Strategy is the name of the game when doing sudokus.

Strategy can be expressed very simply, or with minute detail. Generally, people use something in between.

The simple strategy is to just put the numbers where they must go.

This is the heart of sudokus. It is easy to say, and in each particular case, it is easy to do.

So what’s so difficult?

One thing that is difficult is finding those few squares that must contain a particular number.

One way of rating a sudoku is by the number of squares that can be filled based on only the numbers given at the start. This just emphasizes that difficulty really lies only in finding those squares that can be filled based on available information.

Looking for the squares that can be filled is often a sequence of failed efforts.

Failed efforts are the key to understanding the appeal of sudokus. The lesson of life that we learn from practicing these puzzles is that success always follows many failed attempts. It is indeed because of failed attempts that we gain knowledge in life. The more we know what doesn’t work, the more we know that what is remaining must work.

This leads to another fundamental idea that is repeated continually in sudokus: Look for the place where the number must go. Using this principle, when we put a single number, we feel a measure of satisfaction that comes with that little bit of success.

After all, the first few numbers are typically hard to find because there simply isn’t as much information to use to solve the puzzle.

There is another point midway through the puzzle when there is more information, but not the right kind. Then the abundance of information serves to make it more difficult to see the one or few squares that are possible to fill in. This is the portion of the game that gives the most enjoyment.

As we continue to search for the pattern that leads to the answer to the next square, we become more and more aware of beauty of the many patterns that make up the puzzle.

And human beings love patterns.