By Grace Gilson

Most days, I play the New York Times Sudoku: Hard level. Every day, there is a new puzzle to solve! The more I have played, the faster and faster I get. I also have learned a lot of strategies to solve a puzzle. So, if you are looking to try, or master, something new, here is my advice.

What is the goal of Sudoku?

Fill in each of the 9 3×3 squares, rows, and columns with the numbers 1-9. 

Before I get into tips to solve the puzzle, I recommend beginning with the Easy level, progressing to the Medium level, and finally the Hard level.

1. When you first start your puzzle, fill in all possible “candidates” for each square. If there is already a 1 in the 3×3 square where the blank square is located, don’t write down a 1. If there are no 1s in the square, the row, and the column in which the blank square is located, pencil/type in a 1. For each square, type in all of the possibilities.

2. Repeat until all of the blank spaces are penciled in!

Here is an example from the December 5th easy puzzle

3. Once the whole puzzle is filled in, fill in the ones with just one number. Adjust candidates accordingly.

4. Then it gets a bit more difficult…

In this box, notice how there are 2 boxes with candidates 3 and 6. This means that if one is 3 the other is 6 and vice versa. It also means that 3 and 6 will not appear anywhere else in the square. This means that the center top square is 9 and then the middle square is 2.

It works in rows too. Since 3 and 6 must go in the 1st and 3rd squares, the 2nd must be 2.

As you progress to harder levels, you will have to recognize this pattern with groups of three or more

5. Next, you need to see what boxes provide the only number for that row. In the column below, the only opportunity to get a five is the highlighted box, so that has to be 5.

6. With these strategies, I think you should be able to start solving sudokus! Always remember to write in the candidates!