Sudoku Single Digit Patterns (Skyscraper Suddoku, 2 String Kite, Turbot Fish, Empty Rectangle)

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This brief article is all about Sudoku Single Digit Patterns which are Skyscraper Sudoku, 2 String Kite, Turbot Fish Sudoku, and Empty Rectangle, all these patterns are Sudoku Variant and not that difficult for those who’ll stick with us till the end because I am going to share some tips and tricks that will stand you out among other guys if you’ll successfully implement them


Skyscraper Sudoku (Single Digit Pattern)

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Now let’s check why this sudoku variant is named as a skyscraper.

“Due to the two unequal heightened building’s resemblance, it is termed as a skyscraper which is an easy to judge sudoku variant, and there’s nothing complicated in this type of sudoku variant”

You’ll have to focus on some basic core concepts of this sudoku variant, and you can easily spot this pattern.

Stick with us till the end; we’ll make you professional in Sudoku single-digit pattern; it’s a unique form of Turbot fish which we’ll discuss in the next few paragraphs.

Skyscraper Sudoku is rather seen as two Sashimi X wings.


It is not that complicated if you’ll take care of the following points

  • Always try to concentrate your full attention on a single digit instead of focusing on more than two digits at a while
  • Next, you’ll have to find those 2 row’s or column’s where two candidates with the same exact digits are present
  • If you successfully find those two candidates in the same row’s or column’s, you’ll be considered a true guy
  • And out of those candidates who can see both of the cells can therefore be eliminated

Let me explain it to you more precisely, if two cells of a particular candidate are in the same exact column but in different rows, one cell in the first row while the second one is in the second row but both of these row’s belongs to the same column then the candidate who’ll see the other two cells will not be the solution, hope so this will clear most of your doubts.

Single Digit Pattern (Sudoku skyscraper example)


Let’s dive into the example

In this particular example, G6 eliminates in every case, but in the last case, you’ll see how it directly eliminates

Case No 1 & 2

Now you’ll see G6 elimination among each other’s:-

Candidate 4 must be the key in H4; if it is the key in b3, same in the next case if it is the key in H3, then it must be the key in B6


Now let’s see how G6 eliminates directly:-

If it is the key in both B6 or H4, then it may result in the direct elimination of G6.

How to solve skyscraper Sudoku

Now let’s come into the matter of Skyscraper Sudoku Solution

If you’ll follow some of the given point’s you’ll undoubtedly solve the skyscraper sudoku variant

Let’s create conditions

In case If you want to see all skyscrapers at once from 1 to 9, then what would be the solution? You’ll just have to spot clue no 9

But in case if you want to see the highest skyscraper 9, you’ll just have to spot clue no 1

In any sudoku variant, normal Sudoku rules play a vital role in winning

You’ll have to prioritize the highest sudoku digit’s; I’ll tell you the main reason for prioritizing the highest one in the rules section


Following are the rules you’ll have to imbibe in your mind when playing skyscraper sudoku.

Now you got the idea of solving skyscraper sudoku; let’s take a look at the assigned rules in order to be a champ.

Remember the normal sudoku rules.

As you may be aware of both of these terms; highest skyscraper, which is 9, the lowest skyscraper, which is 1, every row, column and three by three box contain 1 to 9 skyscraper terms once in a while

This point is worth considering that in each column and row.

No of visible skyscraper’s= Clue Value

But the only prerequisite is to view it from the clue direction.

As you know, in digital terms as we go ahead with the digit’s its dominancy is increasing, same is the case with this Sudoku Variant where highest sudoku skyscraper dominates on the lower one and hide its presence, but there are some prerequisites in this already assigned rule that if the distance between two digits is quite enough, then the rule will not implement and does not block the view of the lower one, let me clear it to you through an example like if skyscraper 1 is at one side while the highest skyscraper on the other side of the grid then due to a lot of distance gap this rule will not implement

Tips and techniques

Following are the tips and techniques that will dominate you among other candidates if you’ll implement all or some of them carefully or intellectually

Along rows or columns, any nine clue leads to the visibility of every skyscraper once in a while

While on the other hand, anyone clue leads to the visibility of 1 skyscraper along with the columns or row’s that also contains digit no 9

If in case, it does not contain skyscraper digit nine but contains any digit other than nine, then skyscrapers 1, 9 and all taller skyscrapers visible in a while

Give some time to brainstorm on this point that how the interaction between different clues are made

You know that each cell along different row’s or columns contain different skyscraper terms, and a skyscraper also represents a building, so we can conclude that every skyscraper along rows and columns are of different height

Sudoku 2-String Kite(Single Digit Pattern)

We called the skyscraper variant the unique form of Turbot fish in one of the above paragraphs, but when it comes to the matter of 2 string kite variant, it is considered as the second special or unique form of Turbot fish often found in sudokus. In this particular variant type, we’ll have to find two candidates lying in the same blocks but in a different row or column-like. In this case, we’ll have to find one candidate from the row while the other one from the column.

Single Digit Pattern(2 string kite sudoku example no 1)Single Digit Pattern(2 string kite sudoku example no 2)

In the left example, out of two strings of candidate no 5, the first one is in the seven no column while the other is in the eight no row. Column no 7 contains candidates r29c7 while row 8 contains candidates r8c49. The last points, which are r9c7 and r8c9, lie in the same box number 9.

Now the conditions are if r2c7 isn’t considered as a true candidate, then r9c7 has to be true, while on the other side, if r8c7 is considered as a false candidate, then e8c4 must be the true one. The same is the case with r8c4, which is not a true candidate, but r2c7 proves it as true.

In the right example, two strings of the same candidate, which is nine linked in box number no 9, where r7c6 can’t be the candidate 9

In this case, elimination will occur something like that those who see the other two cells can be eliminated.

Now let’s see how this technique came into being, turbot fish isn’t considered single pattern sudoku, and it is too much complicated for even a good sudoku player; that’s why 2 String kite, which is considered as a special form of Turbot fish is introduced as a separate single pattern sudoku technique.

How it works

Let’s check the working methodology of 2 string kite sudoku variant.

how 2 string kite pattern works

For a single digit, this particular Sudoku pattern unified and created two sets of pairs, out of which one will place in the row while the other one is in the column section and these pairs are named as strings which represents the structure of the Kite after linkage in a single box.

In this particular pattern, the eliminated candidate would be the one who can see both ends of the strings.

Not 2-String Kite Sudoku

The box wouldn’t be the same for both unified pairs(Unified pairs contain cells in them), and each line contain distinctive cells in the box; the following is the example where we’ll show

Not two string kite pattern example

if we’ll place a single pair containing two cell’s in the same box, it solely degenerates the overall pattern, either this particular case also leads to the elimination of the candidate, but it is still not considered as a two-string kite due to the reason’s I explained

If each line contain indistinctive cell’s, then the result would be like that, as shown below

Not two string kite indistinctive example

Grouped 2-String Kite Sudoku

This particular pattern name represents the functionality of the overall pattern, as the name grouped represents itself that there would be a group of candidates in the strings that take an active part in the competition.

Now let’s dive deep into the concept of eliminating a particular candidate through this pattern.

Overall you’ll have to find a column or row with no candidate at all in their familiar cell, once you have done this, then you’ll have to find a single candidate outside the shared box, now its time to eliminate the candidate from the cell, the candidate would be eliminated that can see both candidates at once right outside the shared box, and this completion leads to the overall formation of a rectangular pattern.

grouped 2 string kite pattern example

There would be something called 19/20 based difference in both original as well as the grouped version of the chain.

Dual 2-String Kite Sudoku

Two string kite formed productively as a result of two same candidates connection with two to four different strings at once while remaining in the common box, and this will lead to the elimination of two candidates and can be considered as one move only and hence, therefore, be called as dual two string kite.

Turbot Fish (Single Digit Pattern)

What Actually Turbot fish is?

Most of the newbies get confused with the name turbot fish. Is it a fish?

Turbot fish is not a fish but an X chain pattern that is used to create a lot of shapes.

Now let me clear this question too, how did the name turbot fish originate?

While playing the game, you can see fish-type shapes when drawing lines in between different color-based candidates; there is also a digital representation of a single-digit one that resembles the fish and becomes the source to give this pattern a unique name.

Single Digit Pattern(turbot fish sudoku example no 1)Single Digit Pattern(turbot fish sudoku example no 2)

It split into different patterns like a skyscraper, two string kites, and an empty rectangle.

A turbot fish is a longer loop possibility based X chain and single-digit solving technique whose minimum length is five, and it is also named a fishy cycle due to its resemblance with the fish, it helps in between four candidates, and this pattern also used a lot of loops with specific loops length in odd terms.

Single Digit Pattern(turbot fish sudoku example no 3)turbot fish sudoku example no 4

Empty rectangle (Single Digit Pattern)

Single Digit Pattern(empty rectangle sudoku example 1)

This pattern is quite different from all previous patterns. In this pattern, a rectangle shape is formed right inside the grid due to 4 cells accumulation in an alternative manner.

There’s an interaction that holds between every cell along the rows or columns inside the grid. In the case of an empty rectangular pattern, the relationship between two cells is named a strong link-based relationship; let’s suppose if these two cells are left in the whole main grid containing a particular candidate, which cell would be the solution for the candidate if cell 1 isn’t the solution then cell no two would be the solution.

An empty rectangle is also considered a rectangle in case if it holds inside the square and its corners lack a particular candidate.

Worth considering, stuff in this particular pattern are strong links, squares, empty rectangles, and a particular candidate.

Now let’s check in this particular pattern that what would be the case or what wouldn’t; if any of the rows of the square contains any corner of the empty rectangle, it would be the solution, but if it doesn’t contain any empty rectangle corner then it wouldn’t be the case we’ll have to search strong links in case if we want the candidate to be the solution.

Now let’s come to the elimination part.

Candidate elimination from other cells of the same column occurs as a result of the solution of one of the cells in the square column that doesn’t contain any empty rectangle corner. Now let’s talk about the elimination directly from one of the strong links which occur as a result of solution for one of the cells in a straight row that doesn’t contain any empty rectangle corner; the candidate would be the solution for strong links other cells which leads to the elimination of the candidate from all cells in the same row.

Related articles

Sudoku Beginners Tips and Tricks

Sudoku Advanced Tricks 

Chess Sudoku

Diagonal Sudoku

Take a look at the article by Wikipedia regarding Sudoku where everything is mentioned including sudoku mathematics, its types, its predecessors, follow the given link

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