Sudoku Strategies for Beginners: Where to Start

My main criteria for starting is to look at high population areas, a row, column or block. Having more numbers in a group gives you less possible choices, a rule that was finally explained to me. After wandering randomly over the Sudoku board in an attempt to place numbers in blank spaces, I now rely heavily on this rule.

Naked singles: if a cell can only have one number, that's the number you use. Here are the basic steps to apply this technique to solve Sudoku puzzles: Step 1: Check the row, column, and box to which the selected cell belongs. Step 2: See what's already taken. Step 3: Look for numbers that only appear once in any of these areas and eliminate them from other cells in the same area. Step 4: Continue filling in numbers and apply this technique as needed.

Hidden singles work in reverse. Instead of looking for possibilities for a particular cell, you look at an entire row, column or grid and ask for each number: where could this number go? In many cases there will be only one possible place for it and then that cell must be the solution, no matter where else the number might fit. Be warned, it takes a lot of looking at a Sudoku to train your eyes to find all the hidden singles!

For now, just do Easy puzzles and try to learn these two techniques. I tried to learn all the techniques at the same time and it was a complete jumble of confusion. Once you learn the basics of naked and hidden singles you can start to do Medium puzzles.

“Write in the small numbers. The candidates. I was a bit frustrated at first because it seemed like I was cheating or something. It wasn't cheating; it was keeping me from having to make a lot of guesses which meant I had to do a lot of erasing. There was a lot of eraser dust. Use pencil marks.”