The New Sudoku Players' Forum

[Terri]

I am not able to solve the puzzle in the Friday, February 23 Washington Post. I've been able to solve the hard puzzles for quite some time now, but this one has me stumped.

Here is the original puzzle:

*9* | *** | **2
**5 | **2 | ***
3** | 51* | *7*

**8 | *7* | 2**
*** | 461 | ***
**7 | *9* | 4**

*2* | *46 | **9
*** | 8** | 6**
5** | *** | *8*


Here is the puzzle filled in with what I have been able to solve so far:

*9* | *** | **2
**5 | **2 | ***
3*2 | 51* | *7*

**8 | 375 | 2**
25* | 461 | ***
**7 | 298 | 4*5

82* | *46 | **9
*** | 85* | 62*
5** | *2* | *8*

I can see the naked pair in column 5 and row 5, but past that I can't see what to do next. Any suggestions?

Thanks!

[udosuk]

There is a naked quad/hidden triple on r1 (assuming you got the locked candidates on 3)...

[Terri]

Thanks for pointing that out. Now that I know what I am looking for it is very easy to see. So far I haven't had to use anything more complex than finding a naked triple to solve the hard Sudoku in the Washington Post. I feel like I really learned something today. Thanks!

[Pat]

There is a naked quad/hidden triple on r1 (assuming you got the locked candidates on 3)

yes, r1,
but it's a "hidden" duo {3,8}

a nice puzzle, but no trio needed
(therefore wouldn't qualify as "superior")

[udosuk]

There is a naked quad/hidden triple on r1 (assuming you got the locked candidates on 3)

yes, r1,
but it's a "hidden" duo {3,8}

Oh yeah... Wasn't checking carefully enough... But some solvers regard a naked quad easier than a hidden pair/duo...

The correct solving sequence (without triples/quads) from your position:

Locked candidate of 3s @ c6
Naked pair {39}/hidden pair {78} @ r5
Locked candidate of 3s @ c8
Hidden pair {38} @ r1
All singles left (1 hidden single + 43 naked singles for solvers that regard naked singles as the simplest move...)