PUZZLE TECHNIQUES

HITORI SOLVING TECHNIQUES

Learn advanced strategies and methods to solve difficult hitori puzzles. When you have learned our solving techniques, then you can try to play hitori online.

• Whee a number has to be deleted, we will make the cell black.
• When a number must stay on the grid, we will mark it with a circle.

Only make choices based on logical deductions.

TRIPLETS

Scan rows and columns and look for triplets

The first cell (=C2) and the last cell (=E2) of a triple become black. The middle of the triplet (=D2) gets a circle and must stay.

A CELL BETWEEN A PAIR

Look for a cell between a pair in rows and columns.

In this hitori we have pair 2 in cells C1 and C3 a number 1 in cell C2. Number 1 in cell C2 gets a circle and must stay.

CIRCLE DETERMINATION

Look for cells with a circle in rows and columns and with the same number in the same row or column.

We have a circle in C2 with number 1 and in the same row with have number 1 in cell E2. Number 1 in cell E2 now becomes black.

PAIR AND SINGLE

Look for an adjacent pair and a single with the same number in a row or columns.

We have number 5 in cell E1, E2 and E4. E1 and E2 or an adjacent pair, so E4 needs to be black, because when we put a circle in E4, we have a conflict with one of the rules of hitori. You may not have 2 adjacent black cells.

CIRCLES AROUND BLACK CELLS

Look for black cells in the grid of the hitori puzzle.

Using the triplet technique we could place a circle in cell D2 and turn C2 and E2 into black cells. Now we may place circles in the cells that have a horizontal or vertical connection with a black cell. So cells, C1, E1, B2, C3 and E3 receive a circle.

NO ISOLATION

Make sure that a black cell never isolates non-black cells.

Cell E4 needs a circle to avoid isolation of non-black cells.

TIP: the corners of a grid or a good place to look if you want to avoid isolation!

BORDER PAIRS

If you have two or more doubles at the border, you can place some circles.

Cell A1, B1, A4 and B4 must have a circle to avoid isolation.

TWO PAIRS WITH COMMON NUMBER BETWEEN

If you have two pairs with a common number between them, than this cell must become black.

Cell C3 must be black. If C3 is a circle, than C1 and C5 must be black causing problems with D1 and D5.

PAIR AND CROSSED PAIR

When you have a pair and a crossed pair, than one of the cells of the crossed pairs is always black. So you can place two circles next to the crossed pair.

Cell C3 or D4 will be black. In both cases you may place a circle in C4 and D3.