I've received a lot of interesting comments and questions from Sudoku fans over the last few years and this page
is where I try to answer them. I'm also directing Str8ts feedback here. Please feel free to drop me a note on the side of the page. Or you can email me directly at email@example.com.
Post a Comment or Question here...
Thank-you everyone for all your questions and contributions.
... by: Stephen, UK
However, some normal Sudoku can have a solution with uniqueness in the diagonals, but its no help unless you know that - which you can't until the puzzle is completed
... by: Robert, usa
... by: grommetik, Maryland, USALoad Sudoku: CLICK TO LOAD
(Row-Col) 5 taken off F6, SF=DFH159
(Row-Col) 5 taken off H2, SF=DFH159
My understanding is that a common candidate must be in all of the 3x3 cells. 5 is not in cells D1 and H9.
... by: Kirk, Canada
If, for example...
... I got...
All Solutions to a Sudoku
There are simply too few clues for a solution count to be able to return a value in a reasonable amount of time. This may or may not be a valid sudoku with a single solution.
... But quarter rotate the board (clockwise -- arrow button)...
... it gave what I believe is the one correct end result. Just thought to share this bit of info.
Hope that’s interesting
... by: Chuck, Virginia
I have noticed that all of the "hidden pairs" examples I have seen, both on your site and others, do not have any candidates that can be removed from the "hidden pair" once it is made "naked". For example, if the hidden pair is made up of 4s and 7s, there are no 4s or 7s that can be eliminated. Only the numbers that are hiding the "hidden pair" can be eliminated. Is that just a coincidence or is that a hard fact? I guess I'm missing something here, please help.
They produce a Naked set after eliminations. Where a Naked set goes onto remove more candidates will only occur in another different unit. For example a Pair might be uncovered in a Box but then the same new Naked Pair can go on to remove candidates in a column (outside the box). This happens a lot in Jigsaw Sudoku
... by: Dave G, Uk
... by: fbax, Canada
Killer Hard Combinations
KILLER COMBO (Hard) on cage starting on A2: cage of size 3 with clue of 13+ can only be 1/2/3/4/5/6/7/8/9
- we can remove 9 from B2
I can see the virtue of expanding the result explanation to explain this, tricky to generalise
... by: John, Wisconsin, USA
I really like your website and book--well done!
My brother and I do Sudoku remotely, and often compare our solutions to yours. Recently my brother got the edge on me when he discovered W-wing, which I'm pretty fuzzy on. I didn't see it anywhere on your site--am I missing something?
Did this W-Wing appear in the solver?
... by: Brian, US
... by: Bob Lester, USA