NOT KNOWN DETAILS ABOUT SUDOKU HARD - HARD SUDOKU

You can find a handful of patterns most players try to find at this time. Patterns make reference to configurations of solved squares that aid players often resolve a sequence of candidates.​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​�