Strategies for always beating sudoku are many and varied, but the best one is the one that makes the most sense for you and your specific game style. Some are simpler, while others require more time and practice. Using several techniques is also an excellent option for beginners. Here are some techniques for solving sudoku that is used by aficionados.

Nishio strategy

The Nishio strategy is a simple way to always beat Sudoku puzzles. It works by removing the candidate that is not the right choice and replacing him with a different one. This strategy is similar to the proof-by-contradiction method used in mathematics. The player makes an assumption that a cell is a digit “k,” then finds a contradiction and removes that cell from the candidate pool.

This strategy requires no extra work, and it is the easiest way to win Sudoku. Nishio(S) is the set of cells that participate in at least one valid placement. This strategy can also be applied to other problems.

Unique rectangle method

The Unique rectangle method is a simple way of always beating sudoku. It works by identifying four cells with two candidates in each row or column. You must place your Unique Rectangle in one of these cells. If you cannot place a Unique Rectangle in any cell, you can use the Avoidable Rectangle technique. This method is similar to the Unique Rectangle method but has some differences.

This method involves making an assumption about the puzzle composition. In this case, you should look for an extra digit in one or more cells. Then, switch the numbers around to form a working solution.

Unique square method

You’ve probably noticed patterns in how you’ve solved Sudoku puzzles. You may have started by filling a square with a single value, then eliminated all the others before reaching a solution that worked. Or you may have had to memorize many different values for multiple squares.

Obviously, this isn’t a good strategy because Sudoku puzzles that have more than one solution are not valid. They would lead to a logical contradiction. Also, solving the puzzle with more than one solution is illogical. A more logical approach is to start with an empty board.

In order to solve the puzzle, you have to assign integers to each vertex. If the vertices of two adjacent squares don’t have the same integer, it’s not a solution. This constraint means that no two vertices must be the same. This constraint is also known as the NP problem. It’s very hard to solve a Sudoku puzzle without a solution.

X-Wing strategy

If you’re constantly losing at Sudoku, there’s a strategy you can use to always win. The X-Wing technique allows you to find patterns in rows and columns that contain only two matching cells. It’s an important skill to learn, and it’s one that will help you master the game for good.

The X-Wing pattern appears in orange or yellow cells. This pattern makes it easier to spot than hidden subsets. You can get two solutions from each column, but it’s rare to see more than two victims at a time. This is because of how the X-Wing pattern affects the way each cell is arranged in the grid.

The XY-Wing pattern works by using a similar reasoning system. A 3 must occur in one of three identified rows. In addition, the three columns must contain a 3 for the pattern to occur. By circling a red candidate, you can eliminate the candidate in the other two columns.

Swordfish strategy

The Swordfish Sudoku strategy involves locating an extra cell in a row or column that has a shared cell with another cell. The extra cell must also be out of the regular fish pattern. This strategy can be applied to any shared row or column. The Swordfish strategy works well in solving a puzzle with four or more rows or columns.

To find the Swordfish, focus on a single number (one through nine). Look at the pencil marks in each row and column and note any row that has at least two or three squares containing the current number. Alternatively, try to find three rows and three columns with this same number.