## Naked Quad Example

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### Naked Quad Example

I'm sure it's no big deal to experienced Sudoku Generators / Compilers, but according to Sudoku Explainer my Puzzle Generator just randomly created it's first puzzle with a Naked Quad.

For anyone looking to test their ability to solve Naked Quads, try the following:

Code: Select all
`000000000000031600000008090019800050600070030200000700100020080860059200000100045`
civiliza

Posts: 64
Joined: 25 October 2010

### Re: Naked Quad Example

Nice, puzzle, hard on paper.

For me its easier to see the hidden quad (like the hidden pair 16 before), which still does not give you a number directly ...
Code: Select all
` +-------+-------+-------+ | x x 16| . 9 . | x . x | | . . . |*5*3 1 | 6 . . | | . . 16| .*4*8 | . 9 . | +-------+-------+-------+ | 7 1 9 | 8 6 3 | .*5 2 | | 6 . . | . 7 . | .*3 . | | 2 . . | . 1 . | 7 6 . | +-------+-------+-------+ | 1 . . | . 2 . | .*8 6 | | 8 6 . | . 5 9 | 2 . . | | . . . | 1 8 6 | .*4 5 | +-------+-------+-------+`
eleven

Posts: 1665
Joined: 10 February 2008

### Re: Naked Quad Example

What would be the next move from here?
Code: Select all
`*--------------------------------------------------------*|  345    38    16 |  267     9    27 |   58   127   348 ||   49    89    27 |    5     3     1 |    6    27    48 ||   35    27    16 |  267     4     8 |   15     9   137 ||------------------+------------------+------------------||    7     1     9 |    8     6     3 |    4     5     2 ||    6    45   458 |  249     7   245 |   18     3   189 ||    2   345  3458 |   49     1    45 |    7     6    89 ||------------------+------------------+------------------||    1  3459   345 |  347     2    47 |   39     8     6 ||    8     6    34 |   34     5     9 |    2    17    17 ||   39    27    27 |    1     8     6 |   39     4     5 |*--------------------------------------------------------*`
evert on the crashed forum

dyitto

Posts: 118
Joined: 22 May 2010
Location: Amsterdam

### Re: Naked Quad Example

dyitto wrote:What would be the next move from here?

I think a XY-wing in r13 should take care of that.

But there's also a quite interesting BUG-lite:
Code: Select all
`*--------------------------------------------------------*|  345    38   *16 | *267     9    27 |   58  *127   348 ||   49    89   *27 |    5     3     1 |    6   *27    48 ||   35   *27   *16 | *267     4     8 |   15     9  *17+3||------------------+------------------+------------------||    7     1     9 |    8     6     3 |    4     5     2 ||    6    45   458 |  249     7   245 |   18     3   189 ||    2   345  3458 |   49     1    45 |    7     6    89 ||------------------+------------------+------------------||    1  3459   345 |  347     2    47 |   39     8     6 ||    8     6    34 |   34     5     9 |    2   *17   *17 ||   39   *27   *27 |    1     8     6 |   39     4     5 |*--------------------------------------------------------*`

that would suggest r3c9=3.

RW
RW
2010 Supporter

Posts: 1000
Joined: 16 March 2006

### Re: Naked Quad Example

Code: Select all
`*--------------------------------------------------------*|  345    38    16 |  267     9    27 |   58   127   348 ||   49    89    27 |    5     3     1 |    6    27    48 ||   35    27    16 |  267     4     8 |   15     9   137 ||------------------+------------------+------------------||    7     1     9 |    8     6     3 |    4     5     2 ||    6    45   458 |  249     7   245 |   18     3   189 ||    2   345  3458 |   49     1    45 |    7     6    89 ||------------------+------------------+------------------||    1  3459   345 |  347     2    47 |   39     8     6 ||    8     6    34 |   34     5     9 |    2    17    17 ||   39    27    27 |    1     8     6 |   39     4     5 |*--------------------------------------------------------*`

Another possibility : avoiding the deadly pattern 45 in r56c26 leads quickly to r5c6=2
aran

Posts: 334
Joined: 02 March 2007

### Re: Naked Quad Example

eleven wrote:For me its easier to see the hidden quad ...

Strange you should mention that:
Code: Select all
`000000000679000008010006209500960001200850000000000000050200306008040705706005090`
civiliza

Posts: 64
Joined: 25 October 2010

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