We ended up filling in 4 of the 9 squares. In fact, this is already a major victory, since the inscribed values will allow us to quickly "click the puzzle".
We suggest using the "hanging fruit" technique. That is, again we need to look for those areas where there is literally one value left to write. Unfortunately, freebies are not visible on the playing field.
But the eye clings to the third column, which contains 9, 8, 1, 2, 5, 7 and 3. This means that we need to try to fit the numbers 4 and 6. We look to see where they fit more. In the neighboring squares are 4 and 6 (bottom right). We distribute our numbers accordingly. The four should be inserted into the bottom right corner of the left square. The six is inserted in the upper right corner of the bottom left square.
We get away from analyzing columns and rows. We have the data to place a one. The number 1 should fit in the middle of the bottom left square. Why is this happening? Look that 1 already stands in the left column (center square) and is repeated in the top row (center square at the bottom). Consequently, we simply have no other place to put a 1.
Let's look at what we get in the bottom left square. We see there 2, 6, 1, 3, 7 and 4. Three values are missing: they are 5, 8 and 9. Naturally, we move by the method of elimination.
We already have a five in the left column + inscribed in the bottom two lines (1-3-4-5-8-7 and 7-4-5-5-3-1-2). Thus, we just absolutely have to insert the five into the top row of the bottom left square. That is, the number 5 should appear in the center column of the square.
Now the lower left square contains the digits 2, 5, 6, 1, 3, 7 and 4. It remains to attach 8 and 9. We recommend using the proven elimination technique. There is already an eight in the center line at the bottom (note the center of the bottom right square). The whole line looks like 1-3-4-5-8-8-7. So we must not repeat. We write 9 in the left center line of the bottom left square. Accordingly, 8 should be placed below it. The bottom line will look like 8-7-4-probel-5-3-1-2-6.
A radical breakthrough
Each new number on the grid brings us closer to victory. After experimenting with the bottom left square, we can see what progress has been made. A total of 5 squares out of 9 are filled in. With so many values entered, solving Sudoku is one fun (or is it?).
Let's see what happens in the bottom center square after the "neighbors" are filled in. It contains the numbers 1, 4, 5, and 3. That is, we need to figure out where to put 2, 6, 7, 8, and 9. It's a little tricky, but let's figure it out.
On the right side of the column is the number 8. Based on this, we put 7 in the upper right corner of the lower center square. Accordingly, 8 should appear next to it. The number will appear at the top center in the lower left square.
Moving on. We have the center bottom square now contains the values 1, 8, 7, 4, 9, 5, and 3. We need to figure out how to fill the empty cells with the numbers 2, 6, and 9. It's easy enough to see what happens in the squares next door. The 9 is already inscribed in the left column (the center of the left square). Accordingly, that there is room for the nine only in the lower left corner of our square.
So, the bottom center square has been transformed after filling. Now it has 1-8-7-propel-4-propel-9-5-3. We need to understand how to put 2 and 6. From the analysis of the "neighbors" it is not clear how to place the numbers. I think we've hit a dead end.
To get out of it, let's look at the grid as a whole. We are interested in the values that are in the upper left square. He needs 2, 3, and 4.
Let's deal with triples. The number 3 is in the top row (left square), and also appears centered in the top square). Accordingly, we realize that a 3 can only be placed in the top row of the upper left square.
Let's go further and analyze where to put the 2 and 4. At the top of the central square there is already a 4. This makes it clear that the 4 can be placed only in the bottom row of the upper left square. Accordingly, the 2 will fit in the center cell. Congratulations! We have filled in another sudoku square. Now the numbers in it look like 5, 3, 9, 7, 2, 8, 6, 4 and 1.
It is interesting that we have filled in the center part of the puzzle. In total, the sudoku solved 6 squares 6 squares out of 9 squares. How to solve the puzzle further and what should be considered?