Surface Triple
Extreme
Used by Smart Hint
Two overlapping groups of runs differ by three cells — subtracting their clue totals ties those three digits together, ruling out any that can't be completed.
- Cells that establish the pattern
- Where the conclusion lands
- Digit ruled out
How it works
- The down clues cover the tinted block for 16 + 11 = 27; the across clues cover it plus the row's last three cells for 13 + 33 = 46.
- So those three cells total 46 − 27 = 19.
- Three different digits reaching 19: the two biggest available are 9 and 8, so the smallest of the three can be no less than 19 − 17 = 2.
- A 1 anywhere among them is impossible. Strike it from all three.