There are seven methods for Jiugongge skill formula, namely: formula method; Trade union department; Patrol grid method; Exclusion method; Undetermined method; Formula method; Row and column method.

Formula: It is very important to master some formulas when playing Jiugongge, such as' 2,4 is the shoulder, 6,8 is the foot, up 9,down 1, left 7 and right 3', which means' 294,753,618'.

Union division: Find some identical numbers in two lines of three parallel nine squares, and then use nine squares to find the positions of the numbers in the other line. This method is very suitable for advanced Sudoku. But it will be more difficult to master in the early stage.

Patrol method: find out some numbers that appear frequently in each nine-square grid, and then get their positions in other nine-square grids. This method is generally applied after union division.

Rank method: this method is generally used in the final stage, using the breakthrough from the ranks to complete the nine squares.

Exclusion method: this method is a bit difficult to operate, that is, observe each line or nine squares. If there is no other number to fill in a position, then fill in the remaining numbers and try to see if you can draw a conclusion.

Undetermined method: this method is very suitable, that is, temporarily determine a number in a certain area, and then use it to exclude it. Generally speaking, this method can be used with other methods.

Formula method: this method is to bring in mathematical formulas. With the middle number as the center, it is' n-1,n, n = 1' obliquely, so the sum of each row is 3n.