Sudoku-Centered

Size:

9x9.

Elements:

1, 2, 3, 4, 5, 6, 7, 8, and 9.

Groups: Twenty-eight total.

The 9 rows.

The 9 columns.

The 9 3x3 squares.

The centers of each 3x3 square.

Instructions:

Precise details on group numbering.

Answer grids:

Puzzle Difficulty levels and Examples

Difficulty Level	Low	High	Example
Easiest	2	2	Puzzle   ·   3-steps   ·   All-steps   ·   Solution grid
Easy	3	4	Puzzle   ·   3-steps   ·   All-steps   ·   Solution grid
Medium	5	8	Puzzle   ·   3-steps   ·   All-steps   ·   Solution grid
Difficult	9	14	Puzzle   ·   3-steps   ·   All-steps   ·   Solution grid
Challenging	15	20
Tournament	21	29