Dutch Whispers Sudoku
A whisper board: along the green line the digits read 2·9·1·8·2·9·1·7·1 - every neighbouring pair differs by at least 5.
Dutch Whispers Sudoku is Classic with a green line drawn across the grid. Wherever two cells touch along that line, their digits must differ by at least 4. Everything else is unchanged.
The rule
- All the Classic rules apply - 1-9 exactly once in every row, column and 3×3 box.
- Any two adjacent cells on the line must differ by 4 or more.
- The rule applies only to neighbours along the line, not to the line as a whole. Digits can repeat on the line if they are far enough apart on it - the row, column and box rules still forbid the rest.
Unlike its stricter cousin, a Dutch line can contain a 5, because 1 and 9 are both exactly 4 away from it. The gentler gap means more digit pairs qualify, so the line constrains the grid less tightly - a good place to meet whisper lines for the first time.
How to play, step by step
- Start at the ends of the line. They have one neighbour instead of two, so they are the least constrained by the line itself - but the cells next to them are the most constrained, and that is where the chain usually breaks open.
- Work the alternation. Once one cell on the line is fixed, its neighbours are forced into the opposite band. Follow that along the line before touching anything else.
- Cross-check with the box. A line usually crosses several 3×3 boxes. A digit forced by the line is also a digit removed from its box, which often unlocks cells nowhere near the line.
- Then solve normally. Away from the line it is plain Classic Sudoku.
Common mistakes
- Applying the rule to non-neighbours. Only cells that actually touch along the line are constrained. Two line cells three steps apart have no direct relationship.
- Forgetting the line bends. The line follows cells, not straight rows - it can turn diagonally, and the neighbour relationship follows the line, not the grid direction.
- Assuming it works like German Whispers. Here the gap is 4, so a 5 is allowed - and pairs like 1-5 or 5-9 are legal.
Difficulties & scoring
This type can be played on all five difficulties. The score multiplier for Dutch Whispers Sudoku is ×1.2 - so every point counts for more on this variant. The "normal time" below is tuned for this type.
| Difficulty | Base score | Max (×1.2) | Normal time | Hints |
|---|---|---|---|---|
| easy | 150 | 360 | 6 min | 5 |
| medium | 300 | 720 | 11 min | 4 |
| hard | 600 | 1440 | 17 min | 3 |
| expert | 1000 | 2400 | 22 min | 2 |
| evil | 1500 | 3600 | 34 min | 1 |
How the score is calculated
Your score builds up from 0 as you place correct numbers, up to the full base when the board is finished. Then two bonuses are added:
base × your progress × (1 + combo bonus + time bonus) × 1.2
- Progress: the live score climbs from 0 to the base as the grid fills with correct numbers.
- Combo bonus (up to +50%): keep a clean run for the full bonus. Each error or hint is a combo break that shrinks the bonus - but it never takes Sparks away below the base.
- Time bonus (up to +50%): beat the normal time and you earn extra, proportional to how much faster you were. Finishing slower than normal costs nothing - there is no time penalty.
- The total is multiplied by ×1.2 and never drops below 0.
Coins
The coins you earn reflect your score - the more Sparks, the more coins (about 1 coin for every 45 Sparks, minimum 1). Spend coins in the Shop on hints and Jokers.
Tip: a clean, hint-free solve under the normal time scores the highest. The Daily Challenge is always Classic and fully scored.
Where to play it
Dutch Whispers Sudoku scores at 1.20× here, because the extra rule is real work on top of classic logic: The gentler whisper: digits touching along the line must differ by at least 4.
Difficulty and type are two separate dials here: the type sets the extra rule, the level sets how much of the grid you start with. Hard Sudoku leaves 26 of the 81 cells filled, where scanning gets you started and then leaves you stranded; Expert Sudoku leaves 25, where the beginner tools dry up almost entirely. Take Dutch Whispers at the gentler end while the pattern is still new, and move up once it stops being a fight.