(由 Microsoft 翻譯) 您可以採用以下兩種策略:
1) 尋找群組、行或列中數字的唯一可能位置,例如:
在最右邊的群組中,考慮數位 9 的唯一可能位置:

由於數位 9 已出現在前兩行中,因此此組中 9 的唯一可能位置是第三行中的剩餘空白:

2) 尋找空白中可能的唯一數字,例如:
考慮突顯的空白:

數位不能為 2、3、4 或 5,因為這些數位已存在於同一組中,並且不能是 6、7、8 或 9,因為這些數位已經在同一行中。因此,唯一可能的數位是 1:
(原文) Basic Strategies of Sudoku
You can adopt the following two strategies:
1) Find the only possible position of a number in a group, a row or a column, for example:
In the rightmost group, consider the only possible position of the number 9:

Since the number 9 has already appeared in the first two rows, the only possible position of a 9 in this group is the remaining blank in the third row:

2) Find the only possible number that can appear in a blank, for example:
Consider the highlighted blank:

The number cannot be 2, 3, 4 or 5 as these numbers already exist in the same group, and it cannot be 6, 7, 8 or 9 either as these numbers are already in the same row. Therefore, the only possible number is 1: