## what is x wing and swordfish

Advanced methods and approaches for solving Sudoku puzzles

### what is x wing and swordfish

Hi I'm new to sudoku and this site (NY Post started printing them)
and don't understand how you refer to boxes or cells and saw a reference to x wing and swordfish can someone answer newbie question?

bruce
Guest

You might want to read http://forum.enjoysudoku.com/viewtopic.php?t=2

And, you certainly shouldn't worry about what a Swordfish is, you never need them (or atleast not for the puzzles generated by Pappocom).

An X-wing is only needed for the Very Hard puzzle, so nothing to worry about (yet). (I'm also unsure wheter or not the NY Post publishes Very Hard puzzles or not)
Animator

Posts: 469
Joined: 08 April 2005

### NY Post

Every day the NY Post publishes two puzzles -- always a "very easy" puzzle and a "tougher" puzzle.
chipe

Posts: 6
Joined: 26 April 2005

Animator wrote:You might want to read http://forum.enjoysudoku.com/viewtopic.php?t=2

And, you certainly shouldn't worry about what a Swordfish is, you never need them (or atleast not for the puzzles generated by Pappocom).

An X-wing is only needed for the Very Hard puzzle, so nothing to worry about (yet). (I'm also unsure wheter or not the NY Post publishes Very Hard puzzles or not)

'X-wing' is not explained in that topic...

edit: nevermind: http://www.simes.clara.co.uk/programs/sudokutechnique6.htm
quite easy actually
Time^-

Posts: 2
Joined: 31 May 2005

I don't get the x-wing...

What does it mean by this statement?

So, whether the 9s are in top-left and bottom-right, or bottom-left and top-right, it excludes 9s from the other cells in both columns, so 9 can be eliminated from the candidates for both columns.

that the 9's must be located in the highlighted boxes?
Guest

Posts: 312
Joined: 25 November 2005

It means that the number 9 of column 2 and the number 9 of column 9 has to be in one of the highlighted cells.

The only possibility for the number 9 in column 2 and in column 9 is in one the highlighted cells.
Animator

Posts: 469
Joined: 08 April 2005