New: Kerb Clash, clear the jammed car parkNew: Sudoku and Minesweeper, classic puzzles that play offlineInstall any game to your home screen

Binairo Gaps: One Square Between Two Alike

The gaps technique says: when two alike have exactly one square between them, that square is the other colour. If it matched them, it would make three in a row.

Open Binairo full screen for more sizes, saved progress and best times.

This is the second of the Binairo techniques.

The rule

  1. Look along a row or column for two of the same colour with one empty square between them.
  2. That square is the other colour.
Gaps: one square between two yellow A row of six with yellow in squares 2 and 4. The square between them, 3, must be teal. 1 2 3 4 5 6 1
Yellow in squares 2 and 4: square 3 must be teal.

In a real puzzle

On the 10×10 every technique page follows, the first gap comes at step 15. Row 1 starts with teal in columns 1 and 3, with column 2 empty between them. If column 2 were teal, columns 1 to 3 would be three teal in a row, so it’s yellow.

Step 15: gaps Hard level 2 at step 15, with row 1 highlighted and the squares this step settles marked. 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 10
Step 15: one square between two teal in row 1, so it’s yellow.

How often you’ll need it

Every one of the game’s 150 levels uses gaps at least once. On the 10×10 here it’s 7 of the 57 moves; across the Hard levels it averages about 12 per puzzle.

Next steps

Questions

What about a gap of two squares?

Two empty squares between two alike don’t settle anything on their own: one of each colour, either way round, keeps the rules. It’s only a gap of exactly one square that’s certain.