## Rare Logical Trick

Advanced methods and approaches for solving Sudoku puzzles

### Rare Logical Trick

I recently came across a logical method I had not seen before and have not seen again. It might be seen as a "cheat" by some but I was pleased to find it. A partial diagram of the situation:

X X X X X X
X X 23 23 239 X
X X 23 23 X X

I realized the 9 could NOT be in the place it was posited. The puzzle would not be solvable if the 2 or 3 were not in that cell (the 239 cell).

This depends on whether the puzzle is solvable, which I assumed, as we do, that it was. The puzzle was solvable by more normal methods also.
Jumper

Posts: 8
Joined: 23 September 2005

### Re: Rare Logical Trick

post cancelled
Last edited by tso on Fri Sep 23, 2005 8:45 pm, edited 1 time in total.
tso

Posts: 798
Joined: 22 June 2005

Yeah, the diagram was a little off I think. I assume what you meant to describe was the tactic where you have something more like

23 23
23 239

And you put the 9 in the bottom-right cell because otherwise there could be no unique solution. It's been described in a few threads already.
PaulIQ164

Posts: 533
Joined: 16 July 2005

### Oops, PaulIQ164 is correct

PaulIQ164 wrote:Yeah, the diagram was a little off I think... more like

23 23
23 239

And you put the 9 in the bottom-right cell because otherwise there could be no unique solution. It's been described ...already.
Jumper

Posts: 8
Joined: 23 September 2005

In my experience PaulIQ164 is usually correct, tso sometimes makes mistakes - but then he has a lot more than most of us going on in his head!
emm

Posts: 987
Joined: 02 July 2005