WHAT DOES SUDOKU HARD - HARD SUDOKU MEAN?

Hard sudoku is usually practical in the development of Mastering Superior resolving strategies, but It is usually played by amateurs and specialists of sudoku. is a superb schooling in procedures of detection of duplicates, triplets and other tactics.​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​