Hints, Coach and "Why not?"
The coach walkthrough
The coach turns the next human step into a four-stage lesson. Each stage highlights only what it needs, so you can stop at "Where to look" and try yourself, then read on when you want the rest.
- Where to look: a tinted run or cell.
- The pattern: the candidate digits that matter.
- The logic: the deduction in plain words, with the arithmetic.
- Conclusion: the placement or the removal, ready to apply.
The hint level in the settings caps how hard a technique the coach may use. "Singles only" keeps it to the basics; Extreme allows every technique the solver knows.
The Hints panel
Hints lists every technique that is available on the board right now, with a count of how many steps each one gives. Pick one to open its walkthrough. This is the fastest way to see what you have missed.
The "Why not?" prover
Select a cell, tap Why not?, and choose a candidate. The app:
- Places the candidate on a copy of the board.
- Follows every forced move: last cell in a run, one candidate left, an impossible sum.
- Finds the conflict, if there is one.
The proof has four stages: the assumption, the digits it forces, the conflict and the conclusion. If the assumption does not conflict, the app checks the exact solver: a candidate that leaves the puzzle with no solution is impossible even when the short chain misses it.
The solve path
Path lists the techniques the puzzle needs, hardest first, with how often each one appears. It is the plan the solver follows, and a good guide to what to learn next.
Next: The Daily Puzzle.