leader line shows the fastest player so far. Past boards stay in the Mind Loft archive with each day's standings, and Sundays bring a larger or harder Sunday Edition.
Chain is one of about a hundred free daily puzzles on Mind Loft, alongside other endgames such as Four (connect four), Mate and Defend (chess), Check (checkers), Turn (Othello) and Yose (go). It needs no account.
How to play Chain (Mind Loft)
- Open today's Chain and press Start.
- Study the board: the safe edges are gone and you lead on boxes.
- Draw an edge by tapping between two dots; closing a box gives you another move.
- Decide whether to take every box in a chain or hand the last two back to keep control.
- Keep the lead to the end against the engine; there is no take-back.
Screenshots

Tips
- Count the chains and loops before you move: the player who has to open the last long chain usually loses.
- Handing back two boxes at the end of a chain (a double-cross) keeps you in control when more chains remain.
- Open the shortest chain first when you have to give something away.
- Use Hint only once you have a candidate; the puzzle rewards the reasoning, and the clock keeps running.
Questions
When does a new Chain come out?
Every day at midnight US Eastern time. Sundays bring a bigger or harder Sunday Edition.
Is Chain the same for everyone?
Yes. Every player gets the same board, which is what the daily leaderboard ranks.
Can I undo a move?
No. Every edge you draw is played.
Is it free?
Yes, in the browser with no account. A display name puts your time on the leaderboard.
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