## Help with National 2008 advanced?? How to proceed?

Post the puzzle or solving technique that's causing you trouble and someone will help

### Help with National 2008 advanced?? How to proceed?

I tried solving the National 2008 advanced (target 7:38), but I'm stuck at this point. Any help how to proceed?

I tried few online solvers. They either just give the solved result (which doesn't help me learn how to solve it), or they get even lousier option than what I have deducted already. Any help would be appreciated.

Thanks.
tpatana

Posts: 3
Joined: 18 January 2009

### Re: Help with National 2008 advanced?? How to proceed?

Look at the pair 59 in column 9 (you have used it in the box only). Another pair then can solve it.

tpatana wrote:I tried few online solvers...
There should be better ones, but i dont have links. Two good (and free) programs, which can help you also for harder puzzles are Sudoku Explainer and JSudoku.
eleven

Posts: 1863
Joined: 10 February 2008

### Re: Help with National 2008 advanced?? How to proceed?

eleven wrote:Look at the pair 59 in column 9 (you have used it in the box only). Another pair then can solve it.

Ah, there is typo in r3c9, there wasn't supposed to be 9 inside.

Oh wait, do you mean that from r7c9 and r9c9, and then r1c1 and r9c1, the 59-pairs force r6c1 to be 8? That'd be correct answer, I'm just not sure about the logic if it works or not??

I'd really like to learn how to solve these really difficult ones, I'm just not there yet
tpatana wrote:I tried few online solvers...
There should be better ones, but i dont have links. Two good (and free) programs, which can help you also for harder puzzles are Sudoku Explainer and JSudoku.

Thanks for these, I'll have to take a look.
tpatana

Posts: 3
Joined: 18 January 2009

At first glance: Doesn't exactly blow the puzzle apart, but there is a column-based finned x-wing on 8s c49r34 (purposely reversed), fin at r2c4 => r3c5<>8 and a 2-string kite: (8)r16c1/r5c35: r1c5<>8
Last edited by DonM on Mon Jan 19, 2009 5:43 am, edited 2 times in total.
DonM
2013 Supporter

Posts: 475
Joined: 13 January 2008

### Re: Help with National 2008 advanced?? How to proceed?

tpatana wrote:Ah, there is typo in r3c9, there wasn't supposed to be 9 inside.
If it's a typo then you're really getting low on options for that 9 in r3 or box 3....

Luke
2015 Supporter

Posts: 435
Joined: 06 August 2006
Location: Southern Northern California

### Re: Help with National 2008 advanced?? How to proceed?

Luke451 wrote:
tpatana wrote:Ah, there is typo in r3c9, there wasn't supposed to be 9 inside.
If it's a typo then you're really getting low on options for that 9 in r3 or box 3....

You're right.

And with the help of the Sudoku Explainer (posted by eleven), there were several hidden singles out there, which opened it up quite easily.

Need bigger paper, this one was way too messy to find out those by myself

Thanks for the help guys. Now I just need to learn to crack this in 7:38 by pure logical reasoning.
tpatana

Posts: 3
Joined: 18 January 2009