Variant Sudoku

Between Lines Sudoku Explained in One Short Example

0:18 · Between lines · Variant Sudoku

A four-cell between line has circles of 2 and 7. An 8 on the line fails because it is outside 2 to 7, and 5 and 4 both fit.

Transcript

  1. 0:02Digits on the line sit strictly between the two circled digits.
  2. 0:06The circles hold 2 and 7.
  3. 0:098 is outside 2 to 7.
  4. 0:125 and 4 both sit between 2 and 7.

The rule

A between line joins two circles. Every digit on the line must be strictly greater than the smaller circle and strictly less than the larger one. Either end can hold the bigger digit.

The circles set a range, and the length of the line decides how wide that range has to be. Both the circles and the line cells get narrower as you learn more about either.

Worth memorizing

  1. The circles can’t be consecutive if any cell sits between them.

  2. A long line needs its circles far apart: three cells between need a gap of at least four.

Practice between lines in the lesson

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