Windmill Sudoku - Rules & Guide

Tip 1: Use long overlapping areas

Different from the overlapping of a single 3x3 grid in Samurai Sudoku, the overlapping area of Windmill Sudoku is a long strip of "2 grids connected together" (including 18 grids). This means that within the overlapping area, numbers are not only bounded by the squares, but are also strongly repelled by rows or columns that span 2 squares. Prioritizing observation and utilizing these long overlapping areas can often squeeze out many key candidates.

Tip 2: Surrounding repulsion of the central disk

Out of the nine 3x3 palace grids on the central disk, 8 are "shared" by the peripheral disks, but the centermost palace grid is purely its own. When you solve the numbers in the four outer "windmill blades", the numbers act like propellers, exerting repulsive forces on the central disk from all sides. Using this all-round crossfire, you can quickly lock the numbers on the center disk.

Technique 3: Dislocation scanning method

Because the peripheral disks are arranged "misaligned" (for example, the upper disk is to the left, and the right disk is to the upper side). When performing long-distance scanning in rows and columns, be sure to see clearly whether the line of sight has penetrated into another overlapping disk. Don't confuse the independent disk queues with the shared queues. If you reason along the direction of rotation of the "windmill", your ideas will be smoother.

Example picture: The yellow line frame is the center disk, observe its unique misalignment and overlap

A: The biggest difference is the overlapping area and location. The Samurai Sudoku has 1 3x3 square on each corner; the Windmill Sudoku is a "dislocation" overlap, with two 3x3 squares on each outer disk and the central disk (a total of 18 squares), thus forming a rotationally symmetrical pinwheel shape.

A: No special rules. It is just an ordinary 3x3 grid at the core of the central 9x9 board. But precisely because the eight peripheral palace grids are shared by the outer disk, this central independent palace grid often becomes the "terminal station" for collecting clues that are excluded from all directions, and is a key area for connecting the previous and the next when solving problems.