Hints, undo and spare bolts
Understand what each recovery control changes and why a hint may take time.
Ask for a hint
Hint suggests a source bolt and destination. It selects the source nut and shows the proposed move in the status line; you still choose the destination yourself. At the untouched starting board, the game can use its recorded solution. After your moves, a background worker searches the current arrangement.
Why a hint can be unavailable
The search has a time and state limit so it does not hold the page indefinitely. A message saying no route was found means the bounded search did not find one, rather than proof that the puzzle is impossible. Undo, an extra bolt or Restart are useful alternatives. The search is cancelled when you change the board.
Choose the recovery you need
| Control | What changes |
|---|---|
| Undo | Restores the previous arrangement for this session and reduces the move count. |
| Restart | Restores the original board, clears session history and resets moves. |
| Add spare bolt | Adds one empty bolt; at most two extra bolts. Counts as a move. |
| Next puzzle | Moves to the next level after a win; unavailable in Daily. |
Use help deliberately
Try explaining the next move to yourself before asking for a hint. If the suggested move is useful, follow it and scan again. Extra bolts lower the pressure, so comparisons with a friend are clearer if you say whether you added space. The game does not assign separate scores for assisted and unassisted play.