53x15
  • Member for 2 years, 5 months
  • Last seen this week
The Existence of Total False Sudoku
5 votes

I offer no proof, but some evidence: An 87-clue Pencilmark Sudoku: +=====+=====+=====+=====+=====+=====+=====+=====+=====+ | 1.. | 123 | 123 | 123 | 123 | 123 | 123 | 123 | ..3 | | ..6 | 4.6 | .56 | ...

View answer
Most leads in a "difficult" Sudoku
Accepted answer
4 votes

Have a look at the thread below which catalogs the most clueful puzzles discovered at each Sudoku Explainer difficulty rating: http://forum.enjoysudoku.com/maximum-number-of-clues-for-a-given-se-...

View answer
Was "Crook's algorithm" for Sudoku really only developed in the 21st century?
Accepted answer
3 votes

When designed for speed rather than adherence to human solving process, and with the notable exception of those based on exact cover, most of the Sudoku solving algorithms I've seen are functionally ...

View answer
Does "naked set" method always solve a sudoku?
Accepted answer
2 votes

As tehtmi mentioned in a comment above, you can confirm using Andrew Stewart's solver that these techniques do not suffice for most difficult Sudoku. But more generally, if your main goal is to write ...

View answer
Logical Sudoku - How to tell when fully deducted?
2 votes

From the standpoint of propositional logic if a Sudoku has a unique solution then that solution (and every step leading up to it) can always be reached by a logical deduction. Put another way, for ...

View answer
Alice and Bob play at cards
1 votes

The players ante a sequence of odd numbers, so if a round ends after $x$ pairs of cards are drawn then a player's payoff is $\pm x^2$. Since the players break even after three rounds we must have $x^...

View answer