WHAT DOES SUDOKU HARD - HARD SUDOKU MEAN?

Quads tend to be rarer, and so they’re significantly less practical in a way due to the fact they don’t Enable you to narrow down a lot of candidates abruptly, however, if you spot a single, it’s really worth investigating. Solving single squares may also switch quads into triples or pairs, so don’t forget about these!The two medium and har