What is a W Wing?

W-Wings are easy to spot and often very efficient. They consist of two bivalue cells with the same candidates, that are connected by a strong link on one of the candidates. The other candidate can be eliminated from all cells seeing both bivalue cells.

What is an XY-wing?

An XY-Wing is a group of three cells, one sharing a unit with the other two, each having only 2 candidates. The two cells that share a unit with the first are called the Wings. Each of the wings must share one candidate with the first cell, (that's part of sharing a unit) but of different values.

How does XYZ Wing work?

More precisely an XYZ-Wing has three cells that contain only 3 different numbers between them, but which fall outside the confines of one row/column/box, with one of the cells (the 'apex' or 'hinge') being able to see the other two; those other two having only one number in common; and the apex having all three numbers ...

What is an XY chain in Sudoku?

A XY-Chain is a chain of cells which each contain only 2 candidates. Because the chain is entirely made up by bivalue cells, the link between the 2 candidates in each cell cause strong inference, which allows us to use weak inference between the cells. The shortest XY-Chain is an XY-Wing with only 3 cells.

What does R and C mean in Sudoku?

A single cell is called out by specifying its row and column numbers with an 'r' preceding the row number and a 'c' preceding the column number. Examples: r1c9 means the cell in row one and column nine (the rightmost cell on the top row). r8c3 is the cell on row eight, third cell from the left.

Advanced Sudoku: Y-Wings And W-Wings

What are xwing variations in Sudoku?

An X-Wing pattern occurs when two rows (or two columns) each contain only two cells that hold a matching candidate. This candidate must reside in both rows and share the same two columns or vice versa. In the example shown, an X Wing pattern occurs in row 2 and row 5. Each row has the number 4 in only two cells.

What is WXYZ wing Sudoku?

A WXYZ-Wing is a Bent group of four cells with four candidates (naked), that have exactly one non-restricted common candidate, where the elimination cell(s) can see all occurrences of the non-restricted candidate in the group.

What is swordfish Sudoku?

A Swordfish is a 3 by 3 nine-cell pattern where a candidate is found on three different rows (or three columns) and they line up in the opposite direction. Eventually we will fix three candidates somewhere in those cells which excludes all other candidates in those units.

What is a fin in Sudoku?

These +8 cells are the 'fin'. The 'fin' or 'fillet' rule goes as follows: If you can form an X-Wing by ignoring the fin cells, then you can keep your elimination of any cell that shares the same unit as all the cells in the fin. It's important to remember we can only have one fin at a time!

What is jellyfish Sudoku?

A Jellyfish occurs when in four rows all possible cells for a given digit lie in four columns. This digit can be eliminated from the remaining cells of these columns.

What is a pivot in Sudoku?

The cell in the center is called the pivot. The other 2 cells are the pincers. The chain uses only 3 digits, symbolically named X, Y and Z. Any 3 digits can replace these letters. The pivot contains candidates XY, which explains the name of this technique.

What are the 5 types of wing?

There are also five different shapes used for aircraft wings including rectangular, tapered straight, elliptical, swept, and delta.

What are the 4 different wing types?

There are four general wing shapes that are common in birds: Passive soaring, active soaring, elliptical wings, and high-speed wings.

What is a Lambda wing?

Introduction. The lambda-shaped wing is in fact a delta wing with a crank in the trailing edge region. The existence of the crank at the trailing edge enables the wing to have a higher aspect and taper ratio than a simple delta wing.

Is Sudoku good for your brain?

Sudoku keeps your brain active and reduces the risk of Alzheimer's, a most common cause of dementia that affects a person's thinking and behavioural skills. Stimulates your mind: The game works on your logical thinking process as you are absorbed in solving a puzzle and eventually improve your number skills.

What are the 3 rules of Sudoku?

Is Sudoku a math?

Myth: You must be good at math to play Sudoku

But this is not true. Sudoku is not about adding or subtracting or doing arithmetic – it's about placing numbers 1-9 on a grid, without repeating any of the same numbers within the same row, column or square. Sudoku is not a “math” game, it's a logic game.

What is the 159 rule in Sudoku?

Normal sudoku rules apply: Each row, column, and region indicated by thick borders in the grid must contain the digits 1 to 9 once each. 159: Digits in column 1 indicate the column in which the digit 1 appears in that row (e.g. if r4c1 is a 6, r4c6 is a 1).

What is butterfly Sudoku?

Sudoku is a fun logic puzzle that gives kids a chance to use their logical reasoning and critical thinking skills. In this Butterfly Sudoku worksheet, kids solve four Sudoku puzzles. In each row, column, and block the numbers 1, 2, 3, and 4 must appear once and only once. See in a set (9)

What is diabolical Sudoku?

Classic sudoku: fit the numbers in the grid so that each row, column and square contains the numbers one to nine once only. If you think it sounds simple then try our diabolical sudoku to see how hard it can be. All Sudoku Diabolical Puzzles.

How many Sudoku combinations exist?

There are exactly 6, 670, 903, 752, 021, 072, 936, 960 possible solutions to Sudoku (about 10^21) . That's far more than can be checked in a reasonable period of time. But as luck would have it, it's not necessary to check them all. Various symmetry arguments prove that many of these grids are equivalent.

How do you solve swordfish Sudoku?

Requirements to apply the Sudoku Swordfish strategy

This means the player only needs to focus on one digit. The grid must contain 3 rows or 3 columns where the digit is a candidate to only 2 or 3 cells. Each cell must be connected to another by row/column, regardless of the shape created when they are linked.

What is the secret in Sudoku?

A hidden pair in Sudoku is “When a pair of numbers appear in exactly two squares in a row, column, or block, but those two numbers aren't the only ones in their squares,” according to thonky.com.