Contents
Introduction
Some Sudoku puzzles can be solved with logic alone, but some will be scratching your head (or pulling out your hair) to find the solution. A sudoku puzzle with an empty rectangle in the center can be confusing, but once you figure out how to solve it, you’ll find it’s not as challenging as you might think.
This empty rectangle sudoku puzzle falls into the latter category.
Take your time, look at all the possible strategies, and see which one works best in this guide on how to solve an empty rectangle sudoku puzzle.

There are two ways to solve an empty rectangle sudoku puzzle: using the rules of sudoku or using logic and trial and error.
This article will cover both methods so you can figure out which works best for you.
Once you know how to solve one type of sudoku puzzle, you can apply the same rules to solve any other kind of sudoku puzzle, whether it’s in a book or on a computer screen.
So, hopefully, you’ll find it useful to know how to solve this tricky Sudoku puzzle if you should encounter one in the wild.
Here’s how it goes
What is an empty rectangle in Sudoku?
An empty rectangle is an unsolved region in a Sudoku grid that has four squares in it, two on the top and two on the bottom.
The squares must all be different numbers, and no number can appear twice in the same row, column, or empty rectangle.
An empty rectangle is a rectangular block of cells in a Sudoku puzzle that are all empty.
They can be 2×2, 3×3, or 4×4.
They are very important in solving the puzzle, as they can help you determine where the other numbers go.
Video Tutorial
The Empty Rectangle Part 1
The Empty Rectangle part 2
Types of Empty Rectangle Sudoku Puzzle
Empty Sudoku Puzzle has a lot of Categories few of them are In front of You, So keep a focus on Clearing the concept of solving the Puzzle easily.
Type No.1: Empty Rectangle In Boxes
Candidate 8 is spread out across the board in diagram 2, but when you think about the rectangle, you have to think about each box individually.
That’s why the boxes are different colors.
In this case, it only works if there are at least two candidates and four or more empty cells in the box.
The empty rectangles are shown by the Red Cross.
Each one of these imaginary rectangles is different from the other ones.

Type No.2: Empty Rectangle In lines
A vertical and horizontal gap will always be found in which two Empty Rectangle Lines can always be imagined.
This is true for any shape of the Empty Rectangle (ER) (ERLs).
These two lines can be drawn inside the box and not touch the ER.

Type No.3: Empty Rectangle Intersection
Once we know where these lines meet – the Empty Rectangle Intersection – we could quickly forget about them (ERI).
In the diagram below, the ERIs are shown in a dark brown cell.

How do you fill an empty Sudoku?
There are many ways to fill an empty Sudoku.
One way is to find the smallest number that will go in every row, column, and block.
- The most common way to fill in an empty Sudoku is to start with the 1s. This is because, if you can get the 1s in the right places, the rest of the puzzle will usually fall into place.
- However, there are other ways to fill in an empty Sudoku, and it all depends on the numbers that are already in the grid.
- For example, if there are lots of 6s in the grid, it might be a good idea to start with the 6s. That way, you can quickly fill in some of the other squares, and it will be easier to
The Goal of Empty Rectangle Sudoku
The Gole of ERS is to Solve properly.
There is only one rule when solving empty rectangle sudoku: Each row, column, and region must contain all of these numbers: 1, 2, 3, and 4.
Empty rectangle sudoku can seem overwhelming at first because you are being presented with so many numbers in such a small space; however, once you know how to solve them it will be easy.
Once you have mastered empty rectangle sudoku, they will quickly become your favorite type of sudoku puzzle!
To get started on your path to solving it efficiently, try doing some sample ones so that you get used to working with them.
That’s all there is to it! Now that you know how they work.
Techniques for Solving empty Rectangle Sudoku
There are a few different techniques that can be used to solve an empty rectangle Sudoku.
- One technique is to start by filling in the easiest numbers in the easiest squares. This will help to give you a few more clues about the rest of the puzzle. You can then use those clues to help you fill in other squares.
- Another technique is to look for patterns. Often, there will be a pattern in the numbers that appear in more than one square. If you can identify that pattern, you can use it to help you fill in other squares.
- The Next technique is to try and find a number that will work in both the left and right columns.
- The next one is to try and find a number that will work in both the top and bottom rows.
- The Next Technique is to try and find a number that will work in both the left and right columns, as well as the top and bottom rows.
Methods of Solving empty rectangle sudoku
There are a few different ways to solve an empty rectangle sudoku puzzle.
- The most common method is to start by filling in the numbers 1-9 in the empty squares in the grid, and then solving the remaining squares using the standard sudoku rules.
- Another method is to start by filling in the squares in the bottom row, and then working up the grid from there. This can be helpful if you are stuck on a particular square and can’t seem to find a valid solution using the standard rules.
- A third method is to use a technique called “forcing.” This involves guessing a Value and Just put into the Box.
The beauty of this puzzle is that, unlike the standard Sudoku puzzle, there is more than one way to solve it.
There are an infinite number of ways to solve an Empty Rectangle Sudoku puzzle.
In this article, we have shown you a few possible solutions for a 4×4 grid.
How do you solve a unique Empty Sudoku rectangle?
There are a few different methods that can be used to solve a Sudoku rectangle.
- One method is to start by solving the four corner squares. Once those are solved, the rest of the puzzle can be completed by using the digits that are already in those squares.
- Another method is to solve the two diagonals first. This will give you a good idea of which squares should contain which numbers.
- The last step is to fill in the remaining squares using the digits that are already in the grid.
The best way to solve a Sudoku rectangle is to start by filling in the numbers 1-9 in the four smaller boxes.
This will help you to determine where the numbers should go in the larger grid.
You can then use the process of elimination to figure out where the other numbers should go.
How ERS works
With regular sudoku, you have a 9×9 grid of cells containing numbers 1-9.
You also have a set of rules that describe which numbers should appear in each cell and how they should appear.
One such rule might be Each row and column contains one of each number from 1-to- 9.
With empty rectangle sudoku, it’s similar but with a catch: You only have 8 cells!
So instead of 81 possible solutions for regular sudoku (81 because there are 9 columns x 9 rows), there are only 32 possible solutions for empty rectangle sudoku since you only have 8 cells.
Rules for Solving empty rectangle sudoku
There are a few basic rules that will help you solve any empty rectangle sudoku.
- The first is to focus on the rows and columns. If you can get a few of them filled in, it will make the rest of the puzzle much easier to solve.
- The second rule is to look for groups of squares that are already filled in. If you can find a group of squares that are all in the same row, column, or 3×3 square, it will be easier to figure out the rest of the puzzle.
- Next, look for groups of two squares that share a side, and mark the shared number in both squares. These squares will then have to have the same number in them.
- The final rule is to use the process of elimination.
Conclusion
Empty rectangle sudoku is a fun and challenging puzzle that can be solved in a variety of ways.
This article provided a few tips to help get you started.
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This blog post introduced the concept of empty rectangle sudoku.
It explained how to solve the puzzles, and provided a few examples.
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